Replace NICD cells with NIMH

[oaa]

I have some old Astro Saber R NiCd batteries and I want to rebuild them with NiMh cells. I will use a WPLN4111 Impres charger. Will this be possible to do? Is the charging pattern regulated by the components inside the battery or in the charger?

 

[GTR8000]

The WPLN4111 is a tri-chem charger, so it's capable of charging NiCad or NiMH or Li-Ion type batteries. I can't speak to the specifics of replacing the cells in a Saber R battery pack, but I suspect you'll be okay.

 

[RFI-EMI-GUY]

You would be far better off replacing the cells with two protected lithium ion cylindrical cells in series and using a wall wart style 8.4 V Li-Ion charger. I have modified a few batteries like this and performance is outstanding. I got some 8.4V two cell packs from Tenergy that fit and used a coaxial DC connector to mate with the wall charger.

The hardest part will be getting the OEM battery apart and removing the cells. If you can, try to save the Kapton wiring in the battery from damage. Otherwise, I have had to solder directly to the +/- terminals deep in the case which is tricky. Keep the plastic from melting by placing that end in a pan of water. Use two layers of aluminum foil to keep the soldering iron body from melting the case.

 

[oaa]

You would be far better off replacing the cells with two protected lithium ion cylindrical cells in series and using a wall wart style 8.4 V Li-Ion charger. I have modified a few batteries like this and performance is outstanding. I got some 8.4V two cell packs from Tenergy that fit and used a coaxial DC connector to mate with the wall charger.

The hardest part will be getting the OEM battery apart and removing the cells. If you can, try to save the Kapton wiring in the battery from damage. Otherwise, I have had to solder directly to the +/- terminals deep in the case which is tricky. Keep the plastic from melting by placing that end in a pan of water. Use two layers of aluminum foil to keep the soldering iron body from melting the case.

Ok. Thanks for answer! I have rebuilt a lot of batteries so this is not the biggest problem. But this time i wanted to change the chemistry in order to get some more capacity. So i wondered if the thermistor and resistor in the batterycase would be a problem due to wrong temperature or overcharging the NiMh cells??...- - or will this be regulated by the Impres charger?.. I have ordered Tenergy 3200 MAh cells..

 

[RFI-EMI-GUY]

Ok. Thanks for answer! I have rebuilt a lot of batteries so this is not the biggest problem. But this time i wanted to change the chemistry in order to get some more capacity. So i wondered if the thermistor and resistor in the batterycase would be a problem due to wrong temperature or overcharging the NiMh cells??...- - or will this be regulated by the Impres charger?.. I have ordered Tenergy 3200 MAh cells..

If you are going the NIMH route, you can get a hold of the manual for the old style Saber charger and find the charging resistor values listed. As far as the thermistor, I cannot say if the manual mentions that. Better to compare the value in another NIMH battery because it probably affects the delta T point where the rapid charge switches off.

I got so sick and tired of NICAD and NIMH batteries failing that I went to Li-ion batteries for my Systems Sabers. I have some from eBay that are Chinese 5500 man and use the 8.4 wall wart charger from same seller. I also have my homemade batteries using same charger and Tenergy cells as well as Panasonic. plus some Honeywell batteries that were NOS , dead due to protection circuit cutoff (Low Voltage) and I recharged them perfectly. These batteries are always ready with a charge, very little self discharge.

 

[RFI-EMI-GUY]

As a followup. I don't think the impres chargers worked any different than standard Saber Rapid charger. I don't think there was an impres option for NICAD OR NIMH Saber batteries.

 

[RFI-EMI-GUY]

Here is an 8.4V 2200 mAH protected Li-Ion battery pack that I have installed in the larger 1800 mAH OEM Saber battery cases.

This seller has complete 5500 mAH Li-Ion batteries for the non ruggedized Saber complete with the charger. He also sells the charger separately. You might be able to transplant the innerds of one of these to an 'R battery.

Li-ion Battery For Motorola Astro Saber Radio +Charger Syste | eBay

Not Contain Hydrargyrum, Lead and Cadmium. Astro Saber I, Astro Saber II, Astro Saber III, MX100, MX1000, MX2000, MX3000, MX3010, Saber I, Saber I R, Saber II, Saber II R, Saber III, Systems Saber I, Systems Saber II, and Systems Saber III, etc.

www.ebay.com

I should add, you knock off about 6 oz weight compared to NICAD using the 5500 mAH batteries from this seller. My homemade batteries with 2200 mAH cylindrical cells perhaps an oz or two lighter.