TRX-1: Internal Charging of NiMH Cells

[N6HHR]

Greetings,

I would like to figure-out how long to charge a set of NiMH cells inside my TRX-1. There is a setting to have the internal charger circuit automatically shut-off after xx hours. I have a new set of 2700mAH NiMH cells on board. Assuming they're discharged to the point where the low battery indicator (beeps and 'empty' cell icon) comes on, how long should I let the charge circuit run?

(I could figure this out if I knew what the charge rate is, but I don't see that in the specs.)

TNX de N6HHR

 

[RaleighGuy]

Greetings,

I would like to figure-out how long to charge a set of NiMH cells inside my TRX-1. There is a setting to have the internal charger circuit automatically shut-off after xx hours. I have a new set of 2700mAH NiMH cells on board. Assuming they're discharged to the point where the low battery indicator (beeps and 'empty' cell icon) comes on, how long should I let the charge circuit run?

(I could figure this out if I knew what the charge rate is, but I don't see that in the specs.)

TNX de N6HHR

From experience, they do not charge well inside a TRX-1, and if charged and left in the scanner while on AC power they drain. Use an external charger for best results.

 

[pb_lonny]

100% charge them externally....

 

[jaspence]

GET AN EXTERNAL CHARGER! A short melted one of my scanners due to a battery that shorted a few years ago while charging internally. There are many threads on RR about this and why it is a much better way.

 

[wtp]

i got up on the box and sent him a wordy PM about it.
N6HHR, look to the top right of this page for the envelope.

 

[N6HHR]

Thank you all, gents, for the responses. I do get it that, once you've destroyed a nice radio via a charging mishap, you'll never use internal charging again. And I thank the guys who have provided this admonition.

But I'm gonna be pig-headed about this one and go ahead with internal charging anyway. Damn the torpedoes ...

I measured the internal charge current of my TRX-1 with 2700mAH NiMH AA cells by 'tipping-out' one of the cells and placing my meter probes in series with the cells under charge. Using a typical 5V 1.0A 'wall wart' USB charger, and the cells at about 50% discharge, I measured a charge current of 45mA. That's a very low charge current - even lower than what is considered to be trickle charging. An online charge calculator says, assuming the cells are 80% discharged, that it would take 60 hours (that's two and a half days) at this rate to fully charge these cells.

Whistler's EZ Scan software allows setting the amount of time the internal charge circuit will run (Advanced Features > Battery Options) anywhere from 1 to 98 hours, after which the charge circuit is turned-off and a "charge complete" message shows on the radio's display. I had been allowing 16 hours of charge, and only getting about 4 hours of operation before the low battery warning sounds. Armed with the above data, I'm going to increase the charge time to 32 hours and see if there's any improvement in run time.

(Side note: The Charge Hours setting can be different in each V-Scanner folder in the program. If you use multiple V-Scanner folders, like I do, check the Charge Hours setting in each V-Scanner folder.)

And if I have a charging mishap and destroy this nice radio, I'll at least man-up and admit it. I have been warned.

73, David, N6HHR

 

[Wackyracer]

Thank you all, gents, for the responses. I do get it that, once you've destroyed a nice radio via a charging mishap, you'll never use internal charging again. And I thank the guys who have provided this admonition.

But I'm gonna be pig-headed about this one and go ahead with internal charging anyway. Damn the torpedoes ...

I measured the internal charge current of my TRX-1 with 2700mAH NiMH AA cells by 'tipping-out' one of the cells and placing my meter probes in series with the cells under charge. Using a typical 5V 1.0A 'wall wart' USB charger, and the cells at about 50% discharge, I measured a charge current of 45mA. That's a very low charge current - even lower than what is considered to be trickle charging. An online charge calculator says, assuming the cells are 80% discharged, that it would take 60 hours (that's two and a half days) at this rate to fully charge these cells.

Whistler's EZ Scan software allows setting the amount of time the internal charge circuit will run (Advanced Features > Battery Options) anywhere from 1 to 98 hours, after which the charge circuit is turned-off and a "charge complete" message shows on the radio's display. I had been allowing 16 hours of charge, and only getting about 4 hours of operation before the low battery warning sounds. Armed with the above data, I'm going to increase the charge time to 32 hours and see if there's any improvement in run time.

(Side note: The Charge Hours setting can be different in each V-Scanner folder in the program. If you use multiple V-Scanner folders, like I do, check the Charge Hours setting in each V-Scanner folder.)

And if I have a charging mishap and destroy this nice radio, I'll at least man-up and admit it. I have been warned.

73, David, N6

You were given great advice.... to sum it up, The scanner sucks at charging.

I use panasonic enloops and a external charger/conditioner

 

[jaspence]

Internal charging in any device should be avoided if possible. Several of my HTs have charging plugs or extra cost external chargers, even for removable battery packs. Go external if it is a choice.

 

[dave3825]

I'm gonna be pig-headed about this one and go ahead with internal charging anyway.

An online charge calculator says, assuming the cells are 80% discharged, that it would take 60 hours (that's two and a half days) at this rate to fully charge these cells.

EZ Scan software allows setting the amount of time the internal charge circuit will run (Advanced Features > Battery Options) anywhere from 1 to 98 hours, after which the charge circuit is turned-off and a "charge complete" message shows on the radio's display.

I had been allowing 16 hours of charge, and only getting about 4 hours of operation before the low battery warning sounds.

