Portable Drill Batteries

Every common homeowner who owns a portable drill has probably dealt with a dead battery. The primary reason they die is lack of use. There are plenty of discussions on “memory effect” to be found online if you are interested in the science behind the reason. Personally, I found many of the explanations to be contradictory and some outright dismissive of the argument, but I digress. The fact remains that I had an unusable drill and my wife needed new shades to be installed.

There are two options to correct a dead battery problem:

1. Buy a new replacement
2. Rebuild the dead battery

Buying a new replacement battery can be rather expensive. That’s why it’s advisable to either purchase a corded drill or one that offers affordable battery replacements if you won’t be using it frequently. Perhaps unwisely, I didn’t do either. I own a DeWALT DC727 which I found for a good price on eBay. A new battery pack runs at $52.55 on Amazon.com.

The other option is to have a dead battery rebuilt with new cells. BatteriesPlus here in Austin would do the job for $50. Obviously in this case there is hardly any savings with the rebuild. However, being the frugal person that I am, I began to wonder if it was possible to do the rebuild myself.

I first disassembled the battery pack and learned that it would require 10 rechargeable NiCd 4/5 Sub C cells (I found the size by measuring the height and diameter of one of the cells). I was about to purchase a set from BatterySpace.com before I managed to find a set of 20 on eBay for $35.50; now I would be able to rebuild both of my dead batteries.

Now came the hard lesson – soldering the batteries together is a pain. First of all, the batteries came with the necessary tabs to connect them, however half of them had to be popped off because they needed to be reoriented in the proper configuration. Second, the batteries came precharged so it wasn’t difficult to shock myself while lining them up. Third, the solder would not hold the tabs. Roughing the terminals up a bit with sandpaper aided some, but not sufficiently. By the time I had them decently attached, the slightest excess of solder buildup prevented the outer case lid from shutting tight. All in all, I spent over 3 hours of fruitless labor on this task before throwing in the towel.

At this point my only saving grace came after I set aside my pride. I humbled myself, picked up the second set of batteries and the case, and headed over to BatteriesPlus. They installed the cells for $16.

So, excluding the time lost on trying to do it myself, a single battery rebuild came out to be $33.75. That’s a savings of $18.80.