Tuesday, January 16, 2024

Powering a QRP radio for portable operations with a Powertech battery inverter

I was looking around for a nice way to power a small radio when operating in the field. I have various batteries but nothing in a convenient box. A solution was right under my nose! I have a little (155Whr) Powertech rechargeable battery. It has USB outputs and a 240V "modified" sine wave inverter. This will run a Dometic fridge in the car during a trip to the supermarket to get frozen food.

It also has three 2.1mm coaxial sockets marked "DC Output 12V" and I wondered if these were fed by a buck converter and might be noisy. It turns out there is no noise on these DC outputs.

The box has these specifications:

I thought I'd have a peek inside partly to see if the markings on the battery match the claimed capacity. It's fairly straightforward to open except I think the bottom screw might have been glued in. Obviously a unit that generates 240V is potentially dangerous.

The unit is a quality construction from what I can see. The battery pack is made up of 18650 cells.

Markings on the battery pack match the claimed capacity. The voltage is marked as 11.1V but when fully charged I see 12.4V so it's likely that a radio powered by this would need to be able to work well below 12V.

This unit is an old model and the new version has a USB-C output, although I wonder if it's USB-C PD?

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