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[Articles Home]  [Add Article]  

Recharging HT Batteries

Michael S. Higgins (K6AER) on November 2, 2005
View comments about this article!


Many hams often wonder why their batteries last only a few years awhile other hams are using their rechargeable batteries 6 years after buying their HT with long use cycles. Your charging and discharge habits have more to do with your battery life cycles.

These tips will optimize performance and obtain longer life cycles from your rechargeable batteries.

  1. Initialize your new battery by charging overnight before using it.

Nickel Cadmium or Nickel Metal Hydride: 14-16 hours

Lithium Ion: 1 to 2 additional hours after charger light turns green

  1. New, non-initialized batteries must be stored in well ventilated, cool and dry locations. Batteries stored in these conditions may be stored:

Nickel Cadmium - up to 2 years

Nickel Metal Hydride - up to 18 months

Lithium Ion/Polymer - up to 18 months

  1. If used batteries are removed from service for periods longer than 30 days, they should be discharged to about 50% of their capacity before storage.

  2. Batteries which have been stored for more than two months should be fully discharged and recharged.

  3. Do not leave your radio and fully-charged battery in the charger when not charging. Continuous charging will shorten battery life.

  4. Only charge a battery when it needs it. If it is not fully discharged, do not recharge it. Carry a spare.

  5. Stabilize batteries to room temperature (72 F) before charging.

  6. Do not return fully charged non-impres batteries to the charger for an “extra boost”. Repeated short cycle charging will shorten battery life.

  7. Batteries will no store indefinitely. Do not buy a spare battery to use in a few years after your present one dies. The battery will last longer with careful use than sitting on the shelf indefinitely waiting for initial use. Buy your replacement battery when you need it.

  8. Store batteries at room temperature. Batteries exposed to low or freezing temperatures will have a shortened life.

  9. Do not quick charge batteries from a high current source. It will separate the internal acid gell and you risk explosion from heat build up.

  10. Not all batteries packs are built the same or have the same quality. Buy cheep and buy often is the caveat in the two way radio world.

Member Comments:
This article has expired. No more comments may be added.
 
Recharging HT Batteries  
by WY3X on November 2, 2005 Mail this to a friend!
QUOTE: Batteries will no store indefinitely. Do not buy a spare battery to use in a few years after your present one dies.

I once knew someone who bought two digital watches so he could begin wearing the second one when the first one went dead. :-)
-KR4WM
 
RE: Recharging HT Batteries  
by K8MHZ on November 2, 2005 Mail this to a friend!
I once knew someone who bought two digital watches so he could begin wearing the second one when the first one went dead. :-)
-KR4WM

So much for 'hands on' experience!
 
RE: Recharging HT Batteries  
by K8MHZ on November 2, 2005 Mail this to a friend!
Mike,

Do you know any tricks to bring a sealed lead acid battery back from the dead? I have one that I suspect has one bad cell and as a result has a very high internal resistance. I really don't want to cut it apart or anything that drastic. It is a 17 aH battery so it's worth is about 20 bucks.

I have two identical ones, both the same age and one gave up the ghost.

Should I just give it a decent burial or do you have some tricks up your sleeve?

73 my friend,

Mark K8MHZ
 
RE: Recharging HT Batteries  
by KB7LYM on November 2, 2005 Mail this to a friend!
I knew a man who had no watch.So he did not know what time it was. Then he bought 2 Watches. Now he is not sure what time it is :)
 
RE: Recharging HT Batteries  
by K6AER on November 2, 2005 Mail this to a friend!
Once a sealed lead acid battery fails to hold a charge or a cell becomes dead it is best to dispose of the battery properly or as some have mentioned, “give it a decent burial”. Most cells become shorted due to impurities from the plates settling at the bottom of the cell and causing a short. Even if you could burn them away with high charging you will have damaged the rest of the cells with high current and it is just a matter of time before another cell becomes shorted.
 
Recharging HT Batteries  
by AI2IA on November 2, 2005 Mail this to a friend!
Get the most out of your HT batteries by taking full advantage of your HTs options. Follow good practice by using minimum power to transmit, and activate the auto-power off feature of your HT. Some HTs let you disable a front end stage to save power, too! Your batteries best friend is your user's manual.
 
