craftsman c3 batteries

[leigh6443]

To all those with the Sears C-3 Ni-Cad batteries: I have had the C-3s for years along with a few tools that use them. In my area, we have a company named Batteries and Bulbs and they rebuild these batteries but, only Ni-Cads. If you ask, they will rebuild the C-3 batteries to OE standard however, they will rebuild your batteries with a better Ni-Cad for a few bucks more. They're not cheap but they will get you going.

I had an experience with one Li-on battery; it worked until the electrons ran out. I then found out it would not recharge in any of my rechargers (3, and one is a Li-on charger). B and B would not work on it because of the danger of Li-on batteries. My advice: do not purchase C-3 Li-on batteries. a waste of money.

Here's a PS: do not open a Li-on battery pack; if you do, you could be endangering yourself, your family and/or your home. Li-on's are nasty if shorted or punctured.

 

[JazzBlueRT]

I have a dozen or so of C3 Li-on batteries most are over 10 years old now. When they wont charge, I drain them in the LED flashlight and they they recharge.

Not all C3 chargers are the same either. As I understand it there is a slow and a fast charge and the charger has to be capable of slow charging until the battery reaches a certain threshold.

The charger which works best for me is the one with the radio or radio with the charger.

 

[Bubba Fett]

Tangently related: I take apart battery packs from old laptops and pull out the 18650 Li-Ion cells. I have chargers for individual cells, so I can recharge them and use them in flashlights.

 

[Bacon!]

^ Yes it's definitely easier to do with the laptop packs due to the outer casing, "usually", also being the primary holder for the cells.

Li-Ion tool batteries larger than 12V are trickier since they tend to have the plastic spacer/holder/whatever (I'm sure there's a proper name for it but I can't recall at the moment) then spot welded together so you're left breaking chunks off that holder or gingerly trying to cut the welded tabs apart, usually with very little clearance to do so. I have done that to harvest cells, primarily for flashlight use.

There is a danger but I do it on a tray and could just carry the whole thing outside, and usually do it in the garage where they could just burn on the concrete floor if worst came to worst, and garage door open to ventilate the area.

Places that rebuild packs, ask questions... do they use major brand cells like Sanyo, Sony, LG, etc (or whoever is still making Ni-Cd, maybe none of the majors are any longer) or are they just sourcing Chinese cells that make claims of same specs but usually fall short, in either self-discharge rate or cycle lifespan if not both?

Ask what this "better" NiCd is, merely having a higher mAh capacity rating doesn't necessarily make it better for tools as they tend to use a construction method that isn't capable of as much current which is why it was so common to see NiCd packs with major brand cells having as little as 1.2Ah to 2.4Ah and not more than that. The other question is at what cost? Good cells are not cheap, might be as well off buying the Li-Ion packs and just accepting that they wouldn't be rebuilt, if they're major brand not generic, because high quality major brand Li-Ion cells are current production so at least it's more viable to make a high quality battery pack using them... but with generic brands all bets are off.

The catch is that since a typical NiCd tool has no low voltage shutoff circuit in it, the battery pack itself has to have this in the BMS board or else cells can be drained too low, but a generic may not be so conservative with that voltage cutoff point to make the pack appear higher capacity. Similarly if you deep discharge one you can't then leave it sitting around for months to further discharge or else may fall too low for the charger to accept. There are some tricks to get a charger to accept them but they aren't entirely safe as it was intentional to not allow recharging Li-Ion cells that were drained too low.