SubnetMask
1 mW
- Joined
- Apr 17, 2020
- Messages
- 19
First, let me start by saying I know that NiMH chargers are not meant for use with Li-Ion and would likely destroy the cells at minimum (and best case) - my thought is to not charge the batteries with the original charge mechanism. Let's assume for a second that I want to make a pack where the cells are removable so they can be charged in a LitoKala or similar charger.
That being said, I have a WireScope 350 set with dead battery packs that use 3800mAh 4/3A NiMH cells in a 6S configuration for a 7.2v nominal pack. These packs are 'obsolete', and if you can find them, they're $200+ from what I've found. From what I gather, it seems like a fresh, fully charged AA NiMH is 1.4V, so since the 4/3A and AAs are both '1.2v' batteries, assuming this info is correct, then the fully charged voltage of a NiMH 6S pack is 8.4V - a fully charged Li-Ion 2S pack would also be 8.4V. From a purely 'power the device' perspective, and assuming that charging will never be done as it was, through the device, does it seem like replacing the 6S 4/3A NiMH batteries with a Li-Ion 18650 2S or 2S2P pack would be safe for the device? For discharge, I could get a small BMS to prevent the batteries from being over discharged, but if the voltages seem safely in line for the device, I'd look to find a way for the cells to be removable so I can charge them externally with a proper Li-Ion charger.
That being said, I have a WireScope 350 set with dead battery packs that use 3800mAh 4/3A NiMH cells in a 6S configuration for a 7.2v nominal pack. These packs are 'obsolete', and if you can find them, they're $200+ from what I've found. From what I gather, it seems like a fresh, fully charged AA NiMH is 1.4V, so since the 4/3A and AAs are both '1.2v' batteries, assuming this info is correct, then the fully charged voltage of a NiMH 6S pack is 8.4V - a fully charged Li-Ion 2S pack would also be 8.4V. From a purely 'power the device' perspective, and assuming that charging will never be done as it was, through the device, does it seem like replacing the 6S 4/3A NiMH batteries with a Li-Ion 18650 2S or 2S2P pack would be safe for the device? For discharge, I could get a small BMS to prevent the batteries from being over discharged, but if the voltages seem safely in line for the device, I'd look to find a way for the cells to be removable so I can charge them externally with a proper Li-Ion charger.