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Recell battery packs?


#1

Anyone know where I can get some battery packs recelled?
I have a couple of Kenwood G-71E handhelds and 650mAH and 1400mAH PB38 battery packs for both. The two 1400mAH have both died and no doubt the smaller packs won’t be far behind. Date of manufacture is Oct 2004 so we have had 6 years out of them.

Steve GW7AAV


#2

In reply to GW7AAV:

If you’re not ham fisted they are easy to re-cell yourself. Wrap the pack in cloth and them hit along the seem with a small hammer. This is normally enough to crack the glue/weld and the pack can then be opened and the cells removed.

It’s likely if the cells are series charged than most will be OK and just one or two will need “education” so they “get with the program” ! This is best achieved by charging up a Schwarzenegger sized capacitor (say 70,000uF) to about 12V and then connecting the capacitor across each cell. There’s enough energy in the capacitor to melt any internal resistive paths in the cells. That can occur with poor charging regimes. But there’s not enough energy to do any damage. Don’t use a car battery or PSU, you need something that has a finite amount of zap as you can sometimes spot weld the wires to the cell. You don’t want to do that with a car battery (capable of >5000A in a short circuit).

Reassemble and cycle the pack a few times and you should find 85-90% of normal service has been resumed. However, if the pack doesn’t respond you can buy tagged cells and assemble them yourself. Or if you are a complete CBER (Cheque Book amatEuR) you can send the packs to Strikalite (http://www.strikalite.co.uk/) who will re-cell them for you. Or you can look on eBay and see what the Chinese cloners are selling on the world’s biggest tat bazaar just in case they have a suitable pack at a reasonable price.

I’d give them a zapping first as you have little to loose.

Andy
MM0FMF


#3

In reply to MM0FMF:

Hi Andy I have never managed to get one of these packs open without completely destroying it. I do however have access too thousands of duff packs I could practice on. I have tried all the usual tricks of discharge and charge. A dirty charger usually does the trick, sometimes just charging from the cigar socket in the car is enough. One of these packs simply does not take a charge and the other charges for the normal time, shows full voltage and then dies as soon as you hit the TX button. All the packs are NiCd so getting them recelled should improve things as it will be with Ni-MH these days, because you can no longer import NiCd cells in to the EU. I have never seen Kenwood P38/39 clones from any Chinese outfit but the Americans do them. The problem there is the cost of importing from the US exceeds the cost of the cells. Strangely their larger packs are 800mAH or 1100mAH where as mine were 1400mAH.

Steve


#4

In reply to GW7AAV:

There is a knack and some are easier than others. My Icom PB157 came apart in moments and quick ker-zap with “battery educator” and it was back to life. Which sadly can’t be said for my 23cms handy which has now expired. It had been misbehaving for sometime though. I guess a 1992 vintage obscure handy just didn’t like getting cold on the summits. :frowning:

Strikalite will supply cell packs for you to install in your own case if you want. I’ve used them a few times and speak as a satisfied customer. Other battery vendors are available!

Andy
MM0FMF


#5

In reply to MM0FMF:

I have been reading about freezing the batteries and then giving them a whack or tapping them with the blunt end of a screwdriver for a minute to break up the crystals that form. I was thinking maybe a bit more thermal shock would be more effective. Put them on the radiator until they get hot and then drop them in liquid nitrogen ;0) Do not try that at home!

Based on that idea keeping your handheld (or the batteries anyway) in the car might slow the formation of crystals due to the extremes of temperature, the vibration of the vehicle and rough DC charging.

Steve


#6

In reply to GW7AAV:
I have had trouble in the past breaking into these packs without doing damage, I now use an electric engraver, I simply engrave around the seam and its pops open with minimal mess and damage.

                                Sean M0GIA