LumberJocks Woodworking Forum banner

nicad batteries

1K views 10 replies 6 participants last post by  KellyB 
#1 · (Edited by Moderator)
I want to rebuild a 12v battery for my cordless drill.

Has anyone done this and if so, what source do you recommend for the sub-c's with tabs? Lotsa suppliers out there on the www, but it's hard to guess who has the best battery.

Thanks.
 
#2 ·
Don't bother with NiCAD batteries!
if you want to improve battery life and tool usability profile (how long the tool can be used without recharging), switch to NiMH batteries. That is if your charger can handle NiMH batteries, some cant!

A search of the Web you might find a NiMH battery that will fit your tool directly.
I found a 9.6 volt direct replacement for my Makita drill. I bought two of them about six years ago and they have not decayed as a NiCAD would have.

Building your own you will needs tabs for interconnects but I don't know if you can do that and still fit into the same space/package.
 
#3 · (Edited by Moderator)
There are advantages to each, depending on what you are looking for. NiCD batteries have almost twice the charge/discharge cycle life (NiCD is about 500+ cycles, NiMH and Li-Ion are about 300+), lower self discharge rate (NiCd is ~20%/month@77F, NiMH is ~30%/month@77F, Li-Ion is only 3%/month@77F), and NiCD has a wider operating temperature range (NiCD is -22 to 140F, NiMH is -4 to 122F - although they pretty much are useless below 14F, Li-Ion is +14 to 122F). NiCD batteries have more of a memory effect (NiMH have a little and Li-Ion has none), but can be compensated for by periodic conditioning. NiCD is less sensitive to heat, NiMH is fairly sensitive, and Li-Ion is extremely sensitive to heat, particularly for charging. NiMH and Li-Ion batteries have greater storage density so can continue working longer per charge than NiCD, but at the cost of a reduced life span. NiCd batteries must be properly recycled, NiMH are recommend but not required, and Li-Ion can be thrown away without restriction. NiCD batteries are much cheaper than either of the other two. Both NiCD and NiMH are shipped uncharged and must be charged before initial use, and NiMH also need to be further conditioned before initial use (or after storage for 3 months or longer) or their capacity will be greatly reduced.

I've stuck with NiCD batteries, simply because I can get battery packs for my Makita for less than $20 a piece (and they are twice the capacity of the originals). A pack will last me about 5 years or so before needing to be replaced. They may not last as long per charge as the others, but at that price, it's pretty easy to have extras on hand to compensate for that, and they have a longer service life.

YMMV.

Cheers,
Brad
 
#4 · (Edited by Moderator)
Brad,

I found direct NiMH direct replacements for my Makita 9.6 volt drill for nearly the same price from Makita for the NICAD batteries. As I wrote above, I have had these for at least 6 years.

I came back to this post to add the information you supplied.
I also want to reinforce the heat issues with LiPo batteries as my son is an RC car enthusiast, and CNC machinist,. He charges his LiPo batteries outside the house under a ceramic flower pot as one did explode just as he walked away from it. He did wrong it was just a defective battery.

One last thing, hobby shops are a good source for multichemistry chargers at a decent price, about $70, and it charges everything from NiCAD to LiPo and have features that "trickle" chargers do not/cannot supply.
 
#5 · (Edited by Moderator)
My charger will do either… but across the life span of the batteries, NiCD has a much lower cost per charge and almost twice the life (or more, see below). I don't need long run times (and if i do, I just make sure to have an extra pack handy), so NiMH isn't really all that attractive for me. And yes, Li-Ion batteries are extremely sensitive to heat, and the packs have to have special circuitry in them to help keep them safe temperature wise, as do the chargers.

Also… and I'm guilty of it as well… saying a battery pack lasted X years is really kind of meaningless.. it all has to do with how many times you cycle the thing (charge/discharge). A hobby user who infrequently uses the drill will result in a battery that lasts much longer than someone who uses/charges it a lot. Between the two, if charged/discharged at the same frequency, a NiCD pack will last roughly twice as long as a NiMH one (and according to BatteryUniversity.com, three times longer - 1500 cycles for NiCD compared to 300-500 for NiMH according to them).

Cheers,
Brad
 
#6 ·
NiMH is a poor choice for cordless power tools, which is why it hasn't ever caught on in the marketplace. NiMH batteries self-discharge very quickly, and pulling your drill off the shelf only to find that it's completely dead is a real drag.

There are a ton of sub-c NiCD cells available on the internet. They are all the same, buy whatever is cheapest. Are you comfortable soldering the wires to the batteries?
 
#7 ·
thanks for the input. Most votes for what I'm doing points to NiCd's.
I went with NiCd also because that what was there and I don't think the Ryobi charger is smart enough.
What I was really interested in is who makes good quality batteries, and after agonizing for awhile, went with Tenergy. When I asked them about paper-clad vs pvc, they very quickly replied saying that paper was preferred for tools to avoid heat build-up problems at high discharge rates.

I was impressed with their c/s so decided to give them a try.
Battery is rebuilt, is working, so now we'll see about performance/longevity.

I got the batteries with the tabs, so soldering was easy. Just gather them as they need to be oriented, trim any excess tab, and solder.
 
#8 ·
Checkout Voltman batteries

The batteries are wired in series and the bus bars should be spot welded to the battery ends.

It'll cost you about $30 per battery, which is a lot less than buying replacements, but hard to justify, given that you can buy the new Lithium-Ion drill/driver sets so cheap these days.
 
#9 ·
The batteries on my old drill were failing and I looked into replacing them. I found that for less than 15% more I could purchase a new LiPo drill and impact driver kit with two batteries! I decided to purchase the new kit. I will probably end up trying to sell the old drill set on craigslist.
 
#10 ·
Battery is rebuilt, is working, so now we ll see about performance/longevity.
I'm curious as to how much it cost to buy the batteries and rebuild yourself versus buying a new battery pack. Was there a significant price difference or did you just want to try your hand at rebuilding?

Cheers,
Brad
 
#11 · (Edited by Moderator)
Battery is rebuilt, is working, so now we ll see about performance/longevity.

I m curious as to how much it cost to buy the batteries and rebuild yourself versus buying a new battery pack. Was there a significant price difference or did you just want to try your hand at rebuilding?

Cheers,
Brad

- MrUnix
it was $28.00 incl shipping for the cells themselves, and my labor isn't worth a dime to me…or anyone else for that matter (LOL)
A new replacement would have been 34.00, and I would have gotten the same lousy quality batteries which came new with the drill. The new batteries are 2200mAh as opposed to the 1500 or so that were the original. The charger handles the higher ampH ok, so I have hopes for lots better quality at a somewhat lower price.

@dschlic1: Yeah, I know that it's nearly as cheap to throw away the whole shebang and get a new kit, but there is something in me that rankles at that. So I saved a couple of bucks, and now probably the drill itself will crap out!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top