Something got cooked while on batt charger

[ddominik]

Background:
I have a nice '77 GS750C which is my "daily ride". It has an intermittent trickle short which I was planning on chasing down this winter. By intermittent I mean sometimes it sits for a week and the battery is fine (still at full charge) other times it sits for a few days and the battery is down (headlight very dim) .... verified with multimeter. Thank God for kick starers!!!!

Problem:
Last week was a "low battery week", so I put the charger on a 10 amp charge overnight. The next morning the garage was filled with this electrical ozone smell and the GS750 did not respond electrically when I turned the key on. A check of the battery showed it at full change, about 13.6 volts, but in the GS electrical system I suspect something got cooked. Before I tear into this problem I welcome any and all opinions as to the possible culprit.

My question is .... in what order should I start my diagnosis? Obviously I'll start with verifying continuity across the the key ... but then what?

Thanks in advance to all you gangsters ... you've already helped me various time through your many treads and now I could use you help as I'm a mechanical guy .... electrical stuff just isn't my strength.

Dom
Bloomington Spring, TN

[tom203]

Well, you just found out why I disconnect the negative battery cable when I charge a small battery like this. A 10 amp charger is way too much to leave on overnight- a 2 amp rate is much safer. Chances are your battery voltage climbed to > 16 volts depending on quality of charger circuit. Look for fried wires , maybe in rectifier/ regulator area. Also, check fluid level in battery- it may have boiled off.

[raistian77]

Dang, sorry to hear that. It sounds like what ever has been leaking the current failed completely. Like Tom stated big chargers tend to float the voltage very high. Grab a wiring diagram from Basscliffs website and start at the battery working you're way out till you find where you are loosing power. I would be prepared to replace the R/R and battery (these small batteries cant handle 16+volts for very long. When you get it solved get a SMALL fully automatic motorcycle battery charger. When I charge my battery I pull my main fuse, The R/R probably tried to regulate the voltage smoking it in the process.

[raistian77]

I might be able to help you, you are only 2 hours away from me

[tas850g]

It doesn't sound like your electrical gremlin is at fault in this example. I think you OVERCHARGED the battery. As Tom stated should never charge a batter at 10amps for such a long time. Sounds like now you have to go through your wiring harness to check and fix any fried wires to get you back to your initial starting point, finding your trickle discharge.

[ddominik]

Thanks for the offer raistian77
I'll do a quick check on the r/r (stator papers) ... if it goes beyond that it become a winter project and I will probably need some help. I'll pm you.

Thanks again to all

BTW the battery is OK