Im working on a board for controlling a few linear actuators. They will at full load draw something like 10A, and will be powered by a 24V (or so) LiPo pack.
I have a few H-bridges and as expected when the power is cut off, there is an inductive kickback of about 10A. No PWM, they will be turned on and off occasionally only.
I havent been able to fibd anything on if a LiPo pack would be able to take this reverse current, or if it needs some sort of protection. It also lasts for quite a short time but I’m new to batteries so I want to be sure its not a problem.
Would apprecaite any help :)
eceforge@discuss.tchncs.de 2 days ago
So your Lipo pack will have a max charging voltage that you can apply to it. If your voltage at the pack spikes to above that max charging voltage then that’s bad. The pack should also have a max charging current, try to stay under that as well. So long as you stay within those bounds, reverse current is just free charging of the battery.
Almost always though an inductive kick from something that draws 10A is going to go way higher than the pack max charge voltage for just long enough to be a problem to the rest of the electronics. It’s very common practice to put a kick-back protection diode for this reason (basically just a diode wired at the output of the bridge in parallel with the load that is oriented to not conduct during the time that you provide power to the load).
You could also put a tvs protection diode there with a breakdown voltage just under the problematic voltage, so long as it’s rated to handle the energy.
quiescentcurrent@discuss.tchncs.de 2 days ago
I was just typing out my reply, but yours is much more detailed anyway, @OP this is the correct solution.