Should I rebuild or just replace worn out cordless tool batteries?

Question

I have a couple of older Porter Cable 19.2v Ni-Cd batteries which have worn out. In shopping around for replacements, I've noticed there are a number of businesses which offer to rebuild your existing batteries with new cells.

One of the claims that some rebuild shops make is that they use high capacity cells (2400mAh) which will give longer run times compared with OEM batteries. Also, since my tools are older, replacements are a bit harder to find. The cost difference doesn't seem that significant (rebuilding seems a bit cheaper).

Can anyone give me a rundown of things to consider when deciding to rebuild the batteries as opposed to replacing them? I'd also like to avoid an experience I had about 5 years ago where I purchased a set of 2 "new" Dewalt 18V batteries from an online retailer only to find they did not perform nearly as well as the original batteries that came with the tools.

Answer 1

Rebuilding NiCd battery cell packs can be a good alternative to buying new packs. There are really only a few manufactures of these type of cells, but the quality can differ as the prices may indicate. The majority of the price of a new pack is the pack package itself, which is specific to each tool, even though the cells inside are pretty similar. The amp hour rating and number of recharges it will take are the most important thing. I have noticed that the Porter Cable battery packs are a lot less expensive than most of the other brands. To be honest, I haven't researched the brand of cells they use as an OEM, but you can get info online about cell manufacturers and ratings on the quality levels. I would look closely at the warranty the rebuilder is offering, which cells they are using and avoid a bargain basement price with a poor warranty or hidden costs such as a "recycling fee". A supper low price on a rebuild or a complete replacement may indicate a clearance of old stock. NiCd's hate to sit around for long periods uncharged, which can really affect performance and charging ability. Check the date codes and don't accept any that may be much over 6 to 9 months old.

Answer 2

I thought about doing it myself until a) I took apart a battery pack and saw how complicated the array 20 little batteries was and b) I saw the price of 20 little batteries. Since the price of the replacement batteries would cost as much as a new battery pack I opted for a new pack. I thought about going with a different chemistry (like NiMH instead of NiCd) but the thought of the pack exploding because I used the wrong charger scared me.

Answer 3

I have seen mixed results with battery re-builds. One guy I knew had one of his re-built and was very happy with the results, and went back to have two more done. Another friend had one re-built and the battery was fine for short charges but wouldn't every charge fully and didn't have the 'power' of the old batteries. So I think this is one of those times it is going to vary wildly depending on a whole host of factors.

It may be worth contacting porter cable, to see if they have new batteries that are adaptable to the old tools, or if you can order replacements through them (they may not be advertising old battery styles to encourage people to buy new ones)

Answer 4

I just rebuilt 3 battery packs with 2800mAh cells. Cost me $32 and only tools I used were cordless drill with star bit to disassemble, razor to cut back heat shrinked battery leads and a soldering iron. You could also rebuild using Lithium Polymer packs like those used in RC toys. Put two 11.1V packs in series and buy a new charger for $8