50+kWh of drone batteries
Posted: Wed Jun 01, 2022 7:28 pm
Hi,
I've acquired 500ish 4S drone batteries made by ATL from a drone company I used to work for. Most of them are new, but datecode goes back a few years, so there is some degradation from storage.
They should be rated 6800ish mAh, but are mostly 6000mAh. They are HV, cells are supposed to charge up to 4.35V and there are FPC heaters between the cells. Each pack can safely deliver 15-20A of current. Think of modern DJI drone batteries, but for a different ODM project. My plan is to get rid of the plastic enclosure and current BMS and make modules of 4S10P or 4S20P and then rig them in to something bigger as needed. Do trivial monitoring/balancing with custom pcb per 4S10P pack, which would serve as an internal bus bar as well.
I'm an electrical engineer with (hopefully) enough mechanical engineering skills and I have done ICE engine swaps previously so I am aware on how deep the rabbit hole will go.
I've thought about making a powerwall, but that's no fun. Given that batteries are usually the biggest expenditure (that is after time, of course) for an EV project - at least I have that avenue covered.
My country requires full certified lab tests for UN R100 compliance, which is a bit BS for one off vehicle conversion. A friend of mine is giving me Volvo 740, I was about to go get a lexus transmission, but after clarifying the legal requirements for a road legal ev swap I kind of calmed down a bit. That's tens of thousands of euros for approval documents. Most likely destructive for some sub assemblies (burining the battery with open flame, WTH)...
After studying the regulations and interviewing local companies who have done homolgation for batteries I got an idea.
Apparently R100 only applies for anything above 60V. The local road authority guy who checks all swap projects was a bit hesitant to disclose this, but after nagging him for an hour he kind of said there are no legal requirements if the battery is below 60V. Just a standard engine swap project and maybe some issues with having to prove hydraulic steering and brake vacuum pump functionality at the local race track.
I have no issues making the battery bus bars temporarily in 59.9V configuration, however under this configuration I would have to be able to reach at least 90-100km/h for those race track brake tests, which scares me a bit.
Anything else similarly fun to do with 50+ kWh of batteries?
I've acquired 500ish 4S drone batteries made by ATL from a drone company I used to work for. Most of them are new, but datecode goes back a few years, so there is some degradation from storage.
They should be rated 6800ish mAh, but are mostly 6000mAh. They are HV, cells are supposed to charge up to 4.35V and there are FPC heaters between the cells. Each pack can safely deliver 15-20A of current. Think of modern DJI drone batteries, but for a different ODM project. My plan is to get rid of the plastic enclosure and current BMS and make modules of 4S10P or 4S20P and then rig them in to something bigger as needed. Do trivial monitoring/balancing with custom pcb per 4S10P pack, which would serve as an internal bus bar as well.
I'm an electrical engineer with (hopefully) enough mechanical engineering skills and I have done ICE engine swaps previously so I am aware on how deep the rabbit hole will go.
I've thought about making a powerwall, but that's no fun. Given that batteries are usually the biggest expenditure (that is after time, of course) for an EV project - at least I have that avenue covered.
My country requires full certified lab tests for UN R100 compliance, which is a bit BS for one off vehicle conversion. A friend of mine is giving me Volvo 740, I was about to go get a lexus transmission, but after clarifying the legal requirements for a road legal ev swap I kind of calmed down a bit. That's tens of thousands of euros for approval documents. Most likely destructive for some sub assemblies (burining the battery with open flame, WTH)...
After studying the regulations and interviewing local companies who have done homolgation for batteries I got an idea.
Apparently R100 only applies for anything above 60V. The local road authority guy who checks all swap projects was a bit hesitant to disclose this, but after nagging him for an hour he kind of said there are no legal requirements if the battery is below 60V. Just a standard engine swap project and maybe some issues with having to prove hydraulic steering and brake vacuum pump functionality at the local race track.
I have no issues making the battery bus bars temporarily in 59.9V configuration, however under this configuration I would have to be able to reach at least 90-100km/h for those race track brake tests, which scares me a bit.
Anything else similarly fun to do with 50+ kWh of batteries?