Dewalt 18 Volt Battery Repair

[dmill89]

Re: Dewalt 18 Volt Battery Repair

that said, the world is clearly using the u.s. as a dumping ground for old stock while they can still sell it.

Yep, you have to be careful buying cheap off-brand brake pads/shoes (not that buying cheap brakes is ever a good idea) in the US too, since asbestos is still legal in the US as well, and many of the cheap Chinese/Indian pads/shoes still have it (the major brands fazed it out years ago for fear of lawsuits, despite the lack of a mandate).

[R_J]

Re: Dewalt 18 Volt Battery Repair

They seem to care about the Cadmium in batteries more than the do about all that jewelry that comes from China thats loaded with Cadmium.

[stj]

Re: Dewalt 18 Volt Battery Repair

you think that's bad, the indian's found out a while back not to buy recycled gold for jewelry or dental work.

i'm not blaming the recyclers, no seperation system is 100%,
but buyers need to understand that recycled gold contains trace levels of lead, tin, copper, bizmuth, all kinds of stuff.
use it to plate connectors or make coins / bars, but not jewelry or dental stuff!

[momaka]

Re: Dewalt 18 Volt Battery Repair

Anyways, I'm looking for repair options. I can solder and have the tools. Is this repairable, or should I trash it and just buy another battery?

Looks like some of the batteries in the pack have quite a bit of corrosion on them. Probably vented already and developed high ESR (hence why you still see full voltage on the bad battery pack but can't pull any reasonable current from it).

Thus, I would say buy a new *genuine* brand battery pack.
*OR*
Get some new name-brand (Energizer, Sanyo, etc.) quality Ni-MH cells and replace all of the Ni-Cd cells in the bad battery pack.

Either way, SAVE the non-corroded Ni-Cd batteries from the bad pack. Ni-Cd batteries are tough little bastards and can provide many many years of service life if charged and used properly. They can also be stored for a very long time without ill effect. Thus, when your other pack gets a few bad cells, you can use the "good" cells from this pack and replace the bad ones in that pack.

As for the memory effect: it's easy to deal with it. Simply discharge each cell one by one down to 0 (zero) volts over the course of a few days (put a small bulb across it). This will break up the dendrites that often cause the memory effect.

As long as Ni-Cd batteries are not overcharged too much (so that they vent and lose electrolyte), they will provide a very long useful service life - typically 10 years or even more.

Last month, I charged some 9.6V RC car batteries that I put in storage 10 years ago. Guess what, they took a charge and run like new. Can easily pull 2-3 Amps from one of them 600 mA AA cells.

[dmill89]

Re: Dewalt 18 Volt Battery Repair

Thus, I would say buy a new *genuine* brand battery pack.
*OR*
Get some new name-brand (Energizer, Sanyo, etc.) quality Ni-MH cells and replace all of the Ni-Cd cells in the bad battery pack.

Normally I'd tend to agree, but I've actually had pretty good luck (of course YMMV) with Chinese lead-acid, Ni-Cd, and Ni-MH batteries (granted the mAh ratings are often a bit "inflated"), I wouldn't touch Chinese Li-Ion/Li-Po cells with a 10-ft pole, but for less sensitive "simple" (Ni-Cd, Ni-MH, lead-acid) batteries they are often ok. Maybe not as good as their Japanese equivalents, but at around 1/5-1/8 the price (Panasonic/Sanyo Sub-C Ni-Cd cells go for nearly $10 ea., while the Chinese cells are selling for $1-$2 ea.), they often aren't a bad option if you are on a budget and don't necessarily need "maximum capacity". If you don't want to buy the cells and rebuild it, it looks like entire Chinese De-Walt compatible 18V packs look to be selling for around $20 on eBay vs. around $50 for a "genuine" De-Walt pack (that may or may not have Chinese cells in it anyhow).

[momaka]

Re: Dewalt 18 Volt Battery Repair

Normally I'd tend to agree, but I've actually had pretty good luck (of course YMMV) with Chinese lead-acid, Ni-Cd, and Ni-MH batteries (granted the mAh ratings are often a bit "inflated")

With Lead-acid and Ni-Cd, I can understand - simpler and proven chemistry, so less to get wrong. I still have cheap Ni-Cd batteries back from the days when I used to play with RC cars (a little more than a decade ago now) that still hold a charge just fine. Some of the packs got ruined by dumb chargers, but even those packs still have good cells in them that hold a charge okay.

As for Ni-MH, I think the quality of the cells varies way too much between different Chinese manufacturers, and it's hard to tell what you are going to get. For example, I've bought replacement Ni-MH battery packs (on eBay) for our cordless phones before, and they didn't last even a year (after 6 months, they started seriously degrading). The original Ni-MH packs were also Chinese, but apparently of higher quality and actually lasted for 3 years. I've seen this with other devices as well. Also, I'd like to note that I did NOT get the absolute cheapest Ni-MH replacement packs for our phone. I scrolled down through the various listings and bought what seemed like a more reasonable pack with a supposedly honest, non-inflated label.

Thus, when it comes to Ni-MH, I just don't trust the cheap batteries sold online from overseas anymore. The ones sold in big electronics retailers (like Radio Shack, Micro Center, and Best Buy) seem to be better in quality. Those are pricier, of course. So in the end, I guess you do get what you pay for. But personally, I am a fan of the low self-discharge Ni-MH chemistry now (like Energizer Enerloops). Sure the capacity may be lower, but at least the batteries last. The only reason I don't recommend the cheap Ni-MH cells online is because I have no way of telling how to pick a "good one". But if you do, give us a holler . I also have some drill battery packs I may need to rebuild (currently using the drill with a Xbox 360 12V power supply ).

I wouldn't touch Chinese Li-Ion/Li-Po cells with a 10-ft pole

Me neither.
Not quite interested in burning down our house just yet.