[Off grid system]
Everything was working fine. MPP Solar 2424, 650 watts of panels...no problems.
Connected an a.c. battery charger to charge an electric lawnmower battery, came up ok. A few minutes later, everything dead. No signs of life on the MPP Solar. Confirmed that the a.c. charger worked fine on grid power.
Incoming power from the array fine. Ambient temperature around 75 degrees F.
Here's the very odd thing: Checked battery voltage, read 34 volts. WAY too high of course. MPP Solar was set to absorb at 28 volts and float at 27, never saw voltage above 28 on MPP Solar LCD. Checked battery voltage again, only a couple minutes later....ZER0, nothing, nada.
So it appears the BMS shut the battery down...but why? And what can I do?
If I open battery to check cell voltages will I void the warantee? But isn't that the only way to determine if it's a failed BMS?
Please help!
Thank you.
Problem solved:
*Opened battery, read voltage directly (23.2), bypassing BMS, thus confirming that BMS had kicked in due low voltage
*Ran heavy duty test lead from internal Neg post to external Neg post, bypassing BMS
*Opened breaker to the array, closed battery breaker
*Charger woke up
*Closed breaker to array
*Charging began
*Disconnected Neg - Neg test lead
Post-event analysis:
I had set Bulk/Absorb too low (27v) and had a few very overcast days. Hooking up the lawnmower battery charger must have pulled the battery below the BMS cutoff point. The 34 volt reading is still unexplained, assuming it was spurious.