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Shorai battery - reduced charging Volts?
Posted: Fri Jul 09, 2021 1:49 pm
by dcarver
Installed Shorai battery on 2006 Gen2, KrZy8.
Immediately noticed decreased max volts on voltmeter.
AGM battery always 14.1 to 14.3, base load.
Shorai immediately dropped to 13.7 -13.9, same base load and ambient temps.
Even substituted AGM battery for Shorai, and yep, back to 14.1 to 14.3.
Base research shows that *some* Li batteries (for motor homes, other bigger applications) have a circuit internal to Li battery which effectively disconnects RR output to keep volts in the Li battery 'sweet' (lower) regions.
Any ideas oh great FJR pundits?
Re: Shorai battery - reduced charging Volts?
Posted: Fri Jul 09, 2021 1:58 pm
by ionbeam
dcarver wrote: ↑Fri Jul 09, 2021 1:49 pm
Installed Shorai battery on 2006 Gen2, KrZy8.
Immediately noticed decreased max volts on voltmeter.
AGM battery always 14.1 to 14.3, base load.
Shorai immediately dropped to 13.7 -13.9, same base load and ambient temps...
This was with a fully charged Shorai battery?
Re: Shorai battery - reduced charging Volts?
Posted: Fri Jul 09, 2021 4:06 pm
by N4HHE
dcarver wrote: ↑Fri Jul 09, 2021 1:49 pm
Base research shows that *some* Li batteries (for motor homes, other bigger applications) have a circuit internal to Li battery which effectively disconnects RR output to keep volts in the Li battery 'sweet' (lower) regions.
Any ideas oh great FJR pundits?
It can not be that the internal BCM disconnects "to keep volts lower". If it did then the R/R voltage would rise to its nominal 14.2V for lack of load.
For the R/R to be held down to 13.8 the Shorai must be loading the circuit. The 0.4V must be going to heat somewhere in the battery.
No matter, 13.8v is a good healthy fully charged lead-acid voltage. Worry more about the engine off voltage.
Re: Shorai battery - reduced charging Volts?
Posted: Fri Jul 09, 2021 5:40 pm
by dcarver
ionbeam wrote: ↑Fri Jul 09, 2021 1:58 pm
dcarver wrote: ↑Fri Jul 09, 2021 1:49 pm
Installed Shorai battery on 2006 Gen2, KrZy8.
Immediately noticed decreased max volts on voltmeter.
AGM battery always 14.1 to 14.3, base load.
Shorai immediately dropped to 13.7 -13.9, same base load and ambient temps...
This was with a fully charged Shorai battery?
Yes, fully charged with appropriate Li battery charger. Good point, I forgot to mention it.
Re: Shorai battery - reduced charging Volts?
Posted: Fri Jul 09, 2021 6:13 pm
by dcarver
N4HHE wrote: ↑Fri Jul 09, 2021 4:06 pm
dcarver wrote: ↑Fri Jul 09, 2021 1:49 pm
Base research shows that *some* Li batteries (for motor homes, other bigger applications) have a circuit internal to Li battery which effectively disconnects RR output to keep volts in the Li battery 'sweet' (lower) regions.
Any ideas oh great FJR pundits?
It can not be that the internal BCM disconnects "to keep volts lower". If it did then the R/R voltage would rise to its nominal 14.2V for lack of load.
For the R/R to be held down to 13.8 the Shorai must be loading the circuit. The 0.4V must be going to heat somewhere in the battery.
No matter, 13.8v is a good healthy fully charged lead-acid voltage. Worry more about the engine off voltage.
Agreed 13.8 is good, just used to seeing 14.x all the time. Install Li and boom, down to 13.8, got me curious.
I do see that RMSTATOR and RicksMotorSports
https://ricksmotorsportelectrics.com/Re ... le-14_420 make Li specific RR to reduce charging volts to Li batteries.
Just for grins and giggles, I'm going to install a new to me from RoadsterCycle RR on the 06 and see what happens. Will also measure ACV from stator to ensure all is healthy there.
Re: Shorai battery - reduced charging Volts?
Posted: Fri Jul 09, 2021 6:27 pm
by dcarver
dcarver wrote: ↑Fri Jul 09, 2021 5:40 pm
ionbeam wrote: ↑Fri Jul 09, 2021 1:58 pm
dcarver wrote: ↑Fri Jul 09, 2021 1:49 pm
Installed Shorai battery on 2006 Gen2, KrZy8.
Immediately noticed decreased max volts on voltmeter.
AGM battery always 14.1 to 14.3, base load.
Shorai immediately dropped to 13.7 -13.9, same base load and ambient temps...
This was with a fully charged Shorai battery?
Yes, fully charged with appropriate Li battery charger. Good point, I forgot to mention it. Also have 300 plus miles of riding too.