View Full Version : Question about charging in a vtr250...
toyboy
25th August 2008, 00:19
Got a couple of mini 55watt spotties i was thinking of sticking onto the VTR250, will the alternator be able to keep up with the requirements if the main headlight is on as well as the spots?
motorbyclist
25th August 2008, 03:17
only one way to find out for sure:D
hayd3n
25th August 2008, 07:31
you should be fine! im using hotgrips and a radar most of the time and dont notice a difference
TimeOut
25th August 2008, 08:09
you should be fine! im using hotgrips and a radar most of the time and dont notice a difference
Maybe, your Oxfords and radar won't be drawing 40 watts even with the grips on 100%
HungusMaximist
25th August 2008, 17:07
One way to be sure if to find out your motorcycle's charging system output is flicking through your service manual.
In general, smaller bikes have less charging capacity than larger bikes and FI bikes have higer output than carbureted bikes.
Then you calculate the normal operating load for your motorcycle like total of all factory installed electrical devices that will be in operation during normal riding. Don't add turn signals or horn as it's used intermittently.
Generic operating loads for most caburetted bikes are around 195 watts and FI bikes are around 285 watts. Then you subtract the operating load from the peak charging output and this will predict the approximate excess power for your bike.
eg: Kawasaki ZX6R, Peak 305 watts, Operating 200 watts, Excess 105 watts
Component example: High beam 65 watts, low beam 55 watts, fuel pump 60 watts, cooling fan 60 watts, ignition 50 watts, licence plate 5 watts, etc...
Do note, idle bikes will not produce anywhere close to its peak output.
toyboy
25th August 2008, 18:19
Well heres the charging specs from the service manual
Battery ----
Battery capacity - 12V - 6AH (but i got a 7ah battery in there)
Leak current 0.1mA or less
Charging current/time (Rapid) 3.0A/1h
Charging current/time (Standard) 0.6A/5-10h
Regulator/Rectifier ----
Type Tri-phase AC regulator SCR type
Regulated voltage 12-16v/5000rpm
Alternator ----
Type tri-phase AC
Output 0.32kW/5000rpm
Charging coil resistance 0.1-1.0 ohm
Headlamp 12v 60/55W
Brake lamp 12v 23/8W
Front turn signal lamps 12v 18/5W x2
(front turns are on all the time along with the headlight)
So all up should the bike be using about 70 to 80 watts of power from standard lighting when idling?
Im not sure how much power the engine is using to keep itself going.
Anyone able to figure out from the above specs if it would it be able to keep another 110 watts of lights going without killing the battery quickly with the bike running?
motorbyclist
26th August 2008, 00:30
Alternator ----
Type tri-phase AC
Output 0.32kW/5000rpm
Headlamp 12v 60/55W
Brake lamp 12v 23/8W
Front turn signal lamps 12v 18/5W x2
(front turns are on all the time along with the headlight)
output = 320W
lights = 60+10+40 = 110W
only other stuff is ignition on two cylinders, fan etc approx = 150W (hopefully an overestimate)
excess = 60W (maybe more)
do remember that while the wiring can probably take twice what it's rated for, loading up/overloading your wiring will generate a lot of extra heat which will accelerate the failure rate
cs363
26th August 2008, 00:51
Not just the wiring - wouldn't be too sure how the switches would handle it either over the long term.
Anyway, besides all the above most of those mini spotlights are pretty crap as far as useable light go, if you want increased night vision I'd guess you'd be better off with one good sized decent quality (Hella/Narva etc) driving light.
If you just want to increase your visibility to other traffic go with some proper day riding lights.
toyboy
26th August 2008, 11:18
I got a pair of those cheap mini spotties with the glass lenses from Supercheap auto, they seem pretty bright for mini lights and only mainly want them there for a bit of xtra closeup sideways light and dont really want to shove any major majorly-big spots on the bike, these one seem a perfect size for what there wanted for so it doesnt make the bike look like the front of a big 4wd with blinding spots :)
I'd also be putting in a seperate switch and wire them direct into the battery through a relay so the stock wiring wont be getting overused.
May i could even wire them up so one side spot comes on only when the indicator on its side is indicating, giving me a bit of light to shine around the corner that im turning like some cars do with their extra side lights
cs363
26th August 2008, 11:34
Whatever you do just make sure its legal so you don't run into issues with the cops or at WOF time. Spotlights/driving lights are legally only allowed to work in conjunction with high beam. If you want them on at low beam they will have to have a fog light beam. I doubt that having them working with the indicators would be legal as the bike did not have these as standard.
Probably pay to check with your WOF issuer or LTSA website before you dive in. :)
toyboy
26th August 2008, 12:32
Whatever you do just make sure its legal so you don't run into issues with the cops or at WOF time. Spotlights/driving lights are legally only allowed to work in conjunction with high beam. If you want them on at low beam they will have to have a fog light beam. I doubt that having them working with the indicators would be legal as the bike did not have these as standard.
Probably pay to check with your WOF issuer or LTSA website before you dive in. :)
Easy to just unplug the wire going to the battery for the spotties before the warrant :) Also if their on a separate switch i wouldnt see that being a problem for a WOF as you can turn them on and off independent of anything else (excuse being that their handy if your main bulb blows and you needed a little nighttime illumination in an emergency)
But then again some warrant guys will pick on anything to spoil your day and make themselves feel important.
FJRider
26th August 2008, 12:45
Got a couple of mini 55watt spotties i was thinking of sticking onto the VTR250, will the alternator be able to keep up with the requirements if the main headlight is on as well as the spots?
It would be better to upgrade the bulb (relay probably needed) but I suspect it is not your need of extra light that prompted this question.
toyboy
26th August 2008, 13:04
It would be better to upgrade the bulb (relay probably needed) but I suspect it is not your need of extra light that prompted this question.
Mainly just for a bit of a wider beam of light close up, otherwise I be putting on some 100W highbeam lights to blind the drivers a couple of km away :)
CookMySock
26th August 2008, 13:45
reminder that HID lights only draw 35 watts and put out a massive, massive amount of light. You should not touch the lowbeam headlamp unit, as its required for WOF but they largely do not give a shit about the highbeam.
Steve
toyboy
26th August 2008, 15:58
reminder that HID lights only draw 35 watts and put out a massive, massive amount of light. You should not touch the lowbeam headlamp unit, as its required for WOF but they largely do not give a shit about the highbeam.
Steve
True a single HID would be cool, they do put out a massive amount of light but also cost a massive amount of $$$ :)
If there was a nice single HID kit for $50 it'd be a go (also heard that HID's arnt that great for a single bulb replacement that also requires a high beam as HID take a few seconds to warm up so its not great for quick highbeam flashing? or am i wrong there...)
CookMySock
26th August 2008, 16:27
I bought HID kit for $150 - that did two bikes. There were issues. Search and ye will find.
Steve
tri boy
26th August 2008, 19:22
Any accessory spotlight/flood beam will need to be wired in on H beam circuit.
WOF boys will ping you if you use a seperate switch.
Use voltage from H beam to activate the relay you intend to use with the accessory lights.
Nice n simple.
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