I need a new battery [Archive]

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Flashjammin

3rd February 2011, 21:44

EJK

3rd February 2011, 21:47

hayd3n

3rd February 2011, 22:36

yousa:yes:

Gibbo89

3rd February 2011, 23:24

motobatt is meant to be okay from what i've heard

Paul in NZ

4th February 2011, 06:20

I have not yet finished writing this but...

Batteries come in many different types and sizes and we need to make sure the unit we fit is suitable for the application you have in mind. If we go back to the old fashioned lead acid battery (now called a flooded cell) your parents grew up with. These go back to 1859 and were invented by a Frenchman. They are effectively the oldest rechargeable battery known and have obviously had a fair amount of development over the years. The lead / acid batteries ability to supply high surge current means that the cells maintain a relatively large power to weight ratio and that coupled with low cost, make them attractive for use vehicles – particularly once electric starting became the norm. To function properly, these batteries do require you to add distilled water occasionally. This is important on a 60’s British bike as voltage regulation is a bit rough and it can get high enough to cause gassing and water loss.
Since the 1980’s we have seen the rise of the ‘sealed’ battery. Technically these are all VRLA batteries (valve-regulated lead-acid battery). Because of their construction, VRLA batteries do not require regular addition of water to the cells. VRLA batteries usually come in two flavours:
• Absorbed glass mat battery (agm)
• Gel battery (gel cell)
These batteries are often colloquially called sealed lead-acid batteries, but note that they always include a safety pressure relief valve. The name "valve regulated" does not wholly describe the technology; these are really "recombinant" batteries, which means that the oxygenevolved at the positive plates will largely recombine with the hydrogen ready to evolve on the negative plates, creating water and so preventing water loss. (ie you never need to top them up like you do in an old lead acid ‘wet’ battery) The valve is a safety feature in case the rate of hydrogen evolution becomes dangerously high. Note that these sealed batteries are still lead acid and share many features of the old wet flooded cell units. One reason they are so popular is that you don’t have to add water which means one less chore.
Lets look at these modern units in a little more detail.
Absorbed glass mat (AGM) is has the electrolyte (acid) held on the glass mat separator by way of capillary action. AGM batteries were developed by Concorde Aircraft Battery, in the late 1980s in San Bernardino California. The AGM battery technology was developed to be a warm weather, vibration resistant, and chemical alternative to the expensive Ni-Cad batteries in both naval helicopters and fighter aircraft.
AGM batteries are just like flooded lead acid batteries, except the electrolyte is being held in the glass mats, as opposed to freely flooding the plates. Very thin glass fibers are woven into a mat to increase surface area enough to hold sufficient electrolyte on the cells for their lifetime. The fibers do not absorb nor are affected by the acidic electrolyte they reside in. These mats are wrung out 2-5% after being soaked in acids, prior to manufacture completion and sealing. The AGM battery can now accumulate more acid than is available, and never spill a drop.
Advantages
All AGM batteries boast some significant performance enhancement over traditional flooded lead acid cells:
• AGM construction allows purer lead in the plates as each plate no longer needs to support its own weight based on the sandwich construction with AGM matting. Traditional cells must support their own weight in the bath of acid.
• un-spillable
• high specific power or power density, holding roughly 1.5x the AH capacity as flooded batteries based on purer lead]
• low internal resistance allowing them to be charged and discharged quite rapidly
• never requiring addition of water
• acid is encapsulated in the matting
• will operate well below 0°F or -18 °C.
• vibration resistant based on the sandwich construction.
Disadvantages
• Cost. AGM automobile batteries for example, are typically about twice the price of flooded-cell batteries in a given size.
• AGM batteries have up to a 10 year lifespan, but must be sized to discharge less deeply than the traditional flooded batteries. For an AGM battery, the depth of discharge for optimal performance is 50% but flooded batteries can be rated up to 80% depth of discharge.
• AGM batteries do not tolerate overcharging. Overcharging dissociates the water in the electrolyte, which is unable to be replaced, leading to premature failure.
Gel battery
A gel battery (also known as a "gel cell") is a VRLA battery with a gelified electrolyte; the sulfuric acid is mixed with silica fume, which makes the resulting mass gel-like and immobile. Unlike a flooded wet-cell lead-acid battery, these batteries do not need to be kept upright. Gel batteries reduce the electrolyte evaporation, spillage (and subsequent corrosion issues) common to the wet-cell battery, and boast greater resistance to extreme temperatures, shock, and vibration. Chemically they are the same as wet (non-sealed) batteries except that the antimony in the lead plates is replaced by calcium.
Applications
Many modern motorcycles on the market utilize AGM or factory-sealed AGM batteries for the combined benefits of reduced likelihood of acid spilling during accidents, and for packaging reasons (lighter, smaller battery to do the same job; the battery can be installed at an odd angle if needed for the design of the motorcycle).
The AGM battery is rapidly becoming the standard motorcycle battery!
Starting / Deep Cycle

