Charging NiCd battery packs

#1

Hi all,

I have a NiCd battery pack,

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And a bench power supply.

Any wise advice on making one fill the other with electrons? Or should I suck it up and buy the correct charger?

P

#2

tldr:
i feel like but cannot imperically back it up that setting bench supply to 14.4v @ 150ma would be pretty safe and take 10 hours to charge give or take. adding more current would reduce the time required obviously. faster charging could mean more heat though, so if you are impatient like I am then you would probably feed it a full charge in an hour but would need to keep checking its not too hot.

ive not recharged nicads directly myself but as long as you set a constant current with your bench supply, you should be fine.

i had a quick google and the rate of charging seems to be fairly forgiving, ranging from a tenth of the capacity through to sending the full capacity into it as a fast charge. so i guess 1.5amps down to 150millamps would be the comfortable range.

i saw differring suggestions for how much voltage to apply to each cell, suggesting 1.2 through to 1.55v.

determining when a battery is in fact charged is a bit tricky, seems the voltage at the battery terminals will rise continuously during a charge cycle but then once 100% subtly drop off some voltage which is what a charger would look for.

2 Likes
#3

Constant current source that shuts down at the maximum voltage of the battery

1 Like
#4

thanks all, never got past 2.5v, so I assume pack is borked.

#5

thanks for the update, shame though