SSSF
Member
I got fed up with discharging my LIPOS at home after crashing my car. It takes hours to do on most LIPO chargers, especially if multiple batteries need to be discharged back to storage voltage.
So i decided to create a circuit that discharges a LIPO.
design principles:
safe:
easy to use:
set cutoff voltage
I created a fully working prototype on a breadboard and now want to go the next step:
create a PCB
The prototype works for 2 and 3 cell Lipo, for 4 cell i need minor adjustments.
I am on holiday and forgot to take pictures to post here . But it also gives me 2 weeks to think about and that's the reason of this post.
Please give your feedback and suggestions to improve.
Please note that I try to keep the components under 20 euro, so not everything is possible.
The current prototype can support up to 3 amps (actually 2 times 1.5) of discharge. I use 100 watt resistors (over specified, but have a nice size) together with radiator and fan to get rid of the heat.
So i decided to create a circuit that discharges a LIPO.
design principles:
- safe
- easy to use
- set cutoff voltage
safe:
- 2 ways to stop discharge, one to set normal stop voltage, one safety voltage
- a fuse to protect against short-circuit
- design that a failing component never leads to over discharge
easy to use:
- be able to set stop voltage
- start and forget: the device will be completely disconnected from LIPO when discharge is completed. So it will not discharge any further (means zero load). You can keep it connected forever without further discharging.
- discharge cycle has acceptabele time
set cutoff voltage
- the voltage when discharge is stopped can be set between 3 and 3.8 volt
I created a fully working prototype on a breadboard and now want to go the next step:
create a PCB
The prototype works for 2 and 3 cell Lipo, for 4 cell i need minor adjustments.
I am on holiday and forgot to take pictures to post here . But it also gives me 2 weeks to think about and that's the reason of this post.
Please give your feedback and suggestions to improve.
Please note that I try to keep the components under 20 euro, so not everything is possible.
The current prototype can support up to 3 amps (actually 2 times 1.5) of discharge. I use 100 watt resistors (over specified, but have a nice size) together with radiator and fan to get rid of the heat.