Technology aside, the battery comes in two basic types and its important to know the difference.

Starting Batteries (found on vehicles) are designed with lots of thin plates to give a large surface area and thus can deliver a high starting current. However – they are not designed for deep discharges or regular cycling (discharge – charge). This is what often kills them – letting your battery get totally flat is a very bad thing indeed!

Deep Cycle Batteries are made with much thicker plates (more robust but less surface area) so they deliver less surge current BUT they can withstand many more discharge cycles. You will see these in UPS’s, golf carts, mobility scooters (well the good ones), fork lifts etc.

There are hybrids that are someplace between these extremes and are used in large boats, camper vans etc.

If your bike does not have electric start you are probably best served by a deep cycle unit but frankly good luck finding one small enough!

Technical Spec’s
Now we are going to get a bit technical so grab a coffee and hold on….These are general voltage ranges for six-cell lead-acid batteries (that’s 12v):
• Open-circuit at full charge: 12.6 V to 12.8 V (2.10-2.13V per cell)
• Open-circuit at full discharge: 11.8 V to 12.0 V
• Loaded at full discharge: 10.5 V.
• Continuous-preservation (float) charging: 13.4 V for gelled electrolyte; 13.5 V for AGM (absorbed glass mat) and 13.8 V for flooded cells
• Typical (daily) charging: 14.2 V to 14.5 V (depending on manufacturer's recommendation)
• Equalization charging (for flooded lead acids): 15 V for no more than 2 hours. Battery temperature must be monitored.
• Gassing threshold: 14.4 V
• After full charge, terminal voltage drops quickly to 13.2 V and then slowly to 12.6 V.
•

PLEASE NOTE!!
1. All voltages are at 20 °C (68 °F), and must be adjusted -0.022V/°C for temperature changes.
2. Float voltage recommendations vary, according to the manufacturer's recommendation.
3. Precise float voltage (±0.05 V) is critical to longevity; insufficient voltage (causes sulfation) which is almost as detrimental as excessive voltage (causing corrosion and electrolyte loss)
Which Battery For My Bike?
Well this is all very nice isn’t it but enough of the BS which battery do you fit to your bike? Again – this is just my opinion so please don’t turn up at my door with burning torches, pitchforks and white sheets pushing your bike with a flat battery.

My feeling is;

Modern bike – electric start – AGM
Classic bike – electric start – AGM
Classic bike – kick start, zenner control – flooded cell
Classic bike – kick start, solid state - AGM

There are many old bikes running AGM’s with no problems BUT if you are still running a zenner or horror a switched load system then a flooded cell (trad wet cell) battery may be best. Typically you can be placing 14.8V charge at 100kph (no lights) charge at the battery and in my opinion the wet cells take that a little better. They WILL fail so replace them at the first sign but they are half the price!

Redmoggy

4th February 2011, 06:41

Hawkeye

4th February 2011, 06:50

notme

4th February 2011, 07:02

Paul - very nicely written!

Flashjammin - you haven't said why your battery needs replacing - has the bike been sitting for 30 years or is it your daily ride and has just stopped suddenly?

Check point 3 here unless you are sure that the battery is the problem, or you might be in the same boat again sooner than you'd like:facepalm:

http://www.kiwibiker.co.nz/forums/showthread.php/132696-Basic-troubleshooting-steps

Oh, BTW Japanese branded batteries are generally better quality than Chinese.

Paul in NZ

4th February 2011, 07:09

Only one issue Paul. Under real world circumstances some older charging systems will not keep a Calcium based battery charged. They just don’t have the output. I work in the motor trade and am having more and more problems with replacement Calcium battery’s (all that is available for some applications) coming back flat. This may well be a teething problem with new technology but it causes me issues on a fairly regular basis. Also Calcium battery's require a different charger for bench charging.

