Batteries draining quickly

Status
Not open for further replies.

kc8syo

Member
Joined
Nov 20, 2004
Messages
162
Location
Fraser Mich.
I have a 396 that seems to drain my rechargeable batteries very quickly and thier fully charged after about 4 hours. Anyone else have this problem? The battery switch is set to nimh. TIA
 

firefgtr

Member
Premium Subscriber
Joined
Dec 7, 2004
Messages
530
Location
Welland, Ontario Canada
I had some cheap Radio Shack batteries in my 396T and yes they drained quickly, i switched the batteries to the more "pricey" Nickel-Metal Hydride batteries and they last 10 times longer
 

rfaricy

Member
Joined
Mar 8, 2004
Messages
150
Location
Gulfport, FL
If you're using the BCD396T to charge the batteries, there is absolutely no way a drained set of batteries will be fully charged within 4 hours. So no wonder you're not getting any life out of them.

Only when the display reads "charge complete" have the batteries been fully charged. The voltage display is not an indicator of the batteries' ability to hold a charge. Battery charge capacity tends to be negatively logarithmic as they lose charge ... So:
- While it might show "4.10" volts in the display after a 4 hour charge (mine does), it will quickly drop below "3.55" within an hour's use or so.
- Charge it for the full 14 hours, and it will show "4.10" volts off the charger, and won't drop to "3.55" until about six hours later.

Read your manual... the complete charge time for a drained set of cells is 14 hours. :roll:

You don't cook spaghetti for 5 minutes and expect it to eat right, even though it might look just as "bendy" as it does when it's done after 9 minutes, right?? sheesh
 
Last edited:

MacombMonitor

Member
Joined
May 18, 2005
Messages
3,551
kc8syo said:
I have a 396 that seems to drain my rechargeable batteries very quickly and thier fully charged after about 4 hours. Anyone else have this problem? The battery switch is set to nimh. TIA

Are you using a third party quick charger? If not, then I agree with rfaricy's post.

When I had my BCD396D, I was using a MAHA charger, and it would typically charge the batteries fully within 3~4 hours. They would run the radio under constant full time scanning for at least ten hours.
 

Codeman

Member
Joined
Aug 27, 2005
Messages
95
kc8syo said:
I have a 396 that seems to drain my rechargeable batteries very quickly and thier fully charged after about 4 hours. Anyone else have this problem? The battery switch is set to nimh. TIA

Check out Battery University for a lot of good info on battery technology and charging.
 
Last edited:

rfaricy

Member
Joined
Mar 8, 2004
Messages
150
Location
Gulfport, FL
If batteries are heating up, the cells are either not getting the proper metered amount of charge, or they're shot, or already fully charged. Batteries inherently convert charge to heat in these cases. Unfortunately, heat shortens a battery's lifespan.
 

firefgtr

Member
Premium Subscriber
Joined
Dec 7, 2004
Messages
530
Location
Welland, Ontario Canada
rfaricy said:
If you're using the BCD396T to charge the batteries, there is absolutely no way a drained set of batteries will be fully charged within 4 hours. So no wonder you're not getting any life out of them.

Only when the display reads "charge complete" have the batteries been fully charged. The voltage display is not an indicator of the batteries' ability to hold a charge. Battery charge capacity tends to be negatively logarithmic as they lose charge ... So:
- While it might show "4.10" volts in the display after a 4 hour charge (mine does), it will quickly drop below "3.55" within an hour's use or so.
- Charge it for the full 14 hours, and it will show "4.10" volts off the charger, and won't drop to "3.55" until about six hours later.

Read your manual... the complete charge time for a drained set of cells is 14 hours. :roll:

You don't cook spaghetti for 5 minutes and expect it to eat right, even though it might look just as "bendy" as it does when it's done after 9 minutes, right?? sheesh


on this point........can i leave the radio plugged in after the display reads" Charge Complete" or will the ruin the radio and/or batteries?
 

rfaricy

Member
Joined
Mar 8, 2004
Messages
150
Location
Gulfport, FL
Yep the charging circuit shuts off after "Charge Complete" appears. Your radio will be just fine (I leave mine plugged in for days on end).

It is a timed 14 hour cycle that resets everytime the radio is plugged in, so I wouldn't unplug it and plug it back in over and over ... But just leaving it is fine.

On this point, it would be nice to have it shut off when it detects a full charge, rather than a timed charge regardless of battery state. But I'm not sure a firmware update could handle that, as it's probably more intrinsic to the radio. It would be nice though.
 

firefgtr

Member
Premium Subscriber
Joined
Dec 7, 2004
Messages
530
Location
Welland, Ontario Canada
rfaricy said:
Yep the charging circuit shuts off after "Charge Complete" appears. Your radio will be just fine (I leave mine plugged in for days on end).

It is a timed 14 hour cycle that resets everytime the radio is plugged in, so I wouldn't unplug it and plug it back in over and over ... But just leaving it is fine.

On this point, it would be nice to have it shut off when it detects a full charge, rather than a timed charge regardless of battery state. But I'm not sure a firmware update could handle that, as it's probably more intrinsic to the radio. It would be nice though.
awesome!!! thank you:)
 

UPMan

In Memoriam
Premium Subscriber
Joined
Apr 19, 2004
Messages
13,296
Location
Arlington, TX
Detecting a full charge for NiMH batteries under C/10 conditions is nearly impossible when you are charging multiple cells. Each cell will reach the "full" state at slightly different times, so the change in charge slope will be almost non-existent. This is the main reason why the smart chargers out there all try to charge at a rate between C and C/4. They also detect charge full on each cell individually.

Note that NiMH batteries will always get warm during charge. This is normal. NiMH are exothermic during charge (unlike NiCd which are exothermic only during overcharge).
 

rfaricy

Member
Joined
Mar 8, 2004
Messages
150
Location
Gulfport, FL
You are correct sir ... I had a brain fart re: NiMH as being exothermic. And yeah I figured that about the charging deal, since it would be charging the cells in series and not parallel (and that's only the first hurdle).
 
Status
Not open for further replies.
Top