Recharging HT Batteries  
by KC8VWM on November 2, 2005 Mail this to a friend!
A man goes to a jewelry store looking to buy a watch.
He then looks at a watch called the "Ross Perot Watch" and notices that it isn't running - the sales clerk tells him "it runs, it doesn't run, it runs, it doesn't run . . ."
 
Recharging HT Batteries  
by KE5EOT on November 3, 2005 Mail this to a friend!
Find a hobby shop that specializes in radio controlled cars. They have some pretty sophisticated battery chargers that will cycle batteries and increase their lifespan. Usually, the people in the store will cycle your battery pack for a couple of dollars.
 
RE: Recharging HT Batteries  
by K5LXP on November 3, 2005 Mail this to a friend!
K8MHZ wrote:
> Do you know any tricks to bring a sealed lead acid
> battery back from the dead?


K6AER replied:
> Most cells become shorted due to impurities from
> the plates settling at the bottom of the cell

That can be true for wet cell batteries, but gel cells don't do this. Their most common failure mode is either sulphation from sitting too long in a discharged state, or from a loss of electrolyte due to overcharging.

Gel cells (like any other lead acid battery) don't live forever, no matter how well they are cared for. Five years is about the useful limit. If you have a sealed battery that won't immediately take a charge, it's guaranteed that it's damaged, even if you do recover it. Here's how you try:

Use a lab supply with current limiting. Set the voltage to 20V or so, and the current limit to about C/20 (1/20th of the battery's Ah rating- 350mA for a 7Ah gel). Connect it to the dead battery and leave it for at least a day. It may start out drawing no current at all, but over time it should slowly rise until it hits the current limit. If after a day it's not drawing current, it's toast. If after a day of 'soaking' the terminal voltage on the battery is above 14V you can try a discharge test on it and see how many Ah the battery is capable of. Using the same C/20 rate you use for charging is a good baseline. I usually give them two chances, the initial recovery cycle, then one more after a test discharge cycle. If the Ah capacity increases on the 2nd cycle, repeat the process until you don't see an increase in Ah. The only time this drastic recovery process works successfully is on relatively new batteries that were accidentally left connected to a load for an extended period. 'Hamfest special' gels that have seen service in UPS's for a few years then left in someone's garage for another few years won't come back no matter what you do. Always look at the date codes, if they're at 5 years or more, walk away. Even if they 'test good' their cycle life is diminished and it won't take many charge-discharge cycles for these batteries to give up. In practice I've found if a battery can deliver 80% of it's rated Ah, it's worth keeping. Between 50 and 80% their life remaining is just a few more cycles, less than 50%, the game is over.

Mark K5LXP
Albuquerque, NM
 
RE: Recharging HT Batteries  
by WA4DOU on November 3, 2005 Mail this to a friend!
Making a fetish out of trying to lengthen the life of batteries is largely a waste of time. Bringing them back to life after failure is a total waste of time. In commercial applications, used daily, nicads and NiMH batteries are good for 1-2 years, especially with rapid charging. In occasional service they may be good for 4 years. If you get this kind of life or greater, feel fortunate. The above info is good practice.
 
RE: Recharging HT Batteries  
by W6TH on November 3, 2005 Mail this to a friend!
.
I once knew someone who bought two digital watches so he could begin wearing the second one when the first one went dead. :-)
-KR4WM
-------------------------------------------------

That is what I do as it is cheaper to buy a second watch at Wal-Mart than to buy a battery from Radio Shack.

W6TH.
.:
 
RE: Recharging HT Batteries  
by KC8VWM on November 3, 2005 Mail this to a friend!
Making a fetish out of trying to lengthen the life of batteries is largely a waste of time.
-----

I use to obsess over batteries trying to preserve thier useful service life, always being careful to discharge them correctly before recharging them etc. etc.

However, I have later come to realize that I have way too many devices that use rechargable batteries and little time to devote to this idea. In fact, a person could make a full time hobby out of conditioning rechargable batteries for every device they own. I have decided that life is way too short for such obsessive trivial nonsense.

