05-31-2000, 09:59 AM #1Fireman488Firehouse.com Guest
Rotating portable radio batteries??
Currently our department keeps all portable radios in chargers, on trickle charge, on all of our rigs.
It has come to our attention that this procedure is seriously damaging the lives of the batteries.
Any ideas on how to set up a rotation program to ensure fully charged radios without compromising the life of the batteries.
05-31-2000, 11:08 AM #2bob1350Firehouse.com Guest
Our dept has gone to the 800 radios. All officers were given two batteries. We were told never have a radio in the charger while its on, leave the radio on at least 8 hours a day, swap your batteries very time the radio needs a charge. Turn off your radio when changing the battery. When the battery charger shows a green light, take it out. I get 12-15 hours out of a battery. The old VHF radio I had, I got about 6. Not knowing what brand of radios you use, or what freq. your on, its hard to give specific, but get the things out of the charger. By the way 800 radios suck!
06-01-2000, 12:23 AM #3LMRCap1Firehouse.com Guest
Don't know about a rotation system but you should also run the battaries to complete dead-Leave it on in the vehicle for 24 hours usually does the job then make sure it gets a full charge. We were instructed to do this once a month to keep the battary from building up a memory. Just don't do all your portables on the same day.
06-01-2000, 02:24 PM #4Pelican631Firehouse.com Guest
I'm guessing you're using NiCd batteries, rather than the new NiMH ones. If that is the case, the recommended handling is to let them completely discharge (die), and then fully charge them. Trickle charging NiCds 24/7 isn't a good idea. You're basically cooking them. The new NiMH and Lithium Ion batteries are different, and I'm not up on those. There isn't really a good way to keep portable radios in a truck so that they are always charged, in my opinion. That's why our department went to buying enough radios so that everyone has their own. They take care of charging. I know that won't work for everyone because of the huge expense. Thats my two cents.
06-01-2000, 07:55 PM #5PTFD21Firehouse.com Guest
Our Dept. has set up a scheduled time to drain all portable batteries completely. Every Sunday the oncoming shift turns on all portables and switches the channel to one that is not in use and leaves them on till they die then those batteries are put in the charger and the spares are put on the portables and drained and then charged. It seems to help. The next shift makes sure every battery has been rotated and puts all spare batteries in our radio bag.
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06-01-2000, 10:35 PM #6HYTHE FIRE DEPARTMENTFirehouse.com Guest
If you are using the nickle cadnium batteries, you might want to look into purchasing a battery drainer. We were looking into them a while back, but we decided that for the amount of radio's we have, and the amount of time we use them, it was cheaper to purchase new batteries every two to three years.
With the drainer, you can take the half used batteries off of your radios after a call and replace them with fully charged ones. The drainer then fully depletes the power on the half used batteries so when you charge them they do not develop a memory.
We found that leaving our radios on to drain them took to long to kill the battery. Now we have are chargers hard wired into our trucks, and leave the radios in the chargers until the next call.
06-02-2000, 07:55 AM #7munsonFirehouse.com Guest
we have one day a week were change all the batteries. on the frontline rigs they are usually changed every other day due to heavy usage.
do or do not there is no try
06-02-2000, 02:15 PM #8ResqCapt19Firehouse.com Guest
06-02-2000, 04:02 PM #9Dalmatian90Firehouse.com Guest
If an option for your radios, switch to NiMH (Nickel-Metal-Hydride) or LiON (Lithium Ion) batteries when the NiCads die. Those two aren't susceptible to "memory" like nicads. Especially with the LiONs, you will probably need a new charger for them. Both offer more battery life compared to weight than NiCads...LiON has better performance but uses different charger than NiCad or NiMH and are more expensive, but the performance is better.
03-16-2007, 01:55 AM #10
- Join Date
- Mar 2006
2 ideas i have came up with since we have the same problem is:
1) wire a spare charger for each of your radios in the cab. Leave a spare battery in there to charge fully. Leave your portables on all the time, and when you get in the cab chage the batteries out.. This may not work well if it is hard to change your batteries ie need a screwdriver.
2) have all of your portables on your regular wire (plug in) on your ac outlets in your cab. Put a timer in the circuit to only charge for a few hours a day, about 4-6. Seems to work well. Make sure to try this with one radio that is not a 1st out truck or try it on a spare radio to makesure your batteries will hold a charge like this. Ie: completely charge a radio, then leave it on for an hour or so. Turn it off, then put on the charger.Each day after, turn it on for about an hour, then off and put back on chager with the timer set for what you would have it set for on the truck. after a few days. Turn it on, scan mode and see how long it takes for it to go dead or to the point where you have trouble transmitting. This will give you a general idea on how well this will work for you.
03-16-2007, 09:43 AM #11
Wow, this is an oldie ....
