Two lower corners marked for PSR-2
The insulating cup is to prevent reverse polarity installation of a battery on the radio. But two batteries can be shorted together or two radios can mate. This also means the battery adapter can be used as the top of a battery box.
This adapter comes with a printed circuit board that has snaps to hold either:A small modification of the printed circuit board needs to be done by the user to fit the PSR-2 battery compartment. The latest version has the radius lines marked for easy filing of the corners needed.
2 each 9 Volt batteries
4 each 9 Volt batteries
1 each battery holder that has 10 each AA batteries
1 battery holder for 2 ea. AA batteries with a gimmick to electrically insert them in series with the 10 AA batt.
4 screws to mount the PCB to a PRC-68 family radio
4 foam packing strips to fill up the space in the battery box
Can use 9 volt or AA batteriesThe batteries can be primary or rechargeable.
10 each AA 12 each AA
2 each 9 Volt 2 each 9 Volt 4 each 9 Volt
Safety Insulating Sleeve on Negative TerminalThere is an insulating sleeve around the negative terminal to prevent connecting two batteries in a way that would cause a short. This insulator also prevents touching the radio with reverse polarity.
The amp hour capacity of the adapter depends on the type of batteries used. Some examples might be:
# Chemistry Battery Model Volts Amp hours Watt hours
2 * 9V Alkaline Rayovac A1604 18 0.6 10.8
2 * 9V NiMH Eveready NH22 15.7 0.175 2.8
4 * 9V Alkaline Rayovac A1604 18 1.2 21.6
4 * 9V LiMnO2 Energizer L522 18 2.4 43.2
10 * 1.5V NiMH Maha 2700 13.6 2.7 36.37
10 * 1.5V Alkaline Rayovac 815 15.8 2.2 34.8
10 * 1.5V LiFeS2 Energizer L91
15.0 2.9 43.5
Using 12 instead of 10 AA batteries will not change the Amp hours, but it does increase the talk time because the cutoff voltage is increased. For a comparison to the military batteries see my PRC-68 Family Batteries page.
17 Aug 2003 - the above table is based on the manufacturer's data sheets. The capacity (amp hours or watt hours) increases if the current drawn is lower that that used by the manufacturer when they tested the battery. I tested 8 each Powerex AA cells marked 1.7 Amp Hours using a simulated PRC-126 i.e. receive mode with no audio for 9 minutes at 40 ma and transmit mode for 1 minute at 350 ma. This cycle was repeated until the battery voltage went below 10 Volts (low battery tone voltage). The 10 cells (typo on the screen shot says 8 cells) put out 7.9 AH, they lasted for 22.4 hours.
19 Aug 2003 - Tested 10 each EverActive AA cells, 24 each blister packed at Wal Mart for $7. Date code: DEC 2009. UPC: 81131 74129. These lasted for about 24 hours using the same load as above and a 10 Volt cutoff voltage. The screen shot shows 10.6 AH, but this is for a cutoff voltage of 8 Volts. Using a linear interpolation gives about 8.4 AH to 10 Volts, so these low cost AA cells don't have much more than the 1.7 AH advertised capacity of the above Powerx AA cells. Note that the voltage difference between the Rx condition and the Tx condition increases substantially the battery runs down. When the battery reached 8 Volts the internal resistance of the pack was just over 10 Ohms. After the test stopped and the battery had time to recover the terminal voltage climbed back to 12.3 Volts (1.23 Volts per cell) for dead cells.
Maximum Safe Battery VoltageI have not done a test by burning out a radio so this is my best guess.
Some of the manuals show a 17 Volt Zener diode protecting the radio when external power is applied. But a Zener does have some internal resistance so does not really provide a solid 17 Volts, so a little above 17 Volts may be safe.
Also, it depends on the batteries you use and how many. NiCads and NMH batteries have a lower voltage than Alkalines.
you can safely use 12 NiCad or NMH batteries, but 12 Akalines may be too much. Alkalines are about 1.5 * 12 = 18 Volts just a little too high.
Has a BNC(f) jack to allow easy connection of external antennas. Also has a built-in DC return so open circuit antennas can be used with the PRC-68B, PRC-126, PRC-128 and PRC-136 radios.
The Squad Radio Battery Snap is also for sale as a seperate product. This can be used either to power a squad radio through the battery terminals or as a snap to charge Squad Radio Batteries.
created 21 August 2001.