Made for good reading

Roy

Yup - Thats one of the areas I need to look at. It often depends how efficient the rectifier is and (I suspect) sensitive the system is to the internal resistance / capacitance of the battery. I've had it suggested that you need to couple 2 of the AGM units in parallel when using an older charger. Worst of all, some so called 'tenders' struggle to sense when a smaller unit is fully charged.

I've done a lot of reading on non auto batteries, particularly rechargables and its interesting stuff. Charge rates vary enough to suggest you can totally root a modern sealed unit with the wrong charger.

End of the day - I'm fitting a Yuasa flooded cell at $54 rather than an AGM at $110. The reason being I have a good run from a std battery (5 years plus) and have the gear to maintain them so....

Redmoggy

4th February 2011, 07:46

Li-poly technology is interesting,if a little scary!

For now, for my application i am also staying with Led Acid. I would suggest anyone looking to 'upgrade' on an older bike spend some time checking there charging system.

Back on track though. If your certain the fault lies with the battery check the manufacturers spec and buy a quality brand from a respectable supplier. Avoid factory seconds (there is a reason they are seconds). Personally i have had no problems with Yuasa.

notme

4th February 2011, 07:55

I've done a lot of reading on non auto batteries, particularly rechargables and its interesting stuff. Charge rates vary enough to suggest you can totally root a modern sealed unit with the wrong charger.

End of the day - I'm fitting a Yuasa flooded cell at $54 rather than an AGM at $110. The reason being I have a good run from a std battery (5 years plus) and have the gear to maintain them so....

The core of the issue is that as soon as you change the chemistry of the battery, you need to change the charging scheme. No 2 battery types have the same charging profiles, but you get away with a bit if they are close enough.

Automotive systems are designed for lead acid batteries, there are workarounds and compromises you can make to use other types but you need to have a clear goal in mind - e.g. weight savings for the knife edge of racing where grams count, or reserve capacity if you are trekking across the desert or whatever.

Edbear

4th February 2011, 08:01

Hi everyone,
I'm wanting to get a general opinion on what type of battery is good/bad and which one people would recommend is the best.

I need to buy a new battery, my current one is pretty shot and no longer holds a charge hence the bike wont run :(

Check the thread on Shorai batteries. I hope to be able to get more in stock end Feb, but if you want one I can ask if I can get in a couple more "evaluation" batteries... I've got one here I was going to take to Paeroa on 20th to show everyone. Death_Inc has the other one in Draco's R6 for testing...

firefighter

4th February 2011, 08:40

Edbear

4th February 2011, 08:54

Don't over think it, Motobatt is more than sufficient. I've bought two and they're fine. SHit a Besco one from Repco will will probably be sweet really.

If it costs you over $120, and that's being generous, you are paying more than you should.

Well of course, there is that... As long as the charging and electrical system is in good shape simply replacing with a new one will work fine. However where the Shorai ones do win is in battery life which is claimed up to 4x standard, (and in weight and starting capacity), so if you add up the purchase costs of 3 - 4 standard batteries they start looking good value for money.

firefighter

4th February 2011, 09:03

Well of course, there is that... As long as the charging and electrical system is in good shape simply replacing with a new one will work fine. However where the Shorai ones do win is in battery life which is claimed up to 4x standard, (and in weight and starting capacity), so if you add up the purchase costs of 3 - 4 standard batteries they start looking good value for money.

Meh, look at his bike, I doubt he'll own it in a years time, so why waste a shite load of money on an expensive battery?

Edbear

4th February 2011, 09:12

Meh, look at his bike, I doubt he'll own it in a years time, so why waste a shite load of money on an expensive battery?

Horses for courses of course! :yes:

firefighter

4th February 2011, 09:15

Horses for courses of course! :yes:

Absolutely, i'm of-course a complete hypocrite, I always buy the most expensive 'quality' items I can find, spend stupid amounts of money then sell the bike months later......only three times in a row now :facepalm:

Henk

5th February 2011, 20:19

Absolutely, i'm of-course a complete hypocrite, I always buy the most expensive 'quality' items I can find, spend stupid amounts of money then sell the bike months later......only three times in a row now :facepalm:

Don't cry, you're not the only one who buys bikes, spends a fortune in cash and time fixing them and then sells them for less than they paid :brick:. On the bright side we do occasionaly get something that needs little or no attention and then run it til it dies.

