BaconButtie
New member
- Joined
- Dec 10, 2017
- Messages
- 22
Well, finallygot round to it after much searching and reading, time to build a portable 12v power case.
Sourced my cells from eBay, mainly from old laptop battery packs but the cells I chose to use are from old Ebike packs as I managed to source 3 used ones of the same make & model which used identical cells, all PanasonicCGR18650CG cells @ 2200mAh (the silver ones in the photo) I had to re-wrap them as they had been super glued together so the original wrap got destroyed during disassembly.
I have gone for a 4s 20p set up in 4 packs wired in parallel to give a total of 80 cells and around 16v 175000mAh output if my understanding of how parallel / series connections work is right :-/
This is to be housed in a custom made flight case (not yet built this) and run through a DC to DC buck converter to give a stable 12v output then supplying 4 USB charging ports which have built-in12v to 5v converters, 1 x 12v car auxiliarypower socket (lighter socket) to power a removable12v LED light.
Charging & balance ports will be accessiblefrom the outside of the case mounted on a custom IO plate so there is no need to open the case to charge the battery.
So far I think I am OK with the theory of how all this works. The only bit I am stuck on is fusing. Is it 100% essential to have cell level fuses or can I just use 1 fuse on the main live feed or will this only protect the output terminals and not the cells?
If cell level fusing is needed is tinned copper wire sufficient for this and if so what AWG would you recommend, bearing in mind the total Amp draw if all outputs are being used would not exceed 3amps max. (2 x mobile phones, 1 x Bluetoothspeaker, 1 x LED light)
Any suggestions, tips or criticisms are welcome as I am a complete noob at this although I do have a basic understanding of electronics but mainly in domestic power supply.
Sourced my cells from eBay, mainly from old laptop battery packs but the cells I chose to use are from old Ebike packs as I managed to source 3 used ones of the same make & model which used identical cells, all PanasonicCGR18650CG cells @ 2200mAh (the silver ones in the photo) I had to re-wrap them as they had been super glued together so the original wrap got destroyed during disassembly.
I have gone for a 4s 20p set up in 4 packs wired in parallel to give a total of 80 cells and around 16v 175000mAh output if my understanding of how parallel / series connections work is right :-/
This is to be housed in a custom made flight case (not yet built this) and run through a DC to DC buck converter to give a stable 12v output then supplying 4 USB charging ports which have built-in12v to 5v converters, 1 x 12v car auxiliarypower socket (lighter socket) to power a removable12v LED light.
Charging & balance ports will be accessiblefrom the outside of the case mounted on a custom IO plate so there is no need to open the case to charge the battery.
So far I think I am OK with the theory of how all this works. The only bit I am stuck on is fusing. Is it 100% essential to have cell level fuses or can I just use 1 fuse on the main live feed or will this only protect the output terminals and not the cells?
If cell level fusing is needed is tinned copper wire sufficient for this and if so what AWG would you recommend, bearing in mind the total Amp draw if all outputs are being used would not exceed 3amps max. (2 x mobile phones, 1 x Bluetoothspeaker, 1 x LED light)
Any suggestions, tips or criticisms are welcome as I am a complete noob at this although I do have a basic understanding of electronics but mainly in domestic power supply.