Frey EX - New Battery capacity issue

[2Slow]

Guys, I got 3A charger supplied with Frey EX. Checked output current, it's under 3A. Battery goes from 5% to 100% in 3 hours. Meaning it's accepted about 9 a/h of charge. But spec suggest 14a/h batteries. Max voltage suggest they are 100% charged to 4.2V, so no buffer at the top. I hear that there is some buffer at the bottom below 3.7V
Did anyone ever put battery thru capacity test? At face value, they appear overrated by 30%.
Same performance observed for in-tube and external battery.

 

[dfrydman]

what was the voltage of the battery when you started charging because discharging a battery 95% will shorten battery life significantly (shouldnt discharge past 80%) so maybe the batery was that dead.

is it a smart charger? because smart chargers change their output depending on which phase of charging you're at (usually at the end current satrts dropping steadily) so try to test current while the charger is charging the battery if you havent done so already

 

[amberwolf]

what was the voltage of the battery when you started charging because discharging a battery 95% will shorten battery life significantly (shouldnt discharge past 80%) so maybe the batery was that dead.

If that was an SLA battery, that would be true. (though with SLA, I'd say 50% is a much better limit).

The BMS and controller are there to prevent this in Lithium batteries like that used in this pack, and Lithium batteries don't behave like SLA, anyway.

 

[2Slow]

I will cycle batteries around 10 times and then datalog charging curves in order to get better idea on what's going on.
Max voltage of charged batteries now sit at 54.4V by memory.
Also, it's interesting that Frey's dual battery system charges in-tube battery first, and only after it's charged charges external battery. I did not expect that, assuming both batteries will charge in parallel.
I prefer parallel charging, as I like to charge them at lower power input, extends lifespan.

 

[amberwolf]

I like to charge them at lower power input, extends lifespan.

You can still do that, just use a lower-current charger, or adjust the current of the one you have if it has that option.