396T Battery Life

[rangers38]

I have had issues regarding battery life in my hand held scanner. Purchased several kinds of rechargeable
AA batteries and same results. I have been using NIMH batteries, 2000 NIMH, 2600 NIMH, just purchase 2900 NIMH batteries. After 5 hours use the batteries have gone dead.I had the unit on during that time but had limited communications so the drain over that period should not be that great. Anyone have any ideas on who to extend the battery life so you can get more usage on the unit before a recharge is required?

 

[W6KRU]

If you recharge batteries in the scanner, you can expect dismal performance, no matter which batteries you buy. I had to learn this the hard way. The scanner is a very lousy charger and you risk destroying the scanner with overcharged or defective batteries.

 

[rangers38]

i usually recharge the batteries in the scanner, but with the new ones i am using a separate battery charger unit. I just don't get why the battery life is so short with this scanner. Did you have damage done to your scanner using the scanners AC charger??

 

[W6KRU]

No. Never damaged the scanner. I just went through several sets of batteries that had very short lives. Other people have seen the damage caused by overheated batteries. I did see my scanner lock up a few times that I now attribute to hot batteries in hindsight.

 

[jpinches]

Battery Charger

I have had issues regarding battery life in my hand held scanner. Purchased several kinds of rechargeable
AA batteries and same results. I have been using NIMH batteries, 2000 NIMH, 2600 NIMH, just purchase 2900 NIMH batteries. After 5 hours use the batteries have gone dead.I had the unit on during that time but had limited communications so the drain over that period should not be that great. Anyone have any ideas on who to extend the battery life so you can get more usage on the unit before a recharge is required?

Just went through the process of figuring out how to get more life out of my batteries. I started with Duracell 2650mha and discovered my old 4 channel 1 hour charger wasn't charging them to full capacity. After I borrowed my friend's trickle charger, the run time went from 4 hours to 8+ hours with constant scanning, MOT 1 and 2 systems scanned and 95% open squelch time. I ordered a new 4 channel charger that is rated up to 2800mha batteries and a (12) 2600mha for around $30 on-line. With the new charger, I am running 8.5 hours with same scanning conditions plus the back-light set "on" with low dim / squelch settings. So the new charger is doing much better at charging then either my old charger or my friend's - plus it finishes charging in 2 - 2.5 hrs. Keep in mind that rechargeable batteries don't reach full capacity till after 3-5 charges. Try a new charger rated for your battery capacity and cycle them several times before judging. You should be able to get at least 8 hrs constant run time under your limited activity conditions.

 

[W9NES]

Do yourself a favor.NEVER CHARGE THE BATTERIES IN THE SCANNER.As the others have posted charge the batteries in a charger like the Lacross Charger that I bought and use the 2900Mah batteries. Run the batteries all the way down before charging them .I charge my batteries at 200 on the charging rate and I have excellent results.I do this both for my Uniden 396T and my Uniden 396XT.---Tim DeLong W9NES/GMRSKAF3207/*Monitoring all of Metro Indianapolis and Marion County along with all of Central Indiana and The World from *The Northwest Commications Center*

 

[GTO_04]

Charging the batteries in the scanner is like playing with fire. There is no other charge termination other than a simple timer, and you run the risk of over- or undercharging your batteries. Should the batteries overheat, I would much rather damage a $40-70 battery charger then a $500 digital scanner! And normally
a dedicated charger will sense a defective battery and not try to charge it.

You will get the best capacity out of your batteries if you use a charger that uses independent charging circuits for each cell. The LaCrosse charger is one of them. I use the Maha MH-C801D and have been very happy with it.

GTO_04

 

[W9NES]

Thanks GTO_04 For your input.

 

[fullmoon]

Thanks for the tips..I just bought a 396XT and realized I need to get an external battery charger..Any stores that I could buy one at??I think Walgreens has them...

 

[jackj]

The problem with most of the commonly available chargers is that they only monitor cell temperature, if they monitor anything. A lot of them only time the charge and those will consistently either over or under charge the cells. You need a charger that is programmable and monitors both cell temperature and cell voltage. I use the PowerEx 4 slot AA / AAA charger and it seems to work great.