Armed with the above data, I'm going to increase the charge time to 32 hours and see if there's any improvement in run time.

Leaving a scanner charging for 16 hours, to only get 4 hours of use should be a clear message to not charge in the radio and to get a smart charger, which will charge to batts to full and yield you longer listening times.

 

[YoShep69]

Change your battery settings and the TRX-1 should last all day. Mine has for years
Check your charging time setting also.

 

[Wackyracer]

Change your battery settings and the TRX-1 should last all day. Mine has for years
Check your charging time setting also.
View attachment 142931What is you charging time recommendation?

 

[YoShep69]

14 hours, IIRC was GRE / Whistler’s recommended setting.

 

[wtp]

since i got no reply on my PM, here it is...

years ago i did not have a steady job and still bought a charger.
i live in Florida and lightning can happen at any time, also power 'blips'.
i had bought a uniden 396T for over $500, so i thought losing a $70 charger would be cheaper if 'stuff' happens.
the thing about charging in a radio is that they use time and not amount of charge to shut off.
but if the power blips it starts over again.
so my 14 hour when empty would run for much more time even up to 27 and a half hours if reset at 13.75 hours.
the few thing the batteries don't like are overcharging and heat. so an external charger is the way to go.
i am not here to sell you one, i am going to show you a discontinued model for this reason.
basically you can just put a cell in and walk away, it will do it on its own.

Powerex MH-C9000 WizardOne Charger (DISCONTINUED)​

Maha Energy is the maker of Powerex batteries, NiMH Rechargeable Batteries, aa battery charger, aaa battery charger, nimh battery charger and charging solutions. Powerex batteries offer the highest performance available today. Powerex chargers use advanced techniques for optimized battery...

mahaenergy.com
one way to have a radio run longer is to match up the cells.
so about once a month i analyze all of them and put the in order (paired up in threes)
i have 2 radios that use 3 cells each.
after about a year the true capacity of the 2500 ones can get to 1600 to 2000
under 1600 they go to the solar lights in the yard.
you can try and get that model or the updated 8 cells one.
but stay away from fast charging ones, or ones that just have a green light for 'done'.
ok i will get off the box now

 

[YoShep69]

since i got no reply on my PM, here it is..

If that is directed at me, I did not receive a PM from you. Sorry.

 

[wtp]

YoShep69, it applies to all, but was sent to and meant for N6HHR.

 

[iMONITOR]

My recommendation:

Powerex MH-C801D Charger

Powerex MH-C801D Charger

Maha Energy is the maker of Powerex batteries, NiMH Rechargeable Batteries, aa battery charger, aaa battery charger, nimh battery charger and charging solutions. Powerex batteries offer the highest performance available today. Powerex chargers use advanced techniques for optimized battery...

mahaenergy.com

You can charge your batteries and a back-up set at the same time!

 

[Wackyracer]

My recommendation:

Powerex MH-C801D Charger

Powerex MH-C801D Charger

Maha Energy is the maker of Powerex batteries, NiMH Rechargeable Batteries, aa battery charger, aaa battery charger, nimh battery charger and charging solutions. Powerex batteries offer the highest performance available today. Powerex chargers use advanced techniques for optimized battery...

mahaenergy.com

View attachment 143031
You can charge your batteries and a back-up set at the same time!

I use one of these , charges in 20min. I also use a Lacrosse BC-900. I don't think either of these are made anymore, but you may find new ones on ebay.

 

[eryoung2k]

since i got no reply on my PM, here it is...

years ago i did not have a steady job and still bought a charger.
i live in Florida and lightning can happen at any time, also power 'blips'.
i had bought a uniden 396T for over $500, so i thought losing a $70 charger would be cheaper if 'stuff' happens.
the thing about charging in a radio is that they use time and not amount of charge to shut off.
but if the power blips it starts over again.
so my 14 hour when empty would run for much more time even up to 27 and a half hours if reset at 13.75 hours.
the few thing the batteries don't like are overcharging and heat. so an external charger is the way to go.
i am not here to sell you one, i am going to show you a discontinued model for this reason.
basically you can just put a cell in and walk away, it will do it on its own.

Powerex MH-C9000 WizardOne Charger (DISCONTINUED)​

Maha Energy is the maker of Powerex batteries, NiMH Rechargeable Batteries, aa battery charger, aaa battery charger, nimh battery charger and charging solutions. Powerex batteries offer the highest performance available today. Powerex chargers use advanced techniques for optimized battery...

mahaenergy.com
one way to have a radio run longer is to match up the cells.
so about once a month i analyze all of them and put the in order (paired up in threes)
i have 2 radios that use 3 cells each.
after about a year the true capacity of the 2500 ones can get to 1600 to 2000
under 1600 they go to the solar lights in the yard.
you can try and get that model or the updated 8 cells one.
but stay away from fast charging ones, or ones that just have a green light for 'done'.
ok i will get off the box now

I got this one about a week ago (free shipping to!), it is fantastic, Very well built!!! Charge a set while i'm using the other. I find Duracell aa 2500ma batteries to be closest to there stated ma rating.

Powerex MH-C9000PRO Professional Charger-Analyzer

Maha Energy is the maker of Powerex batteries, Charger Analyzer, rechargeable batteries aa, rechargeable aa batteries and charging solutions. Powerex batteries offer the highest performance available today. Powerex chargers use advanced techniques for optimized battery charging and to optimize...

mahaenergy.com