So the bottom line is, when my batteries no longer work right, I get on Ebay and order replacement batteries. It ends up costing me less of my time in the long run.

73 Charles - KC8VWM
 
RE: Recharging HT Batteries  
by WB2WIK on November 3, 2005 Mail this to a friend!
>RE: Recharging HT Batteries Reply
by W6TH on November 3, 2005 Mail this to a friend!
That is what I do as it is cheaper to buy a second watch at Wal-Mart than to buy a battery from Radio Shack.

W6TH.<

::Except I won't buy anything at Wal-Mart. But I did once buy a watch from a guy selling them on the street. It was late and night, and a bad neighborhood. He said, "I know you need a watch, so you better buy this watch." I asked him how he knew I needed a watch and he said, "Because if you had a watch, you'd know this is no time to be in this here neighborhood." I bought the watch and was very happy with it.

::Nice article, Mike. I agree trying to push batteries beyond their useful life is silly. The "seven year" car batteries never last seven years. I replace car batteries every four years at most because that's how long they actually last. A little less than that if the weather's really hot. Heat kills all kinds of batteries. Keeping your HT or cellphone in the car with the windows closed during the summer is a good way to keep the battery companies in business with extra sales.

WB2WIK/6

 
RE: Recharging HT Batteries  
by KG6WLS on November 3, 2005 Mail this to a friend!
WB2WIK said:
==He said, "I know you need a watch, so you better buy this watch." I asked him how he knew I needed a watch and he said, "Because if you had a watch, you'd know this is no time to be in this here neighborhood." I bought the watch and was very happy with it.==

Well gee, Steve. Now we all know what makes you TICK. HI! You listened to way to many Cheech y Chong records back in the seventies. Even I remember that one...I think? :)

Mike

 
RE: Recharging HT Batteries  
by KG6WLS on November 3, 2005 Mail this to a friend!
Here's another one (since we're on the battery subject). Same album if I recall. Cheech's battery was dead on his cruiser and asked for a push. Reply was "Push the car? Man, get yo' mama to push the car"!
 
Recharging HT Batteries  
by K6LCS on November 3, 2005 Mail this to a friend!
Good basic information. I use the book, "Batteries in a Portable World" as the source for data on portable power. See several chapters of it onlint at...

http://www.cadex.com

Clint Bradford, K6LCS
 
RE: Recharging HT Batteries  
by K0BG on November 3, 2005 Mail this to a friend!
I don't agree with all of your premise, Mike.

The premise for fully discharging a battery before recharging it, is supposedly to keep the battery from getting a charge memory. This is an old wives tale that just won't go away. You even see it published in otherwise accurate documents from the battery companies themselves.

As for charging, NiCad and NiMH batteries can be left on charge indefinitely without harm if you limit the amount of float current. The same goes for Li Ion batteries. The problem starts because the various manufacturers sell to the least denominator, and do not design their chargers for float service.

All batteries, regardless of type have a definite number of charge cycles before the battery starts to fail. With NiMH for example, this is about 1,000 FULL recharges. Fully discharging them before recharging exacerbates their charge cycle life.

Alan, KØBG
www.k0bg.com
 
RE: Recharging HT Batteries  
by WB2WIK on November 3, 2005 Mail this to a friend!
>RE: Recharging HT Batteries Reply
by KG6WLS on November 3, 2005 Mail this to a friend!
Well gee, Steve. Now we all know what makes you TICK. HI! You listened to way to many Cheech y Chong records back in the seventies. Even I remember that one...I think? :)
Mike<

::No records. I went to many Cheech & Chong stage shows in the 70s, including a bunch of them right here at the Ice House...this was one of their standard routines. But one of the very best stand-up routines was Marin alone doing the, "Ain't that a peach?" joke with a glass rolled up inside a table napkin. They can't do that one on a record, because it's all visual. If you haven't seen that one, it brings the house down -- or did, 30 years ago...

WB2WIK/6

 
RE: Recharging HT Batteries  
by W4IKR on November 3, 2005 Mail this to a friend!
Experience only, no theories, no recommendations.

Had a Radio Shack scanner with 6 ni-cad AA's. I ALWAYS let the batteries run all the way down before charging. Those 6 batteries lasted 10 years. Gods honest truth!
 
