BC296D: Uniden BC296D LIPO/lithium ion battery mod

[flinx]

For many years I have been trying to find a solution to the BC296D Uniden battery pack (BP120 / BP150 / BP180 / BP250). Other battery packs that held normal AA batteries would not fit. The nicad/nimh battery tech made replacing the rechargeable batteries with something better (like Lithium ion) difficult. single cell lion bats put out a voltage of only 4.2v max, lower than the low battery voltage of a nicad battery pack.

most lion/lipo battery chargers only charged the battery and did not have an output voltage connection AND also would not fit inside the battery compartment. They would also require some kind of boost converter (taking up more space). The boost converter would increase the output voltage of the battery to at least 6vdc

Recently my intermittent (but relentless) searching finally found a combination of components that would fit in the compartment WITH a battery that was the same mah or higher than the nicad packs AND would have a service life longer than nicad/nimh.

for this mod you will need:
1 - J5019 combination 1S single battery charger/boost converter with built in BMS.

1 - LIPO battery pack measuring 10mm X 40mm X 50mm (thickness x length x width) or some type of lithium ion battery that will fit in the compartment with the other components and be of sufficient mah.

1 - DC barrel connector socket that will fit in the narrow confines of the side of the case.

1 - 5v-8v DC power supply.

The resolve to alter your scanner.

I removed the BMS from the LIPO battery though I do not know if that was necessary, but the BMS on the J5019 will take over for it. I was careful to insulate the wires with kapton tape.

I found a DC socket that just fit, carefully measured everything and found a LIPO battery that was 2400mah that also just fit. The boost converter/battery charger fit perfectly as well.

I used 3M 100mph double sided tape to hold the battery in. the BMS has 2 LED's on it a red one for charging and a green one for charged. it has a tiny POT to adjust the output voltage. I set mine to 5.99 volts because it was finicky. I reused the old battery packs connector.

the board is held in with hot glue. the BMS can charge at up to 1 amp. You can run the scanner while it is charging. I have not noted any interference from the boost converter (yet).

You cannot use the original power plug with this mod.

 

[dave3825]

Nice mod indeed. If it were me, I would swap the tape for Velcro and add a connector between the batt and the radio so a second charged batt could be swapped in if needed.

 

[flinx]

Nice mod indeed. If it were me, I would swap the tape for Velcro and add a connector between the batt and the radio so a second charged batt could be swapped in if needed.

I got this scanner from a thrift store for $3 I don't use it very often, so the old nicads were going bad even with charging them every 2 months. with this mod I should not need to replace the battery for about 10 years, and I am currently testing how long it runs. theoretically it should run for 18 hours on a full charge.

• Quiescent current: about 0.5 mA for the j5019 board

 

[dave3825]

I learned a long time ago that theoretically never really equals realistically. Still a cool mod and even cooler you picked up the radio for 3 bucks.

 

[flinx]

testing is complete. battery lasts 7.5 hours.
The radio draws between 140 and 190mah at 6v from the boost converter. that means that the boost converter is drawing 190-240mah at 4.2v from the battery, and 266-340mah when the battery is at 3v. the BMS seems to cutoff the voltage from the battery at about 2.7v which does not seem to be changeable.

I could probably get the battery to last longer if I had the boost converter output 5v.

 

[flinx]

do not remove the bms from the lipo battery this j5019 discharges the battery down to 2.5 volts.

 

[Ubbe]

The original battery probably used 4 cells at 1,2V each so you should be able to reduce the output voltage to 4,5V

/Ubbe

 

[flinx]

The original battery probably used 4 cells at 1,2V each so you should be able to reduce the output voltage to 4,5V

/Ubbe

the unit low battery beeps if you do that. there is a way to disable the low battery warning, but I'm not that concerned. I did lower the voltage to 5.