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Alternator Charging Question...

Started by Tor-King, March 25, 2017, 05:27:54 PM

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Pat Conlon

I agree with you Dean.
Conventional lead acid wet cell batteries can tolerate  the 15+ charging voltage, you just add water.

AGM's on the other hand, can not tolerate voltage that high. All the manufacturers specifications I've read state to limit the charging voltage to 14.4 volts maximum.
I am not a fan of the FJ oem voltage regulator.
IMHO the adjustable Transpo VR is a necessary mod, if you want to run AGM batteries.

You guys have got to ask yourselves : Why?
Why is the red plug melting?  

It's the oem voltage regulator going crazy. What causes this? Is it engine heat? Is it vibrations?
Dunno, but all my charging issues went away when I installed the out board (isolated from heat/vibrations) Transpo VR..... and my light bulbs last longer.
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

ribbert

Quote from: Tor-King on March 28, 2017, 08:31:33 PM
..................  It jumped up to 15.1v at one time. Will this cook the battery with the generator cranking out these volts?  According to Clymers it is within specs for it to be charging up to 15.3v, but I feel that that is on the high side?  Opinions?

Thanks,
Dean

My bike always starts off at 15.1 for a while then settles down. I have had an AGM battery for years. No problem.
The charge rate after starting is always going to be higher but settles down after a while. My red connector is original (as is my regulator) and still in good shape after a lot of miles at that charging rate.
If riding any distance, you will notice it likely drops down into the 12's after a while.

IMO

Noel
"Tell a wise man something he doesn't know and he'll thank you, tell a fool something he doesn't know and he'll abuse you"