UK Light Cannon Rechargeable Batteries

[scubacalifornia]

I took my Light Cannon out for two more dives this weekend, having used it for one dive a week ago and not recharging the batteries since. It died early into my third dive. All of my dives were about an hour. So, bottom line is I can depend on it for 2 dives without a recharge. I was getting 2-3 dives from a set of Duracels. Perhaps the higher voltage rating (1.5v) of alkaline cels vs 1.2v of NiMH kept the collective voltage of the eight cels above the minimum operating range of the LC a bit longer. I'm still thrilled to be saving the money & the environment and the light performs like a champ with the rechargeables. The charger I bought also works very well.
Kevin

 

[Hoosier]

Thanks for your update. I re-checked the lighting time last weekend. As you may remember, I have 16 cells for two Canons. It runs about 2 1/2 hrs for both lights.
With Duracels, I used to get about 4 1/2 hr lighting time though.

So, how many min. did you used for two dives?

Thanks in advance,

I took my Light Cannon out for two more dives this weekend, having used it for one dive a week ago and not recharging the batteries since. It died early into my third dive. All of my dives were about an hour. So, bottom line is I can depend on it for 2 dives without a recharge. I was getting 2-3 dives from a set of Duracels. Perhaps the higher voltage rating (1.5v) of alkaline cels vs 1.2v of NiMH kept the collective voltage of the eight cels above the minimum operating range of the LC a bit longer. I'm still thrilled to be saving the money & the environment and the light performs like a champ with the rechargeables. The charger I bought also works very well.
Kevin

Thanks for your good info. Even though I used the computer controlled charger, I found out that the batter can get hot when I take out and re-put the battery in the middle of recharging process. It was only four cells in one charger. I am not sure if these 4 cells are damaged or not. It isn't supposed to be hot in the charger though....

NiCad memory issues are old news from the early technology used in satellites. It has been decades since NiCads really suffered from memory problems. While both NiCad and NiMH cells can be damaged by overcharging, NiMH batteries are more sensitive. Overcharging either at a slow rate will cause voltage depression (probably what people call "memory" problems) while overcharging them at a fast rate will destroy them. Consider getting a good quality peak-detection charger to prevent damage. If your instructions say to "stop charging when the batteries get warm" then the charger is crap and the manufacturer should do better because once they get warm, they are fully charged - more charge time will damage the cells. There are many quality chargers out there. See www.rcuniverse.com batteries forum for good info on batteries. These guys are serious about batteries. When one fails, a plane or heli will crash (if flying) or go out of control (on the ground) with potential injury, death, or property damage. <http://www.rcuniverse.com/forum/forumid_84/tt.htm>

 

[scubacalifornia]

I got about 2 hours + of run time on the NiMH. I used to get about 3 hours from Duracels. Still beats the you know what out of spending a buck a battery. There are far too many toys still to be acquired to waste scuba funds on batteries
Kevin

 

[Hoosier]

Thanks for verifying my inquires.

If then, we have almost an identical run time. I expect more than that though

I got about 2 hours + of run time on the NiMH. I used to get about 3 hours from Duracels. Still beats the you know what out of spending a buck a battery. There are far too many toys still to be acquired to waste scuba funds on batteries
Kevin

 

[bgi]

Unfortunately, NiMH's don't like getting hot. They will still work, just with less capacity.

What kind of charger did you get? Sounds like a good deal if it works well. I use the MRC 959's for all kinds of batteries and packs.

 

[TheDom]

I think Hoosier and I are shopping at the same place for batteries: Walmart, Rayovac "Heavy Duty" C-cells for $0.99 for a four-pack! I generally get 1-2 40min dives out of them, which is pitiful, but you can't beat the price! I have two LC's so when one dies, back to the dive bin it goes, and out comes the fresh one. Depending on how long the NiMh cells keep working for you, I might consider getting some of them and a charger, because the short battery life is annoying when I want to do longer dives.
-Dom

 

[Hoosier]

Yes, it will be a good back up battery pack even though you have a rechargable batteries. And, it is a darn cheap...

I think Hoosier and I are shopping at the same place for batteries: Walmart, Rayovac "Heavy Duty" C-cells for $0.99 for a four-pack! I generally get 1-2 40min dives out of them, which is pitiful, but you can't beat the price! I have two LC's so when one dies, back to the dive bin it goes, and out comes the fresh one. Depending on how long the NiMh cells keep working for you, I might consider getting some of them and a charger, because the short battery life is annoying when I want to do longer dives.
-Dom

 

[lairdb]

I think Hoosier and I are shopping at the same place for batteries: Walmart, Rayovac "Heavy Duty" C-cells for $0.99 for a four-pack! I generally get 1-2 40min dives out of them, which is pitiful, but you can't beat the price!

Tangent/rant: "Heavy duty" is an outdated term. The term originated to distinguish zinc chloride batteries from the traditional carbon zinc batteries, since they did indeed offer more capacity and a better discharge curve. Alkalines offer anywhere from 3 to 7 times the capacity of zinc chloride batteries, so the term "heavy duty" has gone from useful to misleading.

 

[Hoosier]

Ok, it sounds like tha you are an expert on the battery. If then, how can you compare those batteries' (heavy duty) life to the 5000mah rechargable batteries's one? Thanks in advance,

Tangent/rant: "Heavy duty" is an outdated term. The term originated to distinguish zinc chloride batteries from the traditional carbon zinc batteries, since they did indeed offer more capacity and a better discharge curve. Alkalines offer anywhere from 3 to 7 times the capacity of zinc chloride batteries, so the term "heavy duty" has gone from useful to misleading.

 

[lairdb]

Ok, it sounds like tha you are an expert on the battery. If then, how can you compare those batteries' (heavy duty) life to the 5000mah rechargable batteries's one? Thanks in advance,

Not an expert... but knowledgeable enough to know that the question goes far beyond the raw mAh statistic. In most applications these days, you have to consider the raw capacity in light of the discharge curve (the voltage drop as the battery capacity is consumed.)

If your device requires 1.2 volts to function, battery A, which starts at 1.5 volts but drops to 1.1 volts after only 10% of it's 2200mAh capacity is consumed, is nearly useless. Battery B, which starts at 1.37 volts and maintains 1.3 volts throughout 85% of it's identical 2200mAh capacity, is much better. This example is drawn directly from alkalines (A) vs. NiMH (B) as used in my digital camera. Both 2200 mAh batteries; I get about 3 photos out of the alkalines, and nearly a hundred out of the rechargables.

For the Light Cannon, the questions would be what voltage range the ballast finds acceptable to reliably strike and maintain the lamp, and what it's steady consumption rate is, and so forth.