News:

           Enjoy your FJ


Main Menu

3CV charging query

Started by ELIMINATOR, March 17, 2012, 02:15:34 AM

Previous topic - Next topic

ELIMINATOR

I looked at the battery fluid level yesterday, I had to top the battery up. I topped it up about .............. hmm, a while ago I guess, might have been 3,000 miles / 6 months ago.
This seems a bit excessive to me. I started her up, connected a voltmeter, revved to over 5,000 volts went up to 14.7, which from what I've read on the subject is within limit. Is it down to the fact that the FJ is a very hot running bike, and it soaks through to the battery leading to evaporation of the distilled water?


http://www.offwidth.co.uk/bike/general/electrical_fault_finding_2.pdf

The blurb with the above says that it only works if the bike has a combined regulator & rectifier in one case, so does this apply to the FJ?   
BMW 1150GS
Moto Guzzi California 3

terryk

Quote from: ELIMINATOR on March 17, 2012, 02:15:34 AM
I looked at the battery fluid level yesterday, I had to top the battery up. I topped it up about .............. hmm, a while ago I guess, might have been 3,000 miles / 6 months ago.
This seems a bit excessive to me. I started her up, connected a voltmeter, revved to over 5,000 volts went up to 14.7, which from what I've read on the subject is within limit. Is it down to the fact that the FJ is a very hot running bike, and it soaks through to the battery leading to evaporation of the distilled water?


http://www.offwidth.co.uk/bike/general/electrical_fault_finding_2.pdf

The blurb with the above says that it only works if the bike has a combined regulator & rectifier in one case, so does this apply to the FJ?   

1) The Absorbed Glass Mat battery techniolgy is up to the task of enduring the FJ charging system issues. No boil off of battery acid. You can go for a more expensive solution, the new fangled Nanophosphate Lithium Technology or the like but this is expensive although light. I say go with AGM and take a good dump before riding. 2) I had the hot starting issues. I can not say this enough, RPM's starter motor rocks. I took a good long ride yesterday and normally I would have expected a total hope and pray will it restart when hot experience. Push starter button, rrrr and slow turnover of engine, stops and nothing. rrrr, slow and maybe a catch. New starter = instant and total cranking, power man, better than you could imagine.

Pat Conlon

Something happens to the FJ's voltage regulator when riding. Heat? Vibration? Dunno, but it goes wacky and puts out 15 plus volts to the battery.
You can bench test all day long and not find the overcharging, only on the road does it happen.
Relocating the regulator away from the engine heat/vibration solves the problem. The Transpo voltage regulator mod works for me.
AGM's do not tolerate overcharging as well as lead acid. The mfgr's specs I've seen caution a maximum charging voltage of 14.4 volts.

Do not install a AGM and think you have solved your problem. Do the Transpo mod.  Cheers. Pat
1) Free Owners Manual download: https://tinyurl.com/fmsz7hk9
2) Don't store your FJ with E10 fuel https://tinyurl.com/3cjrfct5
3) Replace your old stock rubber brake lines.
4) Important items for the '84-87 FJ's:
Safety wire: https://tinyurl.com/99zp8ufh
Fuel line: https://tinyurl.com/bdff9bf3

WhiteBeard


racerrad8

Here is another option for the regulator; Regulator

P.S. - Did someone say Battery?

Randy - RPM




Sorry, I just could not resist... :biggrin:
Randy - RPM