Anyway, a standard NiCd battery will loose a couple of percent of capacity per day, so as they sit on the shelf they self discharge and left unattended will be dead, hence you need to keep them charged. We use to keep our portables on the chargers 24/7 (other than when being used for calls of course), and subsequently had to replace the batteries very frequently as this is very hard on them. What we have been doing for the last 4 years or so is as follows...all radio chargers are wired to an electric timer. They charge every Saturday for 12 hours. The electric timer we used has an over-ride button so if we have a call and use the batteries someone pushes the over-ride button when we get back to the station. The timer is also programmed to turn off every night @ midnight. This way if we need to charge them we just push the over-ride and they will shut off later that night. This has been working very well, I just recently tested a variety of our batteries for capacity and they were all in excellent shape and some of them were several years old. I think this method has doubled if not tripled our actual battery life-cycle. The only problem we have experiences is that if someone forgets to turn the portable off before putting it in the carger it will be dead in a day or so as the charger is not always on, but thats a user training issue that can be overcome.
One other thing to note is that just because your charger light turned green does not mean its done... Many models of charger enter a rapid rade charge cycle when the battery is inserted and once the battery reaches roughly 80% or so it switches to trickle mode and turns the light green. You often need to leave the radio in the charger for a few more hours to actually get the battery up to 100%, but this varies by manufacturer and battery type.
Lithium Ion batteris have been very good as well. Life cycle seems longer, they don't develop the memory effect, and you can get some very high capacity batteries, they are of course more expensive.
03-16-2007, 02:34 PM #12
The lithium ion batteries are very easy to damage, which few salespeople understand or will tell you. Killing a lithium ion battery completely can lead to the battery being completely unusable as there is a safety circuit inside the battery that will prevent it from being charged if the voltage gets too low, even if only once. You could do this to a brand new battery within a couple days if you don't use it properly.
Lithium ion batteries also have a short shelf life, unlike NiCad and NiMH. Don't buy extras for the future as a lithium ion will only last about two years even if stored properly and never used.
I prefer NiMH since they are the largest capacity, although heavier than the lithium ion.
From a website (I forget which)
* Unlike NiCad batteries or NiMH batteries, lithium-ion batteries should be charged early and often. However, if they are not used for a longer time, they should be brought to a charge level of around 40%. Never use the battery care functions some cellular phones provide for nickel based batteries. (This will deep cycle the batteries.)
* Li-ion batteries should be kept cool. Ideally they are stored in a refrigerator. Aging will take its toll much faster at high temperatures. Keeping them in very hot cars can kill lithium-ion batteries. Stored Li-ion batteries should be stored at 40% capacity.
* Avoid running the battery through "deep discharge" cycles — that is using it until it's fully depleted to 0 %.
* Many authors suggest that freezing Li-ion batteries may be detrimental. However, most Li-ion battery electrolytes freeze at approximately -40 °C. Household freezers rarely reach below -20°C. Published experiments demonstrate that freezing (even below -40°C) is unharmful if the battery is fully warmed to room temperature before use. More details are given in the book "Characteristics and Behavior of 1M LiPF6 1EC:1DMC Electrolyte at Low Temperatures" by L.M. Cristo, T. B. Atwater, U.S. Army Research, Fort Monmouth, NJ.
* Buy Li-ion batteries only when needed, because the aging process begins as soon as the battery is manufactured.
04-07-2007, 10:08 PM #13
- Join Date
- Feb 2004
- Bainbridge Township, Ohio, USA
Conditioning and rotation
Heres what you have to do, regardless of the frequency or type of radio you need to keep the batteries on a rotation. Nicd for sure has a very short memory. But there is hope. you need to purchase a battery conditioner and condition the batteries every 3 months, so every three months the batteries get a break. pus if they are nicd the conditioner will put new life into them. now if you batteries are NIMH then they donot have a memory but can be affected by constant charging so they need to be fully discharged recharged and left out o the charger as long as the atmosphere is like 60 degrees or higher it will hold its charge quite well and be ready for any emergency. now if your department really has the big bucks and you are using newer model motorola radios switch the the impress batteries (my department just did) they are called smart battieries they only charge when they need to be charged have no memory and a 2 year warranty. also another helpful tip. use then same brand battery as the radio. it may cost a little more but they work better. example if you use motorola radios use motorla batteries.
04-09-2007, 02:10 PM #14
- Join Date
- Mar 2004
- Memphis Tn,USA-now
When I worked on the river and had my own VHF walkie talkie to talk with the boat pilot,I'd charge the battery at home for between 8 and 11 hours,depending if I worked my second job or not.If I had a long day on the river,I always carried the charger since the boats run 110v 60 Hz electricty from the generator.Once a month I'd drain the Ni-Cad battery completely by turning the squelch off and the volume down.I'd leave the thing in my tote bag and in another room so I didn't have to listen to it hissing like a snake for two days.The night before I was to go back to work,I'd charge it up 12 hours.
This kept the battery from being recharged after a regular number of hours and developing a memory for that point and only working for that long and dying on you when you needed it the worst.
The nickel metal hydride something or other batteries,you can recharge at any level without worrying about it developing a memory.
My department issued radio with its nicad,I kept in my turnout coat pocket and recharged it every 4 or 5 calls.Since I wasn't an officer,I rarely transmitted so my battery lasted longer.We got two batteries with our two ways so we could rotate them out as needed.Keep the off duty one drained if you have a quick charge function on your charging base.That way,it won't be as apt to mess up when you do put it to work.
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