 

[W6KRU]

I really like this charger. It is 4 channel, programmable, and has a refresh mode that charges, discharges and then recharges again.

MAHA MH-C9000 Advanced Battery ChargerFree Deluxe Storage Ca..

 

[rangers38]

What would be the best/economical 4 battery charger for 2900mah NIMH batteries and where would be a good online site to purchase?

 

[rangers38]

Battery Charger

Purchased a PowerEx MH-C9000 Charger/Analyzer and 4 new 2900 MAH NiMH batteries. Put the new batteries through the break in mode where charger charges/discharges and cycles the batteries to break in new batteries. After about 40 hr. they were done. Put them in my 396T got about 3.5 hrs out of them before they went dead. Any suggestions?

 

[jackj]

Huh?

Purchased a PowerEx MH-C9000 Charger/Analyzer and 4 new 2900 MAH NiMH batteries. Put the new batteries through the break in mode where charger charges/discharges and cycles the batteries to break in new batteries. After about 40 hr. they were done. Put them in my 396T got about 3.5 hrs out of them before they went dead. Any suggestions?

According to your figures, you 396T pulls about 800 ma. That current draw seems a little high. Either your 396T has a problem or your cells are not really 2900 mah cells. Put your cells through a "Refresh / Analyze" and measure their real capacity. Set your charge rate at the 16 hr rate which is usually 0.1 times the cell capacity. Set your discharge rate the same. However read the small print on the cells, they will usually list the 14-16 hr charge rate. I have some AA cells that say in big print "2500 mah" and then in small print elsewhere on the cell "Standard Charge: 14-16 hrs x 220 ma." That would seem to imply that my cells are really 2200 mah cells.

BTW Ni-Mh cells really don't need a break-in like NiCd cells.

 

[rangers38]

The batteries only say 2900 MAH nothing else they are Maximal Power batteries. I followed the directions with the charger for NiMH batteries. I will try to put them back in and use your directions and see what happens. These batteries are brand new, I also bought another set last week which is in the charger now. I agree could have a bad battery or so but i now have 8 of them so I would think most of them would be good?

 

[rangers38]

jackj- I treid your suggestion with the batteries. Put all 4 in the charger in refresh/analyze mode. The charge rate goes to 2000mah, and the discharge rate 1000mah. That is the limits for the charger. I set the charge rate at 2000, discharge 1000. After the cells were charged the display says about 1400 mah 160 minutes. Does this seem correct/ for 2900 Mah batteries

 

[jackj]

Charge rate

jackj- I treid your suggestion with the batteries. Put all 4 in the charger in refresh/analyze mode. The charge rate goes to 2000mah, and the discharge rate 1000mah. That is the limits for the charger. I set the charge rate at 2000, discharge 1000. After the cells were charged the display says about 1400 mah 160 minutes. Does this seem correct/ for 2900 Mah batteries

You should charge them at 0.1 C (C=cell capacity in milliamp hours). So a cell that is listed as 2900 mah should be charged at 290 ma. Put them back in and program the charger to charge them at 300 ma and discharge at 300 ma. The cells should be pretty close to fully charged right now so the initial charge won't take very long. Your first test was not a valid test of the cell's capacity unfortunately. The discharge time vs current isn't linear and higher discharge rates actually reduce the total amount of power the cell can deliver.

 

[rangers38]

jackj- thanks for your help, will try your advice on the charge rate and let you know how it works.

 

[LordJ]

I would suggest buying Alkaline Batteries, one set of Energizer and one set of Duracell. See how long those last, then it should be easier to see if the issue is Battery or Radio. It seems like alot of attention to the Battery, but not the radio. How many systems are you scanning, are you running the radio full volume, backlight on, CC on.. etc.

 

[rangers38]

Currently only using banks 1& 2 on scanner. Conventional channels on one trunk band on the other, no back
light, volume half way.