Edbear

5th February 2011, 20:36

Don't cry, you're not the only one who buys bikes, spends a fortune in cash and time fixing them and then sells them for less than they paid :brick:. On the bright side we do occasionaly get something that needs little or no attention and then run it til it dies.

Yeah, I got married in '77... :innocent: :shutup: :facepalm:

Voltaire

7th February 2011, 07:01

Good post Paul, my 'new' Commando has a a non flooded lead acid battery and I don't think it likes the Commando charging system, was pondering the Motoplatt ones but think now I'll stick with the old skool one as I can maintain them.

scumdog

7th February 2011, 07:16

Good write-up Paul, tell me, what catagory are the Optima batteries??

Paul in NZ

7th February 2011, 07:21

I'm not sure - I've never seen them but old lead acid ones are easy to spot....

Paul in NZ

7th February 2011, 07:21

scumdog

7th February 2011, 07:24

I'm not sure - I've never seen them but old lead acid ones are easy to spot....

OK, what I know of them is: (I have one in the F100) they are sealed, hold a charge for a long time, start a hot engine easier and more often than the traditional old black batteries and are smaller and lighter,

Oh, and they have pretty red or yellow tops, grey too I think!

DMNTD

7th February 2011, 07:26

Don't over think it, Motobatt is more than sufficient. I've bought two and they're fine. SHit a Besco one from Repco will will probably be sweet really.

If it costs you over $120, and that's being generous, you are paying more than you should.

100% agreed...have sold many of this brand (2 year warranty) and have yet to hear a negative comment.

Paul in NZ

7th February 2011, 07:37

AGM is a great technology BUT it is not the best solution to all applications... Most motorcycle systems are pretty light weight and early AC systems are very very basic. If you have a later bike with a sound system, AGM is the way to go.

notme

7th February 2011, 08:12

Good write-up Paul, tell me, what catagory are the Optima batteries??

.......Oh, and they have pretty red or yellow tops, grey too I think!

Did a project with Optima years ago - the chemistry is AGM with "special" spiral plates rather than flat. The different colour tops denote different applications like starting, marine etc.

Flashjammin

7th February 2011, 12:01

Hi guys,
thanks for the help.

Paul - very interesting reading sounds like you have done quite a bit of research on batteries.

Ive just gone down to the local Suzuki shop and got them to order me a Yuasa battery for $80. Hope they are as good as everyone says. I did have a quick look at Motobatt but like someone else pointed out...there isn't much point spending more on a battery than I need to although I have just found one on TradeMe for $83.

The bike was sitting for 2 days over the weekend and wouldn't start on Monday when I went to go to work. Previously I have had to charge the battery fully as when I checked it there was no water in it so I think from then it was pretty shagged. The plates inside looked pretty rusty so probably about time for a change.

The AA man was here the other day cos the mother-in-laws car battery packed in and i got him to test it for me and he couldnt get a reading and said that it was something not connecting in the battery.

Will update later in the week when i get the new battery.

notme

7th February 2011, 12:20

Just make sure you test the system once you get the new battery, or you might be back at the dealer again in short order! :facepalm:

Bender

16th February 2011, 19:44

I have a 1973 Honda CB125 that was refurbished and converted to 12V. High quality restoration.

It sat in a garage for quite a few years and I got it running again with loads of help from Lloyd at Kingsland motorcycles. OK, he did the lot.

I seem to have a battery capacity issue. The battery is pretty tiny but there is no room on the bike for a bigger one without some drastic modification.

There seems to be no problem with charging - I'm getting 15 volts at the battery when I put the multimeter on the terminals. But over time the battery is running down as I ride the bike. Over about 300 miles it dropped from 12.8 volts to 10.5 which is when I noticed (bike getting harder to start).

When I first got the bike running the headlight would run the battery down in 20 miles. I reduced the power of the light bulbs.

It seems to be OK with the headlight off, (speculation because I have not been able to do 300 miles with the headlight off, but I often sneak it off to charge up the battery, especially in the few miles before home). It runs down when I have to run the headlight which is, of course, required by law.