Recharging HT Batteries  
by WF7A on November 3, 2005 Mail this to a friend!
When you do dispose of your spent or damaged wet/gel cell and rechargeable batteries, PLEASE don't toss them in the trash or into a landfill: take them to a recycling station or battery store where they can be properly disposed of.

Be kind to your ground. :D
 
Recharging HT Batteries  
by KE5EOT on November 3, 2005 Mail this to a friend!
A good battery charger is always a wise investment. Here, again, a trip to your local Radio Controlled Car hobby shop is worthwhile. The chargers that come with most HT's (and other battery devices) are unregulated chargers. They have some current limiting, but no test is done on the condition of the battery before charging starts. No test is done during or after charging either. A good charger will "peak detect" and stop charging (or go to a very slow trickle charge) until you tell it to start charging again. It should also have a current adjust capability. Smaller batteries should be charged at a slower rate. The better of these chargers will also work on either 12volts or 110. The price is usually between $50 and $100. Not a bad price to know that your batteries are ready to go when you are.
 
RE: Recharging HT Batteries  
by W6TH on November 3, 2005 Mail this to a friend!
.
Have you seen the new type of flash lights that you shake to charge the batteries. Well, wouldn't this go great in your hand held radios?

Check it out.
W6TH
.:
 
To Vito's suggestion  
by K0BG on November 3, 2005 Mail this to a friend!
I can see it now Vito, the shaking part is three times as big as the handheld it powers. And just think what your amateurs friends will sound like as they shake the heck out of it while they're transmitting.

Alan, KØBG
www.k0bg.com
 
RE: batteries  
by N0TONE on November 3, 2005 Mail this to a friend!
I have a handheld radio to be used for emergencies. I've experienced only two emergencies in five years. How the heck do I maintain those batteries, when I'm never going to discharge them?

AM
 
RE: batteries  
by KE5EOT on November 3, 2005 Mail this to a friend!
Your best bet is to use what's called a "7-11 pack". Basically, a dry cell pack with readily available batteries. There are even some batteries with an extremely long shelf life that are activated when you remove a tab and expose them to air. The great thing about dry cells is that they are everywhere and they are cheap. If your radio can't be used with dry cells, you might consider building a charger that uses dry cells to charge the NiCads.
 
RE: batteries  
by AA4PB on November 3, 2005 Mail this to a friend!
K5LXP has the right idea. SLA batteries left sitting around (i.e. not on a float charge) will sulfate. This causes essentially a high resistance in series with the cells so the battery will not draw current when a charging voltage is applied. Using a current limited supply as K5LXP stated is the best solution. If you don't have a current limited supply you can connect the battery to a 13.8V DC supply thru a current meter. When the current rises to about 1/10th of the AH capacity rating then move the battery over to a normal automatic charger to complete the charge. Using this manual method it is important to monitor the charge current. If you let it climb too high you can overheat and damage the battery.

I have revived a number of SLA batteries in this manner.
 
RE: Recharging HT Batteries  
by WB9YCJ on November 3, 2005 Mail this to a friend!
For individual "AA" and "AAA", I am very happy with the Maha "Cool" charger - model C401FS.
Fast or slow mode work great!

http://www.eham.net/reviews/detail/3353

73, Ken
 
RE: Recharging HT Batteries  
by ND5Y on November 3, 2005 Mail this to a friend!
http://www.batteryuniversity.com

73,
Tom
 
RE: Recharging HT Batteries  
by KC8VWM on November 4, 2005 Mail this to a friend!
http://www.batteryuniversity.com

-----

I guess i'm not a graduate from that institution.

 
RE: Recharging HT Batteries  
by KB2FCV on November 4, 2005 Mail this to a friend!
I used to use nicads, but for as much as I use the handheld I found it much more cost effective to use alkalines. Every nicad I had died - that's over $100 in batteries. I can pick up cheap AA's anywhere in be on the air instantly. When the batteries die I can go just about anywhere to buy new ones and be in the air right away. I will never own another rechargeable pack for an HT again. If I'm forced to get one with a new HT (that I can get an alkaline pack for) I won't even take the battery out of the packaging, it will go straight to ebay.
 
