While talking to a fellow the other day about power tools we got the the topic of lame batteries. I was complaining that my old 12V Milwaukee drill had two batteries that would no longer hold a charge. And that replacement batteries were going to cost me more than a new drill. He suggested I voltage surge the batteries. I had never heard of the term but he gave me detailed instructions on how to do it. Basically the NiCD cells have crystals that develop in them over the years that need to be broken down in order for the battery to hold a charge. After googling this method I appears to be a widely accepted practice.
So I couldn't resist trying it and felt i had nothing to lose. I am a DIY'r after all
I wore some eye protection and used lantern batteries wired in series. Before voltage surging the 12V packs read 6.5V and 5.8V on fresh charges. After voltage surging I charged the packs and they read 13.8V and 13.7V respectively. They both seem to work like new.
Now I'm wondering, if any of you have tried this method what type of success have you had? I'm wondering how long I can expect this fix to work. The fellow I got the info from said he's had fixed packs in operation for a couple of years and that this procedure can be redone several times before losing it's effectiveness.
Seems like a good way to get a few more years out of your old tools. Gonna try this method on a shark handheld vacuum that also uses NiCDs. Along with a 14.4 volt craftman drill/saw combo that my dad pawned off on me.