The bike runs a quartz halogen H4 bulb (I modify the base so it fits the ancient headlight). Originally it was 80/100 watts. I put in a 55/60 watt bulb. I also reduced the tail light by 10 watts.

The 55/60 H4 bulb is the lowest power bulb I could get. So I'm getting a lot further before running out of 'lecktrickery power, which suggests I am on the right track.

It's a relatively cheapo battery.

Can anyone suggest some solutions - where I might get a lower draw headlight bulb with the same H4 base but particularly, will getting a top quality battery like a Yuasa give me more capacity that will prevent the battery slowly dropping in voltage.

I'd appreciate any solutions, remembering that the conclusions I have come to regarding power draw by the headlight bulb etc may not be correct either.

notme

16th February 2011, 20:22

Yo Bender,

do you have any diagrams/service info either pre or post mod or can you find such for your model?

I believe the original system was an AC lighting type, i.e. a coil off the alternator just for lighting, battery only used for ignition.

Has it been upgraded to a "normal" motorcycle system - i.e. standard regulator rectifier and all lights powered off 12VDC?

If your charging system is working correctly, your battery should not run down, as the charging system will provide all power necessary to run the bike including headlights as well as charging the battery. You say that you have 15V at the battery - what rpm? You should have about that voltage at about 3000rpm - if you do, then the charging system is probably OK (see here (http://www.kiwibiker.co.nz/forums/showthread.php/132696-Basic-troubleshooting-steps?p=1129943048#post1129943048) for a comprehensive test chart)

However, you are saying the battery does run down......by the way - what do you do when it is flat? Put it on an external charger? I'm wondering if the charging system is in fact buggered, and the battery is just slowly running down all the time, but it dies quicker when you have the headlight on of course.

The point is, battery capacity should not be an issue, any standard IC engine battery is known as an SLI battery (Starting, Lighting, Ignition) and only exists to provide stored energy to turn the engine over. The capacity of the battery has very little bearing on the engine once it is running. If your charging system is working properly, it is always producing an excess of energy, which is converted to heat by the regulator/rectifier unit.

You have a multimeter, so can you run thorugh the chart linked above? note - try it with and without the headlight on.....

Bender

18th February 2011, 13:59

notme

18th February 2011, 15:25

Allun, many thanks for the help, which I've run through. The link to the motorcycle charging system fault finding flow chart doesn't work, but I used google to find this one (link) (http://www.electrosport.com/media/pdf/fault-finding-diagram.pdf) which I think is comprehensive.

hmm...link works for me, hopefully for others or i'll have to repost it....the one you have linked to is the same one anyway.

Well, this is where it gets interesting - your photos show a standard low frequency bridge rectifier! This is not a motorcycle regulator rectifier, it is just a standard low power general purpose electronic part.

So, your bike has been modded to 12V not by changing it to a standard motorcycle RR system, but by changing it to a custom system.

That means that the fault finding chart and anything else that would normally apply to troubleshooting a charging system doesn't apply!

I would imagine that the person that changed it put a stator out of a slightly different Honda into your alternator (with different windings to get a higher output), changed the rectifier, and put a 12V ignition coil in. That's about all I reckon you'd need to do to change a bike like yours from 6v to 12v - oh and 12v bulbs all round of course.

So, now your tale of woe regarding the headlight flattening the battery makes a lot more sense :-).

Big question - did the bike ever run fine i.e. no battery problems? If YES, then it has developed a fault and we can follow that path. If NO, then it was not modified properly in the first place, and we need to resolve that.

A couple of questions and answers:

........the bracket that connects it to the frame is connected to powder coat. Does this have to be well earthed, because it isn't.

No it doesn't. The case of the rectifier bridge is not connected to anything inside, so it can be earthed or not with no change. One reason to connect it to the frame without powder coat in between is heat transfer though - it will sink heat into the frame better without powder coat in the way. We can deal with this later after we solve the original problem - which may in fact be caused by poor heat dissipation anyway!

It has the number BR356 an an earth symbol a 97 moulded into it. Don't know if or what that means.

It's the part number - like most electronic components the numbers indicate the part ratings. This is a bridge rectifier (BR356) rated at 35 Amps (BR356) at 600V (BR356).

We can test this part easily enough - and the fix might be simply that this part has overheated and died, which would be excellent news for you.

