Sparfuchs
1 kW
- Joined
- Nov 22, 2020
- Messages
- 305
Hello EV friends,
thanks to all your help in my thread "Sabvoton SVMC 72150 doesn't do full power" (link below),we/I now think that the most plausible problem is, that the Sabvoton SVMC 72150 has a "protection" that limits the current if the voltage drop gets to a (unknown) value that can't be changed. So no, not talking about "Current Limiting Voltage" or "Lack Voltage"
As I wanna get more than just 100A for a few ms I'm looking for a way to reduce the voltage drop (regardless of the voltage drop in the battery itself) between my 19s4p Samsung 21700 40T battery pack and the sabvoton at max. loads of up to 200 amps (always just for a few second bursts) and have thought of using one or more capacitors and if necessary diodes between the battery and the controller, to pretend/give the controller stable voltage... or do you have any other ideas?
More precisely: I built a battery pack from 19 serial and 4 parallel connected Samsung 40T 21700 lithium-ion cells that theoretically could handle short-term pulse currents of up to 280 amperes (70A per cell) and a continuous discharge of 100A (even 180A with temp. monitoring). What you could expect is that the voltage drops under load (specifically by about 10v at 100A discharge in my case).
But what I didn't expect is that the controller seems to have a protection that limits the maximum current at a certain voltage drop (much earlier than necessary). Since this cannot be changed in the software and it seems too complex to me to access the firmware, I had the consideration with the capacitors/diodes.
I'm not sure how it behaves with the simultaneous/alternating charging and discharging of the capacitor, but I am considering a strong diode might be required in my 8AWG wire to avoid equalizing currents (the battery can be charged with max. 24A) between the capacitor and the battery, which shouldn't increase my resistance much.
It should also be mentioned that the same wire is used for charging and discharging, which usually happens very quickly and alternately through regenerative braking.
I'm not that well versed in terms of potential, but I wonder if equalizing currents occur at all if the capacitor for charging has a lower potential to the battery, and as soon as the voltage of the bat. suddenly drops due to heavy consumption and it's potential increases, probably the lowest potential should be to the consumer/controller and not to the battery, which means that the capacitor discharge only takes place in one direction (cap. to controller) anyway?
Unfortunately, I don't have the know-how, which components are available and whether/how my idea can be implemented... or whether there is even a better solution and I would be very grateful for your ideas !
Thanks for your Help
Best regards
Sparfuchs
Sabvoton SVMC 72150 doesn't do full power: ://endless-sphere.com/forums/viewtopic.php?f=30&t=118808
thanks to all your help in my thread "Sabvoton SVMC 72150 doesn't do full power" (link below),we/I now think that the most plausible problem is, that the Sabvoton SVMC 72150 has a "protection" that limits the current if the voltage drop gets to a (unknown) value that can't be changed. So no, not talking about "Current Limiting Voltage" or "Lack Voltage"
As I wanna get more than just 100A for a few ms I'm looking for a way to reduce the voltage drop (regardless of the voltage drop in the battery itself) between my 19s4p Samsung 21700 40T battery pack and the sabvoton at max. loads of up to 200 amps (always just for a few second bursts) and have thought of using one or more capacitors and if necessary diodes between the battery and the controller, to pretend/give the controller stable voltage... or do you have any other ideas?
More precisely: I built a battery pack from 19 serial and 4 parallel connected Samsung 40T 21700 lithium-ion cells that theoretically could handle short-term pulse currents of up to 280 amperes (70A per cell) and a continuous discharge of 100A (even 180A with temp. monitoring). What you could expect is that the voltage drops under load (specifically by about 10v at 100A discharge in my case).
But what I didn't expect is that the controller seems to have a protection that limits the maximum current at a certain voltage drop (much earlier than necessary). Since this cannot be changed in the software and it seems too complex to me to access the firmware, I had the consideration with the capacitors/diodes.
I'm not sure how it behaves with the simultaneous/alternating charging and discharging of the capacitor, but I am considering a strong diode might be required in my 8AWG wire to avoid equalizing currents (the battery can be charged with max. 24A) between the capacitor and the battery, which shouldn't increase my resistance much.
It should also be mentioned that the same wire is used for charging and discharging, which usually happens very quickly and alternately through regenerative braking.
I'm not that well versed in terms of potential, but I wonder if equalizing currents occur at all if the capacitor for charging has a lower potential to the battery, and as soon as the voltage of the bat. suddenly drops due to heavy consumption and it's potential increases, probably the lowest potential should be to the consumer/controller and not to the battery, which means that the capacitor discharge only takes place in one direction (cap. to controller) anyway?
Unfortunately, I don't have the know-how, which components are available and whether/how my idea can be implemented... or whether there is even a better solution and I would be very grateful for your ideas !
Thanks for your Help
Best regards
Sparfuchs
Sabvoton SVMC 72150 doesn't do full power: ://endless-sphere.com/forums/viewtopic.php?f=30&t=118808