UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Re-stuffing HT batteries with PP3s

Mike. Watterson · 22nd Feb 2015, 5:26 pm

B126
I use one battery clip cut in half to join two sets of five PP3s. A second clip cut in half is used for the connections to socket. All but one type off PP3 I tried can clip to each other.

For other packs I use AAA or AA if they fit as they works out much cheaper per hour. Or some I use paralleled (using 1N4148 diodes to combine)stacks of CR2032 coin cells from China/Hong Kong (about 11p each inc postage). Note that as they have a better discharge curve that 79.5V (25 in series) is more than adequate for 90V pack, 38V (12 in series) for 45V and 60.5V (19 in series) for a 67V pack (terminal voltages via 1N4148 at 6mA to 10mA load, for 45V to 90V application).
For PP3 the 6F23 layer type is fine, the Alkaline only give about 60% more run tiime but do give x5 more shelf life.
CR2032 Coins are Lithium. They need to be parallel stacks as current per cell is limited.
The AAA and AA should be Alkaline, gives x5 to x10 shelf life and x2 run time at 10mA.

I try to fit a fuse. esp on AA and Lithium packs.

22nd Feb 2015, 5:26 pm	#27
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: Re-stuffing HT batteries with PP3s B126 I use one battery clip cut in half to join two sets of five PP3s. A second clip cut in half is used for the connections to socket. All but one type off PP3 I tried can clip to each other. For other packs I use AAA or AA if they fit as they works out much cheaper per hour. Or some I use paralleled (using 1N4148 diodes to combine)stacks of CR2032 coin cells from China/Hong Kong (about 11p each inc postage). Note that as they have a better discharge curve that 79.5V (25 in series) is more than adequate for 90V pack, 38V (12 in series) for 45V and 60.5V (19 in series) for a 67V pack (terminal voltages via 1N4148 at 6mA to 10mA load, for 45V to 90V application). For PP3 the 6F23 layer type is fine, the Alkaline only give about 60% more run tiime but do give x5 more shelf life. CR2032 Coins are Lithium. They need to be parallel stacks as current per cell is limited. The AAA and AA should be Alkaline, gives x5 to x10 shelf life and x2 run time at 10mA. I try to fit a fuse. esp on AA and Lithium packs.