To test it, we need to disconnect it from the bike - hopefully there are connectors that will help you here, otherwise you're going to have to desolder the wires or cut them. Take a photo before you cut or desolder any wires, and write which wire went where with vivid on the rectifier (after cleaning it up with meths).

Once the rectifier is off the bike, get your multimeter, and put it on diode test mode. The symbol for this mode will look similar to this:

232489

Check that when you touch the multimeter probes together the meter reads 0.00 on the display, and it will likely beep as well. Check that when the probes are apart the meter reads "OL" or maybe "--".

Touch one of the probes to the metal case of the rectifier - doesn't matter which one, and touch the other probe to each of the 4 terminal legs one by one. None should beep or read anything on the display apart from "OL".

Then test between the following points, and tell me what you get for each. You should get around 0.3 to 1.0 and a short beep that stops by itself even if you keep the probes connected to the rectifier, but definitely NOT "OL" or "0.00" and a continuous beep.

1. Put the black meter probe on the rectifier pin that had the yellow wire, and the red probe on the rectifier pin that had the red/white wire. What does the meter say?

2. Put the black meter probe on the rectifier pin that had the pink wire, and the red probe on the rectifier pin that had the red/white wire. What does the meter say?

3. Put the black meter probe on the rectifier pin that had the green wire, and the red probes on the rectifier pin that had the pink wire. What does the meter say?

4. Put the black meter probe on the rectifier pin that had the green wire, and the red probes on the rectifier pin that had the yellow wire. What does the meter say?

5. Now put the meter on resistance mode (ohms) and probe between the yellow and pink wires on the bike i.e. going back to the alternator stator. What's the reading in ohms?

I recommend a box of beer and a nice day in the sun to do all this, but that's just me :-)

Bender

20th February 2011, 10:02

Check that when you touch the multimeter probes together the meter reads 0.00 on the display, and it will likely beep as well. Check that when the probes are apart the meter reads "OL" or maybe "--".

My multimeter comes up with a 1 when I switch it to diode test mode, which I assume is the symbol it uses for that mode.

When I touch the leads together it goes to 0.00.

1. Put the black meter probe on the rectifier pin that had the yellow wire, and the red probe on the rectifier pin that had the red/white wire. What does the meter say?

1 (i.e. no change)

2. Put the black meter probe on the rectifier pin that had the pink wire, and the red probe on the rectifier pin that had the red/white wire. What does the meter say?

1 (no change)

3. Put the black meter probe on the rectifier pin that had the green wire, and the red probes on the rectifier pin that had the pink wire. What does the meter say?

1 (no change)

4. Put the black meter probe on the rectifier pin that had the green wire, and the red probes on the rectifier pin that had the yellow wire. What does the meter say?

1 (no change)

5. Now put the meter on resistance mode (ohms) and probe between the yellow and pink wires on the bike i.e. going back to the alternator stator. What's the reading in ohms?

Pink / yellow 1.7

Just a note, the wires coming from the stator are not standard colours. There is a blue wire, brown wire and three green wires.

I chose the wires that corresponded to pink and yellow on the connector box.

In answer to your question about whether the bike had a problem in the past, it is difficult to know. It sat in forum member Voltaire's garage for many years and had originally been ridden by his wife.

The rebuild of the bike was undertaken by a person who was something of a perfectionist. He did not rebuild the bike to factory standard but made a number of sensible modifications such as decent brakes, alloy rims and the 12V electrics.

The rebuild was done to a very high standard so I think that any problems are likely to have developed post-rebuild rather than during the rebuild. He also rode the bike for several years after the rebuild and I'm sure that if there had been a problem, he would have noticed and fixed it. I think (but of course nothing is ever certain).

notme

20th February 2011, 10:25

Can you try another set of readings, multimeter on diode test mode:

1. black probe to terminal that had the yellow wire, red probe to the one that had the green wire

2. black probe to terminal that had the red/white wire, red probe to the one that had the yellow wire

3.black probe to terminal that had the pink wire, red to the one that had the green wire

4. black probe to terminal that had the red/white wire, red to the one that had the pink wire

Hopefully these all read somewhere between 0.3 and 1.0, and they should all be the same (within a small tolerance).

Did you test that none of the terminals read anything between each of them and the metal case of the rectifier?

Bender

20th February 2011, 11:57

Here we go... I wasn't sure whether you meant the bridge rectifier or the wires from the stator so I did both.

