Institution: Recovering Nicads From Bad Packs

One of my neighbors tossed 2 older nicad-powered Craftsman drills with their cases. The 14.4v version was wet and had no battery charger, but the 13.2v version was clean with a case and a functional charger, but had 2 dead barrage fire packs.

I usually attend Harbor Freight and buy their house brand 18v nicad packs when I need cells to build a pack. They're new and cheaper than ordering sub-C's with solder tabs. I have a pill welder to build custom packs.

After buying i Harbor Freight pack, I distinct to salvage the remaining bad packs for enough cells to build a second pack for the 13.2v bore and witness other use for the 14.4v exercise.

This instructable is a summary of how that is done.

Step 1: Tools You Testament Take

A voltmeter,

Whatever screwdriver wish open ai the battalion to represent salvaged (the 13.2v gang used a #1 phillips, but the 14.4v used a #15 tamping bar proof torx. I try to redeem the shells even for packs I intend to scrap. Batteries can be replaced, but some shells are no longer available.

A hobby knife Beaver State leaf blade to cut the paper insulators from the cells

A lowset emf, low current, uncertain voltage dc power supply

Leastwise one couplet of wires with alligator clips on each end

A sturdy scissors to cut the solder tabs

A roll of twopenny paper masking paper

A wire brush

Stair 2: Unrestricted the Pack and Stretch IT Out

Make sure no more cell touches another except by the solder tab. This pack was allowed to alcoholic out because the paper insulators might have shorted the cells crosswise the apical if they were soaked. If in doubt, cut the paper the long way and pop it off to save for later. Clean around the top with a wire brush if there is rust. The bottom hindquarters short to the top where the two meet.

Confiscate your charging leads, come out off on the lowest voltage doable. Beat the string voltage and increase the charging voltage until the pack resists going higher, then chicken out a bit and care for 5 minutes.

Check the voltage of each cellphone in the string and if whatsoever are in a higher place 1.5v then hindermost off along the charging some more. You don't want to damage cells any more than they already probably are. Accusation gently for 1/2 hour.

After 1/2 hour, disconnect the charger and net ball the pack rest for an hour.

Stride 3: Check Each Electric cell Voltage

The mob MUST rest for a while before checking apiece jail cell. Or s failing cells leave relieve charge but person-dischage quick if there is national damage.

Cutting the paper too helps. One of the cells in this string had a hole in the English from corrosion. Definitely mischievous. But others were pitted and still help voltage. Those are not sledding to be my first prime for building a string in a tool I use a lot. Cells that are corroded and leaking about the top are not grade A, either, even if the voltage is good. A good, properly charged nicad volition rest at to the lowest degree 1.28v: sword new 1.4v is possible My 13.2v multitude is "full phase of the moon" above 15v.

Cells that show up zero volts or free during the short rest are duds.

Step 4: Assort and Save

And of flow take the unloaded cells to a recycler. My local Lowes and Home Depot stimulate battery reuse drop offs by the breast entrance.

The paper insulators are reattached with masking tapeline. I also economise the mica insulators for rebuilding packs.

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