Ni-cad's

[davelectronic]

I was just looking for advise of battery care for longevity. As I'm using cordless tools but only occasionally, I was wanting best battery maintenance to extend useful life. I have googled this quit a bit to see what's best practice, I know I've really got the not best battery chemistry for occasional use but have invested now. The advise I was after is periodic possible charging, avoiding memory affect, and at what state of self discharge to charge back up if necessary. Really all this is as said it to maximize longevity for moderate to low use of these units. A typical battery is 24 volts at 1.2Ah and I have two of these I would like to keep in good serviceable condition for as long as possible, battery's are currently charged per recommended by manufacturer and idle at present. Thanks for reading, any advise appreciated.

 

[shrtrnd]

I don't know what advances may have been made in NiCad technology lately. This is my experience with the ones I use, mostly in low-power communications.
It's bad to use them 'occasionally'. The darned things work best (have longer usage-time/capacity) when they see frequent usage. I have a drill that uses them, but because of my experience, I have a flashlight attachemnt for the same battery, so that I use the battery for my flashlight, knowing it'll get infrequent use on the drill. You already know about battery 'memory', if that's still an issue with modern NiCad battery chemistry. Run them down before recharging them. I like NiMH batteries better, though some people swear by the Lithium ones these days. Having the NiCads already, I'd look for a flashlight or something else to use the battery with, so that it/they see more frequent cycle-time, rather than sitting idle in the infrequently used drill.

 

[Merlin3189]

In my experience overcharging is a problem. The chargers that come with cheap (I have no experience of expensive ones!) electric drills, screwdrivers, torches, toys, etc. have no regulation, control or timer. If they are capable of charging in less than about 14 hrs, then they will be overcharging once the battery is full. So be very careful not to overcharge by going over the required time. Of course you can't always know how discharged they are, so I charge fairly cautiously and check frequently for warming (a sign they are into overcharge.) I give a full timed charge when I know the battery is more or less empty. (I try to avoid dead flat in any battery pack, because by then the weakest cells may be reverse charged. I stop using as soon as there is a significant drop in power.)
I have not noticed problems with occasional use, though NiCads do loose charge relatively quickly. They are supposed to be happy if they are left in any state of charge, including flat.

 

[davelectronic]

Thanks for the info, yes I knew less use tends to be worse overall for longevity, so really I should periodically run them down but not completely flat to avoid this reverse charge scenario. Don't have a torch attachment with any set, so guess a pair of 12 volt halogen lamps will have to do, but must avoid complete flat discharge, as for over charging it states 3 - 5 hours charge time, and yes they don't disconnect once charged, its a Manual turn off, I am going along the lines of 3 hour charge if not complete flat, or 5 hour charge if all but flat, I will remember to avoid frequently partial charges, think this all sounds ok, thanks again.

 

[shrtrnd]

Just some more of my experience. If you do leave the batteries unattended for any extended length of time, the capacity will appear lessened, but don't be discouraged.
If I cycle mine a few times (charge/discharge) I get my usage-time back (my battery-run capacity). Don't think the batteries were damaged, they'll come back ok.

 

[davelectronic]

Thanks for the tips, in likeliness my two battery's won't see a lot of action, info taken on thanks for your help.