1. black probe to terminal that had the yellow wire, red probe to the one that had the green wire

BR: 540
Stator: no change

2. black probe to terminal that had the red/white wire, red probe to the one that had the yellow wire

BR: 1195
Stator: 003 (note there is no red/white wire on that connector, so I used the white.

3.black probe to terminal that had the pink wire, red to the one that had the green wire

BR: 530
Stator: no change

4. black probe to terminal that had the red/white wire, red to the one that had the pink wire

BR: 515
Stator: 001

Did you test that none of the terminals read anything between each of them and the metal case of the rectifier?

Yes, no change in reading.

notme

20th February 2011, 15:00

BR: 1195

This one is a concern.

Does your multimeter have a current setting of at least 10 Amps?

Bender

21st February 2011, 09:58

Yes it does.

notme

21st February 2011, 10:32

Measure the battery current to see what's going on there. You'll need to plug your red meter probe into a different socket on the meter to measure current instead of voltage - please remember not to measure anything apart from current while you have the meter in this state or you will cause sparks!

So:

1. Plug the rectifier and everything back in as it was so the bike is back to running order. Leave the battery negative lead off.

2. Set up meter for current. You have to change the red probe to a different socket labeled DCA or CURRENT or 10A max, and set the dial to DC CURRENT or AMPS DC or DCA or similar.

3. Connect the black meter probe to the battery negative terminal, and the red meter probe to the battery negative cable. Make these connections good, maybe tape the connections securely or clamp the meter probe in the battery terminal or similar. Make sure they don't short out to other parts of the bike - remember the bike will vibrate with the engine running and they might move so maybe tape them to some part of the frame.

4. Start the bike, turn off as much electrical load as you can (mainly headlight) and observe the meter reading at idle. If the current reading is positive, the battery is charging, if the current is negative, it is discharging. Try varying the revs, turning the headlight on etc and note down some currents. Be careful note to do anything that makes the meter read more than about 5Amps for more than a minute or so, as the wires on your meter probes will start getting warm above that. If you do anything that reads more than 10A your meter fuse will blow.

When done, put the red meter probe back into the voltage measuring socket so you don't accidentally try and put the meter across your battery and blow the fuse!

Bender

21st February 2011, 14:30

I did that. Set up multimeter, black probe to battery negative, red lead to battery negative cable.

With the key switched on but the engine not running, the reading was 0.19.

Idle .61
Headlight on at idle 2.35 to 2.68
5000 rpm -1.25
5000 rpm headlight on .35
Idle headlight and blinker on 2.4 tp 3.3
Idle headlight, blinker, brake light on 3.5 4.2

5000rpm headlight, blinker, horn going .35 to .57

I hope you can see something in there because I can't.

notme

21st February 2011, 17:18

Well, now we know what's happening - the WHY is still not clear though.

First off - I made a mistake, with the meter connected the way I told you to, positive current direction means the battery is discharging, negative means charging. Sorry! It doesn't change the results but I thought I'd clarify so that you understand what I am saying below...

Ignition on, engine off 0.19A
Idle .61A
Headlight on at idle 2.35 to 2.68A
5000 rpm -1.25A
5000 rpm headlight on .35A
Idle headlight and blinker on 2.4A to 3.3A
Idle headlight, blinker, brake light on 3.5A to 4.2A
5000rpm headlight, blinker, horn going .35A to .57A

Basically if you look at the results, you can see that the only time the battery is charging is when you have revs and the headlight off.

In all the other tests, your battery is being discharged, just to different degrees. The worst is obviously when the headlight, blinker, and brake light are all on, and the bike is idling (no charge from the alternator).

When you have all these things on, and you give it revs, the alternator is providing almost all the current needed to run those things, except for the last 0.35 to 0.57A which must be provided by the battery. If you just revved a little bit more you might find that the number drops to 0 - when it drops to zero, the alternator is powering all the bike's loads, and the battery is not having to provide the top up. If you rev more, you should find that the number becomes negative, which means the alternator is providing more than the headlight etc need, and so the leftovers will go into charging the battery.

So, now we know that the problem is that the bike is not charging the battery. Which BTW is basically what you said in the beginning :yes:.

