I've tried Googling but I can't find a answer. Is there a recommended cut off voltage I should set on my ebike firmware for an NCR1860GA 14S 5P battery? I have the TSDZ2 Open Source firmware and it needs to be configured with a minimum voltage. The Wiki suggests 42v, but I'm pretty sure the original factory firmware had the cut off voltage set much higher, as the bike would switch off when the battery fuel guage was still on two bars, whereas now I'm on one bar (the red bar) and the firmware still hasn't shut the motor off.
What should I set min discharge voltage for NCR1860GA 14S battery?
- Thread starter rcx194
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It needs to balance
your desire to get maximum range, at the expense of pack lifespan
and how much your "normal / desired" usage, peak C-rate, draws voltage sage down temporarily
I would start higher than you think, and tweak it downward as needed, leaving it as high as you can stand it.
As the pack ages, you will likely need to keep adjusting down.
your desire to get maximum range, at the expense of pack lifespan
and how much your "normal / desired" usage, peak C-rate, draws voltage sage down temporarily
I would start higher than you think, and tweak it downward as needed, leaving it as high as you can stand it.
As the pack ages, you will likely need to keep adjusting down.
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42 Volts LVC is 3.0 Volts per cell under load. Should be safe as pack will rebound to maybe 3.2 or 3.3 Volts Per Cell at rest depending on how much of a load you are placing on the cells at the time of LVC. But if it were me, I'd use 44 Volts to be kinder to the cells as long as you're getting the range you want.
Start at 3.4V even 3.5V
but if you need to go WOT on amps that will cut you off way too early, GA are not exactly supercells.
If you end up down at 3.2 or even 3.1 no worries, just the more you leave in there per average cycle the greater your number of cycles lifespan, by a lot.
but if you need to go WOT on amps that will cut you off way too early, GA are not exactly supercells.
If you end up down at 3.2 or even 3.1 no worries, just the more you leave in there per average cycle the greater your number of cycles lifespan, by a lot.
Oki, I'm set to 44v at the moment, I don't mind moving to 3.5v per series (49v). By the way I've noticed that the battery pack itself cuts off at 44v.
When I asked the shop how the pack was configured they said it was set to charge to 100% and discharge to 20%. I hoped to set it to charge to 80% (80/20 rule) so I looked up the BMS and contacted the manufacturer in China, in hope that I could buy a cable to re-program it. But language barrier got in the way. From what I could understand it doesn't sound like the BMS can be re-programmed.
When I asked the shop how the pack was configured they said it was set to charge to 100% and discharge to 20%. I hoped to set it to charge to 80% (80/20 rule) so I looked up the BMS and contacted the manufacturer in China, in hope that I could buy a cable to re-program it. But language barrier got in the way. From what I could understand it doesn't sound like the BMS can be re-programmed.
Some BMS are more trustworthy than others.
Some users are more trusting than others.
I would for example use an Orion BMS to control an Elcon charger, the failsafe mechanism is built into their CAN protocol.
But if I were to use a lesser BMS to do the same, say with a contactor on the PSU's input
I would still have a redundant HVC for when (not if) the primary regulation fails.
Consequence of my house burning down, worth putting in belt and suspenders.
Some users are more trusting than others.
I would for example use an Orion BMS to control an Elcon charger, the failsafe mechanism is built into their CAN protocol.
But if I were to use a lesser BMS to do the same, say with a contactor on the PSU's input
I would still have a redundant HVC for when (not if) the primary regulation fails.
Consequence of my house burning down, worth putting in belt and suspenders.
rcx194 said:
That is correct, in typical ebike packs the BMS does this. The charger just outputs until the BMS shuts off due to cell-level HVC/etc. (some chargers will shut off once current drops below a certain point, some don't).
There may be advanced systems in large EVs that are different--but the stuff you're using is not.
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