this I got to brand, maybe as the "GR-P Powerbank"
so... this has been an evolvement of my former design.
This was a battery case with 4 18650 Lithium-Ion batteries wired 2s2p and feeding 7.2 (8.4)V to the radio through dummy batteries in a AA battery case.
This one goes one step further.
It uses 4 18650s of a working voltage of 16.8V and a step down DC-DC converter set to output 13.2V.
The converter is thermally on an aluminum heatsink with its fins outside the powerbank.
A LED indication light will be added as soon as I calculate the forward volatge of those I have and find the proper resistor.
My Kenwood TH-F6/7 radio (and the Wouxons too) can take car battery DC voltage AND operate with it.
Most significantly when the radio is operated by such voltage the medium power setting becomes 2watts from the original 0.5W!
Powerbank capacity depends on the batteries of course. the ones used are 3100mAh ones but you can get as high as 3500mAhs these days. Speaking in watts that is 44W exactly four times the radio's battery power.
A side benefit is that the radio is also charged when not in use, and fast charged too.
Working current is 2A according to the original Kenwood accesory specs, so we are good on various parameters.
Batteries are charged independently outside the case of course, and are matched cos 4 lithiums in series is not that good idea.
that is all, if you like it wait till I receive the parts for my next project..
