How to revive nicad's

[mattsdragons]

Anyone give me any advice on how too revive some 3am 24v nicad packs? Their fairly old but are still holding some volts, yet I don't know how to treat them, good hard cycle or a low amp slow one?

[terry]

Re: How to revive nicad's

You need to cycle them at around 4amp charge ish it don't matter too much, you propably have a few cells gone so you will have to test to find them 1st and replace them as cycling won't work with damaged cells in the pack.
I got so pissed off doing this so I changed to a123s as the charger automaticly balances.

[mattsdragons]

Re: How to revive nicad's

So take off all the heat shrink and test all the cells, if they read 1.2v then their fine, or could I get away with testing the whole pack and buying enough cells to replace them all, then find the old cells?

I've got all the chargers for Nicads so would like to try and use them, won't be cheap but probably still cheaper then buying A123 chargers and batteries

[beast]

Re: How to revive nicad's

no dont take heat sink off just yet
measure voltage ie 24v
if 24v then charge fully then discharge 3 times or run the bot down street till dead then charge
normally a good charger can cycle theses

if u dont have say 24v then yes have to strip

[mattsdragons]

Re: How to revive nicad's

I've checked my packs and one is 21.6v, the other two are about 16v, so go and take heat sink off and try and find some replacement cells?

They hold 24v after being charged but soon drop back off

[blazerbotics]

Re: How to revive nicad's

16volts is very low, if you have that many cells gone, the rest won't be far behind. You will struggle to get hold of the cells nowadays as well.

[mattsdragons]

Re: How to revive nicad's

Found a source of cells, around £5 a cell, don't know if it's worth a shot and try too get the Nicads back in working order or stick with SLA's till I can afford A123 packs and chargers, though I'm bot sure how much it would be for 3 12v packs

[jonny]

Re: How to revive nicad's

http://www.ebay.co.uk/itm/10pcs-New-Ori ... 211wt_1114

you'll want atleast 3 packs of 8 cells so you're looking around £130 for batteries plus another £100 for a cellpro 10s charger.

[mattsdragons]

Re: How to revive nicad's

Not as bad as I though it would be but would 2300mah be enough?

[jonny]

Re: How to revive nicad's

3x 2.3ah = 6.9ah. That should be enough for bulldog as you're only running Bosch 750s on 24 ish volts.

[terry]

Re: How to revive nicad's

I run 4 packs of 2.3ah, normally use around 5amp at the most in fights so 3 packs would be enough.

[mattsdragons]

Re: How to revive nicad's

So 24 cells would make me up 6 12v packs as each cell is 3.3v? The old set up was 3 12v nicad packs all into 3 different plugs, so I could make up enough to have a full set of spares put of 24 cells?

Or better to make a 2 24v packs? Can run 24v worth of hawkers on a single lead out of the 3 but still trying to get my head around the wiring and how many packs I could/would have too use and at what voltages

[jonny]

Re: How to revive nicad's

3 packs of 8 cells!! The three packs Wired in parallel to give 26.4v 6.9ah

[mattsdragons]

Re: How to revive nicad's

May have to re-do the wiring slightly then to adapt for the new packs

anyone know of any good chargers that are not £100 each, bit steep for £420 in total for a conversion so want too bring that cost down a bit really

How viable would it be to use 8.4v nimh packs of the same 3000mah? would need 3 packs of 3 so 9 packs in total, but comes out at under £200?

http://www.wheelspinmodels.co.uk/i/70479/

Just exploring different ideas here, dont want to run SLA's forever

[jonny]

Re: How to revive nicad's

How Is £120 + £100 £420?

You could probably use turning accucel 8s as you're only running 8s packs.