DEWALT326 Today Only

Tip of the day. Higher current rated batteries for cordless tools seem to produce more power in tools that need it. Circular saw, angle grinder, saber saw, and even cordless chainsaw perform better with the 8ah batteries. I don't mean just longer. I mean better.

Ah-yup. That's pretty much the way I figured it worked. I was a little surprised at how well it works the first time I slapped a bigger battery on my DeWalt 20V angle grinder. Still not the power of a real corded angle grinder, but adequate for lots of outdoor jobs that don't justify stringing out an extension cord.

Ah-yup. That's pretty much the way I figured it worked. I was a little surprised at how well it works the first time I slapped a bigger battery on my DeWalt 20V angle grinder. Still not the power of a real corded angle grinder, but adequate for lots of outdoor jobs that don't justify stringing out an extension cord.

-- Bob La Londe CNC Molds N Stuff

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My experimenting with cordless tools and batteries has been hindered by the difficulty of making non-destructive electrical connections. I can measure and record charging voltage by tapping into the charger, but not charging or especially running current without adding resistance that changes it. Connector geometries can be difficult to copy accurately enough in wood or plastic, and need solid attachment to test at full load. Maybe 3D printed adapters would help.

Silicone insulated wire is very nice if I can find a place to attach it:

Most semi pro / DIY pack builders spot weld connections. The big issue is that even pretty good guys smoke a few cells doing it. That being said nondestructive removable connections could be an issue, but adding tabs for measurement that you can insulate when not in use might not be impossible. An alternative to cutting into a pack and possibly destroying it might be to use one of the cross brand (or older model of the same brand) battery adapters and cut into that between the battery and the tool instead.

The other alternative with a lower degree of precision, but not invalid or merely anecdotal is observed performance (work performed). Observational or survey only research is not invalid data gathering if there is a sample size large enough to satisfy the observer and/or relevant parties. Its just has a lower degree of precision than a proper testing protocol.

I don't know where they shipped from, but dang that was fast. The two new batteries are on the chargers already.

Most semi pro / DIY pack builders spot weld connections. The big issue is that even pretty good guys smoke a few cells doing it. That being said nondestructive removable connections could be an issue, but adding tabs for measurement that you can insulate when not in use might not be impossible. An alternative to cutting into a pack and possibly destroying it might be to use one of the cross brand (or older model of the same brand) battery adapters and cut into that between the battery and the tool instead.

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Stripping a dead battery sort of worked to bring wires out of the tool handle, the problem is the contacts are attached to cells instead of the plastic.

The task wasn't worth much effort. I bought two aftermarket NiMH batteries and a NiMH charger instead of fussing with rebuilding and resealing the dead NiCads, and they have held up well enough for my light use.

The voltage and thermistor measurement points are banana jacks added to the charger. I wanted to see how the cheap charger determines the NiMH fast charge endpoint. It simply cuts off just below the maximum allowable voltage, around 22V for a 14.4V pack. I could see the 5mV steps as each cell reached full and began generating oxygen but the charger ignored them. That endpoint makes more sense for fast charging single cells.

In industry I worked mainly with lead-acid and lithium instead of NiCads.