Triumphrat

ohiorider · 03-20-2008

I'm not sure where I found this info, but if it is accurate, I thought it might be useful for all these northern bikes that are about to come out of storage, and be started up for the first time in weeks. It might save forum members from jumping through hoops when the problem is simply a low battery. The chart provides %age of charge info for both 12 and 6 volt batteries. It's an easy thing to ck with a multimeter. Excuse the formatting, or lack of.

Approximate charge ----- Relative acid density
12.65 V 6.3 V 100% 1.265
12.45 V 6.2 V 75% 1.225
12.24 V 6.1 V 50% 1.190
12.06 V 6.0 V 25% 1.155
11.89 V 6.0 V 0% 1.120

Bob

jbfla · 03-20-2008

I thought I read that 10.5v on a 12v battery was considered dead...but I've been wrong many times before.

jb

357Bob · 03-20-2008

When you do a load test on an automotive lead acid battery you load it down to 10.5 volts while watching for the proper amps. I would assume (ass-u-me) any lead acid battery would be the same just less amperage for the smaller ones. But "dead" would only be relative to what you wanted the battery to do. It might be dead as far as starting a cold engine but might start a warm engine. But yes 10.5 volts is close to dead. At least it is recharge time for sure.

mikeinva · 03-20-2008

that chart looks about right we use to check battery with a hydrometer ( how ever you spell it lol) that was back before load testers came out.load tester will show you a bad battery real quick.If you have had your battery on a small charger(2amp slow charge) and you run a load test and it dies better get a new one .

ohiorider · 03-20-2008

Help me out here. Is a load tester a device that lets you add more and more load until you're down to 10.5V, at which point you measure the amps? Sorry, but I'm much more comfortable with jets, brakes, valves, etc, than with the electrical.

Bob

jbfla · 03-21-2008

This is the load tester I use on car/boat batteries.

http://www.harborfreight.com/cpi/cta...emnumber=93784

Connect the meter to the battery terminals.
Hold down the switch for 10 seconds (runs battery current through heavy wires).
Needle on meter indicates if battery is good or not.

Kind of a load tester for dummies...

It doesn't indicate amps.

I haven't used it on a motorcycle battery... since bike batteries have much less capacity than car batteries (and there isn't an amp meter), I was afraid it might kill the smaller battery.

Advice from those more informed would be appreciated.

jb

jfenton · 03-21-2008

Yes, you might want to be carefull what type of load tester you use on your motorcycle battery, since it has much smaller capacity than a car battery.

If the load tester is a fixed resistance type, then it will draw the same current from your car battery and motorcycle battery, which could be a bad day for your motorcycle battery.

If it is a smarter one that loads it down until the voltage gets to say 10.5V and keeps it there, this is a variable resistance style, which should not harm any battery and will check it properly.

ohiorider · 03-21-2008

To all - Thanks for the good info. This thread gets copied, pasted, and filed in my Triumph folder under 'electrical stuff'.

Bob

jbfla · 03-21-2008

jfenton, thanks for confirming my suspicions on the unregulated load tester.

I found this load tester that says it has an adjustable load from 0 to 500 amps.

http://www.harborfreight.com/cpi/cta...emnumber=91129

Might have to give it a try.

jb

mikeinva · 03-21-2008

you want one you can adj the load.the way you use it you increase the load till it drops then you see if the amp load is what the battery is rated at.