New batteries

**vifferman** · 16th September 2005, 12:06

If you look at a battery website, like Yuasa, a battery is supposed to be put on a charger after the acid's added, not just used straight away.

If you put a multimeter across the battery terminals, the battery should read over 12V at rest; with the bike running, the voltage should increase as the revs do, ranging from over 13V at idle to over 14 at 5krpm.
Check also the terminals - make sure they are secure, and that the earth connection and other connectors in the charging system wiring loom are secure, have no corroded contacts, discoloured wires / plugs. (You can trace the wires backward from the battery to work out which wires to check: they'll go from the battery positive, through the main fuse and starter relay, to the R/R, from there to the stator.

**nudemetalz** · 16th September 2005, 12:14

Thanks Vifferman,

I checked out the terminals and they're absol fine. All the wiring looks fine too.
So I've got the wife to drop it passed Sawyers here in Welly to get the charge output checked as you say. Then it's just a process of elimination.

Chris.

**nudemetalz** · 16th September 2005, 12:15

BTW, VT's are dead-easy to push start,...the NZ-250 (single-cylinder) don't even bother !!!

**vifferman** · 16th September 2005, 12:19

Originally Posted by MSTRS

If a bike charges the same way as a car does, then your battery needs to be near if not fully charged for the charging system to work properly. Something to do with needing electricity to create electricity. Otherwise all you are doing is using the electricity from the alternator to 'subsidise' the battery powering the coils, lights etc.

Not exactly, Dude.
But if the battery is really sad, and your runs are short, then the battery will never get fully charged, as too little current is left after powering lights etc. It's just maths - a stator/alternator has a finite output, and the system is designed to not have a lot of watts spare, just a little left over after all the ignition, running lights, indicators etc are taken into account. On a long run, the battery will charge up OK, even if it started out pretty flat.
However, if the battery is REALLY sad, so it doesn't hold a charge, or the charging system has a fault, then the bike will conk out once battery voltage drops too low, as a minimum is needed to charge coils, run the fuel pump, etc.

**Zed** · 16th September 2005, 12:25

Originally Posted by vifferman

If you put a multimeter across the battery terminals, the battery should read over 12V at rest; with the bike running, the voltage should increase as the revs do, ranging from over 13V at idle to over 14 at 5krpm.
Check also the terminals - make sure they are secure, and that the earth connection and other connectors in the charging system wiring loom are secure, have no corroded contacts, discoloured wires / plugs. (You can trace the wires backward from the battery to work out which wires to check: they'll go from the battery positive, through the main fuse and starter relay, to the R/R, from there to the stator.

Good advice. It pays to check all these things out before shelling out for a new battery, this same principle applies to other parts of the bike as well, eg. I thought I had a serious problem with my engine making a knocking noise but it turned out to be a worn chain and sprocket/s...lucky I didn't pay someone to take the engine apart eh!

I too recently bought a new battery and within 6 weeks (surprised it lasted that long) it was dead flat. Turned out the be a faulty regulator/rectifier, so I could have saved buying the new battery to begin with!

**Flyingpony** · 16th September 2005, 12:28

Originally Posted by nudemetalz

My VT250 one musta been dirt cheap at $30 then !!!

Is your battery one with clear white plastic and red little caps on top of it?
You'll then also be checking and toping up its acid level from time to time.

They're cheaper than our units, by at least 1/2 price.
We're running black cap less sealed units. These are fit and forget.
My battery also carries part of the seat weight.

**nudemetalz** · 16th September 2005, 12:33

Yeah, mine's that with little white caps, but yes it's not sealed, so will have to check and keep the levels topped up.

Is there much difference between using distilled water and ordinary tap water for topping up ?

**Flyingpony** · 16th September 2005, 13:05

Originally Posted by nudemetalz

Yeah, mine's that with little white caps, but yes it's not sealed, so will have to check and keep the levels topped up.

Is there much difference between using distilled water and ordinary tap water for topping up ?

Tap water has extra impurities in it, while distilled water doesn't and thus is better to use than tap water.
Best to use battery acid itself as over time acid concentration might dilute making the battery ineffective.

Well, that's my understanding.

