webosplash
10 mW
- Joined
- Feb 14, 2021
- Messages
- 22
probably 0.oflippy said:probably. just make sure the voltages match within 1V before connecting them up.
If enclosed and non-removable, this would be ideal.john61ct said:Yes, but I would wire each of the cell / balance points in parallel too, not just pack level power.
One good BMS to monitor / protect the lot
if any
goatman said:80 amp controller
20s10p 80 amp bms
20s10p 100 amp bms
full out 80amps from 20p is only 4amps/cel
unless youre running recycled laptop cells, who cares, just parallel the batteries together
what cells do you have?
goatman said:i would, theyre both "10amp" cells with the same rated capacity being discharged at 4amps max
unles youre hopping on the highway and going full throttle til the lvc is tripped, dont see a problem
go to the lygte comparator here
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
put in the cells with 2amp discharge and 5amp discharge, they both hit what would be the lvc at about the same time with very similar discharge curves
goatman said:so do i
its just if your full throttle and 1 bms trips its lvc the other will go from 40amps discharge to 80amps discharge at the same moment, could be a problem for a crappy bms
Both batteries are 35AH 72V the only difference is one is capable of 100A and the other is capable of 80ARobinev said:Ideally you should use same cells with same amp hour capacities throughout a battery pack. they should all be balanced to +\- .02 volts per cell prior to a series and or parallel connection. Any discrepancy in voltage can set a battery into a thermal run away in some cases the heat will trigger the next cell to start thermal sprinting. Batteries don t like being used unbalanced. Or with other batteries that have less capacity. Especially batteries that get super hot. Worst case scenario the weakest link in the chain will give. Lmk how it goes. If it goes up in flames [emoji91] try and put it out fast needless to say don’t kill anyone including yourself. Last thing we need is more legislations for dangerous batteries builders
[emoji367].
Paralleled connections will never flow perfectly evenlywebosplash said:Both batteries are 35AH 72V the only difference is one is capable of 100A and the other is capable of 80ARobinev said:Ideally you should use same cells with same amp hour capacities throughout a battery pack. they should all be balanced to +\- .02 volts per cell prior to a series and or parallel connection. Any discrepancy in voltage can set a battery into a thermal run away in some cases the heat will trigger the next cell to start thermal sprinting. Batteries don t like being used unbalanced. Or with other batteries that have less capacity. Especially batteries that get super hot. Worst case scenario the weakest link in the chain will give. Lmk how it goes. If it goes up in flames [emoji91] try and put it out fast needless to say don’t kill anyone including yourself. Last thing we need is more legislations for dangerous batteries builders
[emoji367].
If the parallel connection is trying to draw 80A would that demand 40A from each pack or would the controller try to draw more from the 100A pack.
This is the answer I need.
webosplash said:but will the controller demand 40 from each battery or will the controller recognize that one can drain faster and do so?