Recharging HT Batteries  
by AD5KL on November 5, 2005 Mail this to a friend!
Great info - with replacement packs as expensive as they are, I need to stretch every last mile out of them.

Gotta say that's the first time I've seen Cheech & Chong mentioned in a ham forum. Had a good laugh at that one. Far out man.
 
RE: Recharging HT Batteries  
by NN8Y on November 5, 2005 Mail this to a friend!
"The "seven year" car batteries never last seven years."
_____________________

Never say never, dude. I replaced one yesterday, the seven years were up, the "delco eye" still showed good. But I've got plans for next week and don't want to be stranded in the great white north, so I swapped it out.

I do agree that summer is harder on batteries (and generators) than winter. One of the car generator test profiles is "summer rain" which simulates being in city traffic in the rain. You've got the lights, rear defog, air cond/defrost, wipers, blower all running and minimal airflow through the engine compartment, things tend to overheat. Oh yeah, electric radiator cooling fans for you non-jeep-ers. Battery is being discharged, gen is overheating.
 
RE: Recharging HT Batteries  
by VE3VVF on November 6, 2005 Mail this to a friend!
I have an analog watch whose battery has died..It's exactly right twice a day. ;o)

From Reader's Digest: My grandmother misplaced her watch and I said I had one she could have and she didn't even have to wind it. Then my son said "Wind a watch????"

Generations, eh!

73 de Scott VE3VVF
 
RE: Recharging HT Batteries  
by KC8VWM on November 6, 2005 Mail this to a friend!
But I've got plans for next week and don't want to be stranded in the great white north, so I swapped it out.

-----

If you are adequately prepared, then there would be nothing better than being stranded in the great white
north.

:)

(one could say i'm ready)


73 Charles - KC8VWM
 
RE: Recharging HT Batteries  
by KC9CWB on November 8, 2005 Mail this to a friend!
My 1997 Ford F-150 has the original battery and still works good. It was manufactured in the summer of 1996, so that makes it 9 plus years old!
 
Another tip: Do not use cheap Maha chargers!  
by KF6IIU on November 10, 2005 Mail this to a friend!
The MH204 and other cheap quick chargers literally fry your batteries. If the battery gets too hot to hold comfortably, it's being damaged. It took me 8 or 12 destroyed AA NiCds to learn this. High capacity NiMhs are a little less sensitive to high heat, but not by much.

I also suspect a lot of radio-specific quick chargers overheat batteries.

And, yes, charging your cells only when they need it is the best way to prolong their life. I still have a set of NiCds that is 10 years old.
 
Recharging HT Batteries  
by W2DI on November 11, 2005 Mail this to a friend!
Thanks for the information, Mike.

My HT uses 7.2v, NiMH packs. I have two, one on the radio and one spare. When one on the radio exhausts, I use the spare, recharge the exhausted one and keep it available as the spare. So I do alternate the two packs.

I notice that when I recharge a pack, the terminal voltage is about 8.3V. But, by the time I need to use it, the terminal voltage is down around 7.8V. I know that NiMH cells tend to 'self discharge' with time somewhat faster than other types.

If I understand your recommendations correctly, rather than 'topping off' the back-up cell, I should use it at the 7.8V level and run it down normally?

Thanks again Mike and all. Batteries are a very interesting topic to me.

Joe,
W2DI
 
RE: Recharging HT Batteries  
by WA2JJH on November 14, 2005 Mail this to a friend!
TNX FER INFO. I thought Radio Shack had ALL the answers
to batteries(:!
 
RE: Recharging HT Batteries  
by KT4XF on November 14, 2005 Mail this to a friend!
Which is more accurate? A watch that doesn't work OR one that gaines 1 second every 24 hrs???
 
RE: Recharging HT Batteries  
by KT4XF on November 14, 2005 Mail this to a friend!
Which is more accurate? A watch that doesn't work OR one that gaines 1 second every 24 hrs???
 
RE: Recharging HT Batteries  
by KT4XF on November 14, 2005 Mail this to a friend!
Which is more accurate? A watch that doesn't work OR one that gains 1 second every 24 hrs???
 
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