PRC-77 home made battery

[HMMWV]

So I got my first radio (military) and wanted to keep it looking intact even if I open the battery box. So for out of truck operation I needed to ditch the dry cell. Hence my newest project is using Black and Decker VPX lithium batteries. They are 7.0 volts so I'll be down 0.4 from the standard. But because I can get in theroy longer life and fast charge and only ~$14.00 for each (need two)! Used a sharp exacto like knife and cut open the old battery. Took out guts and made a plywoord box which fit in same space. Using spade lugs now I connect the two batts in series. Closed flaps on old cardboard cover and re-install. Want to add a fuse next time I open. The dual charger I have allows both batteries to be charged up at same time. If the testing works out as planned I'll post photos of construction.

So the drill,screw driver, flash light, etc all use the same batteries! I'm not stuck with a one application design which in the end is great. I only need to use batteries for hiking trips.

Anyone else make up their own?

Now I need to go find a 7777 inout power connector, found out after I got home the key way is larger! Bypassing it for now.

 

[Shieldwolf37]

Outstanding!
Try PRC68 ,com they have battery adapter cables for the 25/77 series radios.
For my GRR/5 I made a homebrew "A/B" Battery. The origional battery provided 1.5v for filaments and 90v for the screen. I use 8 D cells in parralell for thefilaments and 15-9volts in series paralell for the screen voltage. All of this fits in a WW2 British Bren gun mag pouch. I just use a quick disconnect inside the pouch for the GRR/5 battery cable.

 

[OPCOM]

Very good! the original batteries sometimes sold in various places are usually worthless except for such a mod.

Note for those with a PRC-25 - be very careful to supply the correct voltage of 2.5V to the 2DF4 tube. Mnay people use 3V (2 D cells), which is OK but not truly correct.

 

[scooter01922]

wow man, quick work, you just got that thing on friday Hope testing goes smoothly, i expect to check it out next time i'm in your neck of the woods or you are in mine. We can have a mini convoy.

 

[CGarbee]

Great to hear how folks are powering these things these days.

I went the "easy" route and purchased one of Bruce Clarke's (PRC68"s) setups for each of my PRC77's and I really like them a lot... Very well put together, use D cells, and have a plug on them so that you can use the block to bench power units and/or power other electronic devices... I also snagged one of his front power cables so I can power the radio from my 12v vehicles as well...