BC235 battery pack rebuild - max capacity?

[motorola_otaku]

Did a search & read the requisite stickies and didn't see this addressed.

I'm getting ready to rebuild the battery pack for a BC235XLT handheld and since hi-cap NiCD and NiMH AA-sized cells are so commonplace now I'd like to go bigger than the stock 800mAh. So my question is: what's the maximum capacity the internal charging circuit can handle? Insight from people who have done this previously would be greatly appreciated.

TIA

 

[ka3jjz]

There is no internal charging on the 235, AFAIK. There is (was?) a small charging tray that allowed you to charge the battery as well as run the scanner from AC. This is the way I have it with the somewhat newer 245. You have to be careful about running AC with the batteries installed - they will get VERY hot if done for a long time (I found this out the hard way). I suspect that the DC port is directly tied into the batteries somehow, and when there's no batteries, the connection is bypassed....

73 Mike

 

[jackj]

From looking at the user's manual on line, it looks like the scanner comes with Ni-Cd batteries. I would not recommend using Ni-MH cells in place of Ni-Cd cells. The charge characteristics are different and it would be possible to ruin Ni-MH cells pretty fast. The unit comes with a 800 mAh battery and using higher capacity Ni-Cd cells wouldn't hurt either the charger or the scanner but it would take longer to charge the battery. The 14 hour charge rate for Ni-Cd batteries is 0.1 C so your 800 mAh battery would require 80 mAh for 14 hours to fully recharge. If you use cells with a higher capacity then you would need to extend the charge time.

 

[motorola_otaku]

There is no internal charging on the 235, AFAIK.

No, the 245 definitely charges the battery pack internally; I had it apart yesterday to fix the antenna connector and saw what was probably a 5V voltage regulator electrically in between the 12V plug and the battery pack.

I would not recommend using Ni-MH cells in place of Ni-Cd cells. The charge characteristics are different and it would be possible to ruin Ni-MH cells pretty fast.

Interesting.. in the world of batwing products, NiMH and NiCd battery packs are interchangeable in legacy chargers.

Thanks for the input, guys.

 

[jackj]

Batteries

No, the 245 definitely charges the battery pack internally; I had it apart yesterday to fix the antenna connector and saw what was probably a 5V voltage regulator electrically in between the 12V plug and the battery pack.


Interesting.. in the world of batwing products, NiMH and NiCd battery packs are interchangeable in legacy chargers.

Thanks for the input, guys.

Yes but Batwing chargers are a little more intelligent than a simple voltage regulator and a current limiting resistor. You can trickle charge Ni-Cd cells but NiMH cells don't like to be trickle charged after they are fully charged. Also, you can't adjust the charge rate on your scanner. If you try to charge a 2500 mAh pack at 80 ma, it's going to take a week or more to recharge.

The owner's manual said to install the battery pack in the scanner and charge it for 14 hours before use. Sounds to me like it does have an internal charging circuit.

 

[DaveH]

There is no internal charging on the 235, AFAIK. There is (was?) a small charging tray that allowed you to charge the battery as well as run the scanner from AC.
73 Mike

Incorrect...the BC235 will charge directly from the AC adaptor. I had a pack built from 940mAh
NiCds, charges OK.

Dave