Replacing NiCd cells in Rolleiflex SLX pack with NiMH

[Tony-S]

I need to rebuild my SLX battery pack and Google led me to this page:

http://www.graham-mitchell.com/blog/?p=72&cpage=1

This discusses the replacement of the NiCd batteries in the SLX pack with NiMH cells, but states that the charger won't work. I'm pretty sure it'll charge the NiMH batteries just fine, but the risk is overcharge. So if the OEM pack with the NiCd batteries completes the quick charge in 1 hour, and the full charge in 3 hours, wouldn't it be safe to charge the NiMH batteries for a couple of hours and then just use them? I suspect the OEM NiCd cells are probably in the 700 mAh range, but will know for sure when I disassemble the pack. I'm looking at replacing them with the following 2/3A 1.2V 1400 mAh cells:

http://www.batteriesinaflash.com/as...hargeable-battery-1400mah-nimh-1-2v-ft-w-tabs

I'll have our local Batteries Plus do the spot-welding of the 8 cells.

 

[ic-racer]

Why not just use the Sanyo 'high capacity' Nicads and the Rollei charger?
Dead Link Removed

 

[Tony-S]

I'd like the 1400 mAh over the 600 mAh of the NiCd batteries.

 

[Mike Wilde]

I'm in a different situation over a pack rebuild. I just put a 12V 2.3Ah $20 Valve regulated lead acid battery into an old Norman 200B, whose 30 year old nicads were kaput. The charger (a blue one - early model) puts out 180mAconstant current on slow charge, and about 1.5A on fast charge. I use it on slow to charge the VRLA, until the voltage rises to between 13.8 and 14V. It does have to be watched, becuse if you open circuit the thing the voltage will jump to over 18V.

SLA should be charged on constant voltage, but smallest the electrical wholesaler had put out 900mA, and the battery says on its side not to charge faster than 690mA to start. The charger was $45. So if I fry the battery after 6 months, the cheaper fix here is to just alternate between 2 batteries.

I did have to adjust the oscillator potentiometer