The thought had crossed my mind. How long have you been doing this?
BC125AT: BC125AT - How to Deal with Overcharge Hazard.
- Thread starter Samyham
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The thought had crossed my mind. How long have you been doing this?
My 245XLT has been on and connected to power with the Ni-MH batteries in it for years and the batteries have never blown up and still power the scanner if I disconnect power.
wtp
Member
i did not worry about heating up the radio i bought in 2007 (bcd396t).
i worried about lightning and having a $500 radio get zapped. i live in Florida.
so i paid about $70 for the charger.
and at the time i did not have a steady job, but still bought it.
and the wife bought a 396xt and used to charge the batteries in it as she wanted to grab and go with it.
one day she noticed it was a tad 'warm' and that was the last day she plugged it in.
so the odds of an overheated radio happening is probably next to zero.
but in Florida the odds of lighning i very high.
i worried about lightning and having a $500 radio get zapped. i live in Florida.
so i paid about $70 for the charger.
and at the time i did not have a steady job, but still bought it.
and the wife bought a 396xt and used to charge the batteries in it as she wanted to grab and go with it.
one day she noticed it was a tad 'warm' and that was the last day she plugged it in.
so the odds of an overheated radio happening is probably next to zero.
but in Florida the odds of lighning i very high.
RU55
Radio receiver
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- Jul 25, 2022
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What I unusually do when I run my BC125AT at home or work powered by a USB battery pack, is remove the batteries from the unit. I don't charge the AA cells in the unit because an external charger is much faster. I use Eneloop batteries and a Maha MH-C9000 charger. No problem with over charging the batteries.
24/7 for several years with three 125A. Well, one in the vehicle is not 24/7.
Sounds promising. I'll test it out. For other viewers: since the rechargeable NiMH voltage is lower than the alkaline, there won't be harm to the scanner. Also, the charging timer does not come on in Alkaline battery mode (of course). I see Vagrant has been doing this for a long time and makes no mention of any significant performance problems or with an over-draw problem on the lower voltage batteries. I know I'm using the wrong terms but I am not an expert in these matters.
The UBC125XLT charging circuit appears to be current limited by an 8.2 Ohm 1W resistor from the USV 5V supply.
USB power at 5V. Battery voltage is 2.4V nominal so current = 320mA. Resistor dissipation = 0.8W
USB power at 5V. Battery voltage at 0V nominal so current = 610mA. Resistor dissipation = 3W
With those basics it is a little more complicated as far as I can tell. There is a transistor to switch the charging On/Off according to the timer. There is also some other monitoring circuitry driven by the processor. This may or may not allow for over current detection. Had to tell.
It the case of putting an Alkaline battery in on the NiMH setting then when 5V USB is applied my UBC125XLT comes up "Battery Error"! and no charging current appears to be present. If I put just one alkaline battery in the on a digital volt meter the current is modulated and on an analog meter approx. 300mA.
Removing batteries and shorting delivers no current.
So the circuits seem quite safe.
So in conclusion the safest way to use the BC125AT is to 'turn off' the charging timer by keeping the BC125AT set on the Alkaline setting regardless of batteries you use. Vagrant says he does that and he's been around quite awhile.
The second safest way is the way I am going with until I learn better and that is to get into the habit of often checking the charging timer setting and making sure it is set to the lowest setting of 1 hour.
Finally, not related to safety, if anyone has experienced accidentally using alkaline batteries while the BC125AT is set on the NiMH setting please post in this thread the consequences of your error which hopefully will be nothing or not much.
Thank you all for answering my concerns so well. Best wishes to all. 73
wtp
Member
you might get a quicker answer if you make a new post about it.
Just leave the switch set to alkaline, buy some good rechargeable batts and charge them in an external charger.
Skip the second way and stick with the first. Then there's no learning and no forgetting 1 hour charge settings. I have a Br330T with the same switch and its been set to alkaline since the day I got it. The charge circuit has never charged any batts in that scanner. I only use rechargeables in my 436 and never let it charge.
Skip the second way and stick with the first. Then there's no learning and no forgetting 1 hour charge settings. I have a Br330T with the same switch and its been set to alkaline since the day I got it. The charge circuit has never charged any batts in that scanner. I only use rechargeables in my 436 and never let it charge.
Who am I, a rookie, to argue with 2 very experienced guys?
Thanks Vagrant and Dave3825.
This is what I do with Scan125. Every time the program starts it tells you what the charge condition and voltage of the batteries is. It also monitors the voltage with a period set by the user in the options.
I covered this in my post above (for the UBC125XLT) and the scanner display gives "Battery Error" and no charge is delivered. This you can easily check yourself without damaging either the scanner of the battery.
Pass as I've not done any detailed testing on this. The battery voltage is still available info to the scanner and Scan125 and Scan125 Voltage/Charge indicator is more aligned to NiMh 1.2V nominal and 1.4V fully charged levels and does not know about the battery switch position.. Good new alkaline batteries are going to be in the 1.5V region.
I just checked somethings again. Results:
1) Alkaline batts installed properly with charging cable attached: screen shows 'Charge Off'.
2) Alkaline batts installed wrong (NiMH setting) with cable attached: Screen read 'Charging' for well over 1 minute before changing to show 'battery error'. Alkaline batteries were not hot.
3) Alkaline batts installed wrong as in 2), scanner turns on. I ran it for 2 to 3 minutes in search mode. Used Hold to listen to transmissions. All seemed OK. I just hope I haven't damaged circuits in some way and find out later.
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The 125 can chew down a pair of Nicads really quick. I've always been fond of the Enegizer Lithium rechargables. I have the 4 pack with the external charger.
They have very good, controlled recharging weather you're charging all 4 or just two at a time and I just leave the scanner in alkaline mode.
They have great run time even with a busy scanner.
I went so far as to get a second charger and additional cells, both AA and AAA. I used them in my camera flash, drone remote, digital recorder and my Cree LED flashlight.
They're a good investment!
They have very good, controlled recharging weather you're charging all 4 or just two at a time and I just leave the scanner in alkaline mode.
They have great run time even with a busy scanner.
I went so far as to get a second charger and additional cells, both AA and AAA. I used them in my camera flash, drone remote, digital recorder and my Cree LED flashlight.
They're a good investment!
On page 23 of the BC125AT manual it specifically states that it may cause a safety hazard to use Ni-CD batteries. I'm not sure about the Lithiums or what you mean by '4 pack'.
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