Anyway, I tend to use tap water which has been boiled. Have yet to find a place which sells battery acid.

**vifferman** · 16th September 2005, 13:12

You're OK topping up with just distilled water. If a battery hasn't physically lost any acid (by say, being tipped upside down) then there's no need to add more acid, and doing so may be a stupid idea. A non-sealed battery loses a little moisture (steam) as it charges, so the acid has become more concentrated. If you add more acid to it, you're doing the wrong thing.

Tap water contains dust, dissolved minerals, bacteria, alls sorts of crap. If you use this in a battery, it will cause sedimentation between the plates, which could short them out (meaning the battery has less voltage). Always use distilled water. I did this religiously with my VF500, and the battery was still going well after nearly 7 years in the bike!
BTW - you can buy distilled water from some supermarkets. We use it in the cars (bike has sealed battery), the steam-iron, stuff like that.

**vifferman** · 16th September 2005, 13:17

Originally Posted by Zed

I too recently bought a new battery and within 6 weeks (surprised it lasted that long) it was dead flat. Turned out the be a faulty regulator/rectifier, so I could have saved buying the new battery to begin with!

Yeah, but you always think that.
It probably wasn't a bad idea to buy a new one anyway.

You think that's bad - I did it TWICE! You'd think after having to replace the battery and R/R on the VFR750, when I started having the same symptoms on the VTR I'd be wise to it and check it out thoroughly.
No.
Firstly, I thought the VTR was immune (it's actually more prone to failures than the VFR, as the R/R is pathetically weedy). Secondly, I didn't do my testing properly. I looked at (some of) the symptoms, and jumped to a conclusion. Still had to replace the R/R, regardless of what I thought.

**nudemetalz** · 16th September 2005, 13:18

Ah right, thought distilled water was the way to go.

Cheers and love the V-4 Avatar Vifferman.

BTW, What model VF-500 did you own ?
I used to own one too, it was the second model (1986) which had a lower redline (11,500) and couple of extra hps.

Chris.

**vifferman** · 16th September 2005, 13:24

Originally Posted by nudemetalz

Ah right, thought distilled water was the way to go.

Cheers and love the V-4 Avatar Vifferman.

No worries.

Originally Posted by nudemetalz

BTW, What model VF-500 did you own ?
I used to own one too, it was the second model (1986) which had a lower redline (11,500) and couple of extra hps.

I think mine was a 1985. I bought it in 1994 and sold it in 2000.

**nudemetalz** · 16th September 2005, 13:28

I loved my VF500 and regretted selling it for the 1986 GSXR400.
Sure it was faster around corners and as fast in a straight line, but the VF could tour and criuse in comfort....ahhh the lusty 360o V4 motor, still remember it well.

Anyway getting off the subject here. I'll let you know what Mr Shop says about the R/R quality.

Thanks for all of the help, peoples

Cheers
Chris

**Ixion** · 16th September 2005, 13:56

Originally Posted by MSTRS
If a bike charges the same way as a car does, then your battery needs to be near if not fully charged for the charging system to work properly. Something to do with needing electricity to create electricity. Otherwise all you are doing is using the electricity from the alternator to 'subsidise' the battery powering the coils, lights etc.

Not exactly, Dude.
But if the battery is really sad, and your runs are short, then the battery will never get fully charged, as too little current is left after powering lights etc. It's just maths - a stator/alternator has a finite output, and the system is designed to not have a lot of watts spare, just a little left over after all the ignition, running lights, indicators etc are taken into account. On a long run, the battery will charge up OK, even if it started out pretty flat.
However, if the battery is REALLY sad, so it doesn't hold a charge, or the charging system has a fault, then the bike will conk out once battery voltage drops too low, as a minimum is needed to charge coils, run the fuel pump, etc.

What he was thinking of, is that the battery has to have enough power to excite the coils in the alternator. The old Lucas alternators used permanent magnets in the rotor. So once the engine was turning you always got power generated. But a lot of later alternators use coil rotor magnets. So there is no magnetism in the rotor until those coils are energised. Not enough current in the battery to energise the rotor coils = no current generated. So push starting on a TOTALLY flat battery may not work. But it has to be TOTALLY flat for that to apply.