396T Battery problem

[rescueone]

I have a strange problem with my 396T running on batteries. I've always charged the batteries in the radio and have never had a problem, untill now. The "low battery" indicator and "beep" won't go off. The batteries are fully charged, and will last 8 hours with continuous use, but the low battery indicator and beep are constantly on and won't stop untill I plug it into the charger. Another battery related problem is with the backlight. I have the light set on "infinite" If I'm running on batteries as soon as I turn on the backlight, the radio shuts off, like the batteries are dead. If I turn it back on and leave the light off, it keeps working, although the above mentioned problem still exists.
Anybody else run into this and maybe know a cure ? Think it's time to send it to Uniden ? Radio was purchased, used, in 08 and has been fully functional until now.

 

[jackj]

It sounds like you have a bad battery. The light draws the battery voltage down below the point where the radio quits working, that's why it goes dead when you turn the light on. As for running for 8 hours with the low battery indicator on, maybe a dead cell causing the battery voltage to be below the trigger point. I'll bet if you replace the battery, the problems will go away.

 

[SCPD]

I have to agree with the above post, replace the batteries and see what happens.

 

[rescueone]

It,s NOT the batteries (they have been checked with a voltage meter) it's a problem with the radio.

 

[LordJ]

A voltage meter will not necessarily show a problem with the battery or fast discharge problem. I would also replace the batteries. I would start by using Alkalines for a complete cycle, with the switch set to Alkalines.
On another note, you are asking for help, actually try the suggestions that you have been given before blowing it off, and you might be surprised. If you aren't willing to at least try suggestions people offer, people will just stop giving you suggestions..it's pretty much the way help forums work...good luck, and hope you find the issue.

 

[ilgrant]

It sounds like the batteries aren't working when it's in a 'load' condition. The radio is considered the 'load'. After a certain period of time the batteries can't hold as much charge as they used to causing the problem you are seeing.

A difference in quality of the batteries could result in one battery holding more charge than the other. When placed under a heavy load condition (light on, high volume) the radio will either beep (low battery) or shut down by the low battery circuit.

While the battery may appear good with a voltmeter out of the radio that may not be the case when it is in the radio (which is a better method of testing them). Do to the difficulty in trying to measure the batteries in the radio it is much simpler to replace the batteries.

 

[CompuDoc]

The batteries might show good with a volt meter but still be bad because the volt meter is hardly putting a draw on them.

Think of this scenario, you have a car with a 12 volt battery that does not turn over. You take your meter out and the battery is showing 12 volts. You then leave the volt meter on the battery and have someone try to crank the car and the voltage right away drops to 8 volts. That is because two things are going on. Your putting a draw on the battery and voltage would normally go down while the draw is present. The draw meaning the starter, however even though the voltage might have drawn down their is not enough amperage for the load in the battery and that is why the car will not turn over.

If you take a car to a garage to have them check the battery the mechanic will load test the battery. He will not just put a meter on it to check the voltage but he will also put an amp meter on it and draw it down over a certain period of time and if the battery is drawn down faster than the allotted time the battery needs to be replaced.

The same thing goes for your scanner. They draw on the batteries and if the batteries cant keep up with the demand the battery's need to be replaced. Those batteries that your having a problem with may work well in a remote control because a remote control has less of a draw on the batteries than your scanner does.

 

[scanrfan]

BC396T Battery Problem

You can try taking a fresh/good set of batteries and replace the old set one at a time to try and identify the "weak"/"bad" battery. Replace one of the old batteries with a good/fresh battery - if the scanner works o.k. then that battery "may" be good. Put that battery back in the radio and remove another old battery and replace it with the new battery. Repeat this until you identify the bad battery. However, the best thing to do is replace "all" the batteries with fresh/good batteries. By replacing all the batteries with fresh/good batteries you know the radio should work properly and have a longer "on" time for listening.

 

[ka3jjz]

I've had the famous beep happen in the 396 when I knew the batteries were still good - and just recently I had one cell evidently go bad only after an hour or two of use - I simply recharged another set and all is well.

There is a well known bug with the 396 - it tends to show a low voltage condition even though there is plenty left in the battery. It's a design fault, and I have never understood why the various beta testers didn't file a report on this when the radio was under test. A VOM is still going to show the battery is good - and it's likely to be correct. Besides, a VOM cannot measure whatever capacity is still in the battery.

In addition, you should never depend on a long term charge of the batteries in the 396. There's no way to control the current, no thermal sensing - and I seem to recall when the radio was first out, that more than a few folks cooked their batteries if you left them in to charge for too long. That's why most people I know that have the 396 also have a separate battery charger which properly conditions NiCd cells - just recharging them time and again is totally wrong, particularly since there's still a lot of juice left in the cells, even though the 396 says otherwise.

I think the XT models are a bit better on this, but to me, Uniden models have a nasty flaw when it comes to understanding battery charging and requirements. There are many 3 cell chargers on the market these days, and it shouldn't be all that big a deal to incorporate the circuit design into a future scanner. Of course, we haven't even mentioned the extra instructions that must be stored in the EEPROM, but to me that's not the real issue.

Bottom line - don't waste your time sending the radio back, if you were contemplating doing that. There's nothing wrong. Get a decent external battery charger. 73 Mike

 

[rescueone]

Thanks to all who offered detailed explanations and your personal experience with the 396. I have half-solved the problem. Seems like I have 2 problems. 1 battery did appear defective. With that 1 battery replaced, the radio no longer shuts off when the light is activated, however, even with 3 new fully charged batteries installed, the "low battery warning" continues to sound. Guess I'll just shut off the beep and live with the flashing icon in the display.

 

[Tsch6373]

I wouldn't bother with ni-cads anymore. I have the separate charger and 3 sets of 3 Nickel-Metal Hydrides. The don't get the memory effect that the nicads do if they're not fully discharged. I change the batteries after a day's use to fresh ones that have been in the charger. My battery of choice is the new DuraCell 2650mAh. That's the highest mAh rating I've seen for AA batteries. They power my scanner for the full 10 hours that I'm on the road (used with an earphone) and then for several more hours at home on my nightstand. Also, if you've been using your batteries for a year or more, I wouldn't bother trying to find the 'bad' battery, just replace them all at the same time.

 

[ilgrant]

Does the voltage on the display read less than 3.6 volts?