Handheld VHF - Rebuilding the battery pack

superheat6k

superheat6k

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I have an old but perfectly functional Swiftech hand held VHF. However, the two battery packs I have are both past it and only hold charge for a short period.

I can pop one of these open to reveal a pack consisting of 8 cells about the same size as AAA. Can I simply solder together 8 new Ni-MH AAA cells, or do I need to be a bit more careful about getting the cell voltages matched. The output from the pack is 9v, but these is a small regulator circuit within the pack.

I could simply wire 3 PP3 rechargeable in parallel to gain the same capacity, but should I retain use of the regulator circuit board.
 
superheat6k said:
Can I simply solder together 8 new Ni-MH AAA cells, or do I need to be a bit more careful about getting the cell voltages matched. The output from the pack is 9v, but these is a small regulator circuit within the pack.
Click to expand...

It's certainly do-able, but a bit fiddly. Easier if you buy tagged cells. Be sure to photograph or draw diagrams of how the cells are interconnected, and how the circuit is wired. The circuit is probably to govern charging.
 
Basically you are saying you don't know the chemistry of the existing cells.
Given the fact that there is a circuit build into the battery pack could point towards a Lithium battery pack.
That uses a different regime compared to the alternative NiMH. I'd be careful in swapping cells until you know what chemistry you are dealing with. A poor charging regime can lead to nasty effects on the long run.
 
aluijten said:
Basically you are saying you don't know the chemistry of the existing cells.
Given the fact that there is a circuit build into the battery pack could point towards a Lithium battery pack.
Click to expand...

It's an old Swiftech radio, it certainly won't have a lithium-ion battery! Probably NiCd originally, but NiMH would work OK in it.
 
A check of good ole ebay indicates AAA with tags are rare the only supplier being in UK. You want the max Milliamp hour capacity. You may get away with non tagged NiMH AAA batteries but you need a big soldering iron to get heat quickly onto the battery body. soldering will be the most difficult part even with tagged batteries. I think I would go for cheap Chinese AAA and solder on however that may prove to be a bad choice. Just make sure you get the right dimensions before buying.
good luck olewill
 
There was room in the back of my old Sealab HH for 2 x 4 AAA battery boxes, allowing standard AAA rechargeables to be used.

sealab.jpg
 
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