Merlin said:mh....my BMS is set for 3.2v (lvc) because its only for emergency (cut off) for me.
that a RC charger is different i know. thats why i asked "why" adapttos doesnt do it in the same way since it knows all cell voltages
do you charge through the controller? with a coil or with a 82v charger?
Merlin said:maybe its why you dont use a bms.
i dont like that it starts hundred times again and again instead of lowering charge amps.
brumbrum said:have i missed something here. , because as far as my charging is concerned (using the adaptto bms system) it does not matter what you set max battery pack charge voltage or HVC to, these are ignored and it is only the individual cell settings that determine the charge process.
I found that by setting the BALANCING voltage of the cells HIGHER(4.16 as example) and MAXIMUM cell voltage LOWER (4.13 as example) then the first cell to reach 4.13 gets bled off much quicker to pull up the other cells rather than having the balance at a lower value which takes forever. The charger automatically flicks between balance and charge mode so you get intermittent amps being pumped into the pack as well as intermittent bleeding of the top runnaway cell.
The weird thing is the lights on the bms board do not light up when doing it this way.... But it works.
I have alao found that i need to have both the hvc AND the max(pack)voltage cutoff settings set slightly higher for regen to work from a fully charged pack (in other words not just the hvc setting).
But again, these are just my observations...
brumbrum said:If i charge/balance like you do, yes the bms lights flash and the bms unit gets warm.
If i charge/balance like i have stated above, the lights do not switch on and off and the bms stays cold. I checked to see also if the balance tap leads get warm(just incase) but they stay cold too. I have found that in the first 30 to 60 minutes(as long as the highest cell is say 4.10 or higher) it initially bleeds off much quicker and the overall differnces between highest and lowest cells decreases.
GmagNeato said:brumbrum said:If i charge/balance like you do, yes the bms lights flash and the bms unit gets warm.
If i charge/balance like i have stated above, the lights do not switch on and off and the bms stays cold. I checked to see also if the balance tap leads get warm(just incase) but they stay cold too. I have found that in the first 30 to 60 minutes(as long as the highest cell is say 4.10 or higher) it initially bleeds off much quicker and the overall differnces between highest and lowest cells decreases.
The more I think of this the less I understand it. It appears that your BMS is not activating at all. Which would make sense because the Balancing voltage you have set is not being reached and therefore should not be triggering the BMS to begin balancing. So I wonder what is balancing your pack? Or what is bleeding down the first cells to hit your specified max cell voltage?
Allex said:Yes, this is how it works, shuts of the charge when it reaches the set voltage and starts again with small current(bout 0,5-3A and not 30A like in your case) when the BMS did a bit of bleed.
A hobby charger does the same(at least my hyperion) it stops the charge once a cell hits 4.2 - bleed it down and slowly charge the others.
Merlin said:i dont get it how it could be work when i setup 4.20v cell max and maybe 4.19v balance voltage.
the charger will try to reach 4.20(84v)
the bms wants to bleed the cells down to 4.19 (83,8v)
the charger see: oh battery has only 83,8v...and start to charge again.
this game goes on till i stop the charge....
GmagNeato said:@Brum might have an issue with channel 1 cell. Could be going up in voltage quickly due to reduced capacity. Then when the charge current stops it comes down quickly to meet the others due to high self discharge. May want to check the internal resistance and overall health on that one. Is it in an older pack?
Also wanted to say that with firmware 9G2 my BMS continues to balance after the charger has completely charged the battery and I've unplugged the charger from the wall. I'm assuming it will do so until the top cell reaches the BMS balance voltage I've got set? Nice that it just quietly continues to balance until I go for a ride and bring the voltage down. I've left it this way for about 2 hours now and the delta has gone from .021 to .018. I hope this function hasn't changed on 9G4 which I'll be flashing to once my SD card arrives tomorrow.
brumbrum said:GmagNeato said:@Brum might have an issue with channel 1 cell. Could be going up in voltage quickly due to reduced capacity. Then when the charge current stops it comes down quickly to meet the others due to high self discharge. May want to check the internal resistance and overall health on that one. Is it in an older pack?
Also wanted to say that with firmware 9G2 my BMS continues to balance after the charger has completely charged the battery and I've unplugged the charger from the wall. I'm assuming it will do so until the top cell reaches the BMS balance voltage I've got set? Nice that it just quietly continues to balance until I go for a ride and bring the voltage down. I've left it this way for about 2 hours now and the delta has gone from .021 to .018. I hope this function hasn't changed on 9G4 which I'll be flashing to once my SD card arrives tomorrow.
Thanks for the heads up, the cells are actually pretty new, so i will keep an eye on things.
What do you mean when you mention 'delta' , is this a term for the cell voltage difference or is it a measurement for something else that i can find in my adaptto display?
madin88 said:Merlin said:i dont get it how it could be work when i setup 4.20v cell max and maybe 4.19v balance voltage.
the charger will try to reach 4.20(84v)
the bms wants to bleed the cells down to 4.19 (83,8v)
the charger see: oh battery has only 83,8v...and start to charge again.
this game goes on till i stop the charge....
if you set balancing voltage to lets say 4,00V, it only means the BMS will START to eneable the balancing at this voltage, but it should not bleed the cells down to 4,00V
the lower the value, the sooner the pack will be equalized.
RC chargers normally do balancing from the beginning on.
Merlin said:Hello,
it is absolutely right, one circuit breaker is sufficient.
NO NO NO
if you use one C63 breaker at 200A, it could be that it takes 1min or only 10sec until it breakes the connection
(they work with a bimetal cut off)
However we faced an increasing number of controller failures because of faulty or incorrectly operating breakers recently.
Considering this it is worth installing two circuit breakers (of different brands if possible) in order to ensure more protection.
Best regards,
and if you go with 2, use them in series, not parallel![]()
Merlin said:hmm,
all my RC Chargers have the option where to start balancing.
default out of the box a junsi 4010 starts at 4,0v with balancing.
i have understand and tested, if i setup balance voltage to 4.0 in the adaptto bms, it starts on 4.0v
BUT
it DOES bleed the cells down to that set voltage.