The question is - WHY.... well, I can only conclude that the alternator needs upgrading, it is just not providing enough juice. You could leave the alternator as is, and go back to the stock headlight, or keep the more power hungry headlight and upgrade the alternator. If you did that however, you would need a modern regulator rectifier unit, or you'd kill the battery fairly quickly. A modern bike has a shiteload more charging power avaialble (about 400W) so really the only "problem" here is that you are asking too much of the old girl.

Do you have contact with the previous owner to ask if this all sounds familiar? You might just get an answer like "oh yeah I would put it on a charger every couple of weeks" ....

BTW, well f$#kin done on being patient and going through this - I'm always happy to help but a lot of people would have given up by now :-) Hopefully you have learned a bit more about how your bike works, more importantly you haven't paid someone else to do what you'll have to admit was really a piss easy few tasks!

Bender

21st February 2011, 19:07

Thank you Allun for taking me through that. I also learned how to do one more thing on the multi meter. :yes:

Regards upgrading the alternator, I'd like some advice on how to go about that. Do I get the existing one re-wound, or is it going to be possible to get a better Honda one that will bolt straight in? Do I phone the dudes at Econohonda and suss out what might fit? It would be logical for Honda to use the same set up for a range of its smaller bikes, just changing the number of windings and coils. Wouldn't it? :facepalm:

Can I add some more windings to the charging coil of the existing set up. Do I need a new and better rotor?

I can understand throwing it on the charger from time to time and I may well end up doing that depending on the complexity and cost of the fix.

If I wasn't required by some dumb-arse law to keep the headlight on, it wouldn't be a problem. :argh: It's not a bike you spend a lot of time on at night.

I could change the headlight to the standard one that draws only 35 watts - would that be enough to solve the problem or would I also still need more jooce?

notme

21st February 2011, 21:17

Hey dude,

you are dead right on changing the stator - further evidence that you have actually been paying attention and following along :-)

Exactly as you say, you can stick another Honda stator into your bike and voila - more alternator output (search google - i am not expert on your bike but there seems to be lotsa info out there).

BUT.....yup, there's the but. It seems like at this stage you understand basically what's happening, i.e. that your alternator is not putting out enough grunt to charge your battery as well as light your headlight and indicators, brake lights etc.

So, you can see that increasing the alternator output fixes this - BUT the only thing limiting your battery charging current at the moment is your weak alternator.

If you had an alternator with more go, you could run a more powerful headlight, but would overcharge your battery. To stop this happening you could get a motorcycle regulator/rectifier which is a bit different to your simple rectifier bridge....and means a lot of wiring changes.

SO, maybe the person that converted your bike to 12V was actually quite on to it and decide to keep it simple.....at the expense of not being able to upgrade the weak stock headlight :-(

If you changed to the stock 35W headlight you miiiiight still have a problem, hard to say but you might just try it for a few weeks. You said that at idle with headlight off the battery is discharging by 0.61A, but when you rev (as you do normally while riding) it will charge...you might end up being OK, or having to only chuck it on the charger once every few months depending on how often you ride.

Another fix might be to fit a daytime running lamp that meets all the legal requirements but does not draw sp much power, for example a LED light. Are you even sure that the headlight must be on during the day for a 1970's bike? I'm not saying it's not a good idea, but it might be optional for a bike of your one's age.

Anyway - there are still things that can be done, but I think we have proven that you don't have much to worry about as far as faults go, there's nothing wrong with your bike as such, it's just not working the way it ideally would.

I'm happy to help with converting it to a "normal" motorcycle rectifier/regulator system if you want, but be prepared to get intimate with your wiring :-)

A

Bender

22nd February 2011, 08:38

Allun,

This morning I've wired in a 12V 35W incandescent headlight bulb and I'm getting good charge (.2 - 1.5A) pretty much from idle (I reversed the MM leads so I got proper + and - readings.)

So the way ahead is clear - revert to a crappy old headlight and obey the law.

I'll do a scout around today and see if there is any such thing as an H4 35W quartz-halogen bulb but I was told by the guys at the local Repco that such an animal didn't exist.

notme

22nd February 2011, 08:52

Cool - I'm glad we've established that there's no real fault as such, because it means yer bike ain't broken! It just uses a headlight as a charge regulator..... :-)

With the 35W headlight on permanently, the battery should get just enough current to charge well, without overcharging, so it looks like the best option.