7 replies to this topic

[Dive_Girl]

I collected the following info on cycling a NiMH light battery and haven't had time to try it on one of my canister batteries that started burning out quickly. I replaced it figuring the battery was cooked, but then found out maybe not so! I am curious if others have read about this and tried it themselves.

Many canister lights come standard with NiMH batteries, which are extremely durable and forgiving of mistreatment. However, they do need some TLC, such as cycling and monthly use. Find out how to prepare your canister light for its first dive.

First, you have to fully charge the battery. Assemble your light and then place the light head in a bucket or sink of water. Allow the light head to completely discharge, this means until it goes out. The light needs to be turned off shortly after it goes out. Do not discharge the battery overnight when it will be hours until you notice it that it has run down. Once your light goes out, turn the light off. Charge the battery and repeat the same discharge cycle. How many cycles your battery needs is up to individual difference in the battery. It should need between 3-5 cycles. As long as the burn time keeps going up, keep cycling!

In order to keep your battery in good condition go diving and charge your battery regularly. If you’re can’t get in at least one dive a month put the battery on a charger at least once a month. This will keep your battery conditioned and ready for when you can back into the water.

NiMH batteries are very forgiving to being mistreated. If you later leave your battery on a shelf for an extended period of time or the burn time begins to shorten. Cycle the battery again and 9 of 10 times this will return the battery to its rated burn time.

[DandyDon]

I use mostly AA NiMH batteries from Thomas Distributing and a charger from them that will drain the batteries, then automatically recharge. I just start the cycle and come back the next day. I try to run that cycle every month on the lot.

Back when most cell phones were power by NiMH, this one was one my focuses with customer enlightenment. They're more forgiving than NiCds, but cycling helps a lot.

thanks for bring this up...!

[shadragon]

I have 48 AA NiMH 2600 MaH batteries I use in flashlights, strobes, cameras, etc. I drain them 4 at a time in one of those closet tap light thingies, then recharge them. I try to do that at least once a month and the whole process takes 4-5 days. Helps keep them at their full potential. They say NiMH's will last 1000 charges if used properly.

[DandyDon]

I have 48 AA NiMH 2600 MaH batteries I use in flashlights, strobes, cameras, etc. I drain them 4 at a time in one of those closet tap light thingies, then recharge them. I try to do that at least once a month and the whole process takes 4-5 days. Helps keep them at their full potential. They say NiMH's will last 1000 charges if used properly.

You might find one of these a lot eaiser....

$15 from Thomas Distributing. I'm told that battery life can have a lot to do with quality of charger, and that they sell the best. But then I really don't know how to tell?

[Brinybay]

What kind of NiMH batteries are we talking about? C and D cells, or is it some kind of proprietary battery with it's own proprietary charger? And is this only in reference to HID's? (Until they make a much cheaper, much more durable bulb for HID's, I won't buy one).

I use NiMH C cells in my UK LED C8. I haven't had any problems with them burning out quickly. The only drawback is you lose a little oomph because they're 1.2 volts as compared to 1.5 volts for the disposables.

[Dive_Girl]

What kind of NiMH batteries are we talking about? C and D cells, or is it some kind of proprietary battery with it's own proprietary charger? And is this only in reference to HID's? (Until they make a much cheaper, much more durable bulb for HID's, I won't buy one).

I use NiMH C cells in my UK LED C8. I haven't had any problems with them burning out quickly. The only drawback is you lose a little oomph because they're 1.2 volts as compared to 1.5 volts for the disposables.

I am talking about my cannister light battery. It has its own charger. You know, maybe I can't cycle it. The light is an HID. Any thoughts on this? I haven't started this process as I noted above I am info collection mode and wanted comments from others.

Also, (obstaining from sophmoric laughter here ), what is a deep discharge? I recently came across this warning:

Warning -- Deep discharge destroys your battery!

Completely discharging a gel cell or NiMH battery utterly destroys the battery -- even if the battery is new. Discharging the battery below 10.5 volts (a condition known as "deep discharge") seriously damages the battery and is nearly as bad as completely discharging the battery. The HID light is capable of drawing battery packs well below 10.5 volts without any noticeable decrease in light output or change in light color. At about 7.5 volts, the HID light abruptly goes completely out -- long after permanent damage has been done to the battery. Because the HID bulb gives no warning of low-battery voltage level, it is important that you keep light use well within recommended "burn" times.

...my brain hurts...

[running_diver]

Warning -- Deep discharge destroys your battery!

Completely discharging a gel cell or NiMH battery utterly destroys the battery -- even if the battery is new. Discharging the battery below 10.5 volts (a condition known as "deep discharge") seriously damages the battery and is nearly as bad as completely discharging the battery. The HID light is capable of drawing battery packs well below 10.5 volts without any noticeable decrease in light output or change in light color. At about 7.5 volts, the HID light abruptly goes completely out -- long after permanent damage has been done to the battery. Because the HID bulb gives no warning of low-battery voltage level, it is important that you keep light use well within recommended "burn" times.

...my brain hurts...

The short answer is that says leaving your HID light on until it goes out or even comes close to going out will destroy the battery.

Assuming the statement above is true, then you will need a special charger to cycling your batteries.

The slightly longer answer is that as you use a battery, the voltage slowly drops. Fully charged, your battery probably provides around 12V. As you use it, the voltage output will drop. This is why the light dims. How fast the voltage drops depends on the type of battery and the type of light. The statement above says that if you continue to use your light after the battery is only producing 10.5v, then the battery will be damaged and likely need to be replaced. Furthermore it goes on to say that your light will gladly continue to function until the voltage is well below 10.5V. Which means you can't use your light to discharge your battery without risking your battery.

I don't know if the statement is true, but you need to consider who is saying it. If it's coming from someone that makes special chargers, then it should be considered suspect. If it comes from your battery manufacturer, then you should probably listen.

Ross

[ScubaDadMiami]

You can use a burn tester, which will discharge your batteries while testing them.