2024: view for primary/backup torches, and dive knife

[dylanfromwinnipeg]

Why would rechargeable batteries be bad for backup lights. I’d love to be able to recharge my backup lights between each dive. I’m always afraid that one of my backup lights has accidentally turned on and drained the battery, but there’s just enough juice left in it to look like it’s working when I test it. If I could fully charge them before every dive I’d feel way more comfortable.

 

[crofrog]

Why would rechargeable batteries be bad for backup lights. I’d love to be able to recharge my backup lights between each dive. I’m always afraid that one of my backup lights has accidentally turned on and drained the battery, but there’s just enough juice left in it to look like it’s working when I test it. If I could fully charge them before every dive I’d feel way more comfortable.

because they have self-discharge, and are more likely to experience a sudden failures. Alkaline batteries are very stable and reliable, and constantly recharging backup lights would increase the risk of one of them flooding by the opening and closing, and it's just 1 more thing to have to deal with. It's nice just to be able to throw the backup lights onto your harness and not worry about them. Twist on lights are preferable because they're unlikely to turn on accidentally and do not have a switch to fail.

 

[lostsheep]

(Li ion) are more likely to experience a sudden failure…

Do you have anything to back this up? That might have been the case years ago but I’m highly skeptical it still is.

constantly recharging backup lights would increase the risk of one of them flooding by the opening and closing,

Any type of diving that requires backup lights requires oring inspection and maintenance , this is a non issue if you carry spares and are paying attention. Further, many new lights don’t require opening to recharge.

The increased energy density, lifespan, and end-of-life recyclability of modern lithium ion batteries should have people rethinking the use of alkaline batteries.

 

[crofrog]

Do you have anything to back this up? That might have been the case years ago but I’m highly skeptical it still is.

Just a logical fault tree style analysis. There are more failure points and ways for it to fail vs an alkaline battery. Lithium-ion include more complex internal structures (including a Battery Management System) and involve a charging cycle that increases the risk of internal failures, such as overheating or short circuits. It's easy to damage a battery when charging it and not be aware of the impact to run time and overall battery health. Obviously these failures don't exist with alkaline batteries.

Any type of diving that requires backup lights requires oring inspection and maintenance , this is a non issue if you carry spares and are paying attention. Further, many new lights don’t require opening to recharge.

Each time you open the light to charge the batteries is a higher chance it's going to flood the next time you use it...

 

[flymolo]

Do you have anything to back this up? That might have been the case years ago but I’m highly skeptical it still is.

they said it was a lithium battery that likely caused the fire on the conception, for one

also if you have a scooter or can light i'm sure you've seen the warnings not to charge them unattended, not to charge them too hot, not to charge them too cold, not to store them in very hot cold temps, etc. that sort of thing isn't an issue with plain alkaline batteries

 

[NothingClever]

It doesn’t make me feel any less of a diver to run alkaline powered back ups port and starboard. While there are definitely some advantages to lithium batteries and there’s low risk of a catastrophic outcome with failure in an OW environment, I’m not sure I want any room for doubt about my alternate and contingency lights when 2000m back in a cave.

ETA: To be clear and to head off any accusations of “stolen valor” so to speak, I’m not cave qualified but that’s the direction I’m headed. The confidence behind my above position is derived from years of experience in other types of high risk operating conditions.

 

[flymolo]

Charging backup lights is just a thing I don’t want to think about considering I mostly don’t even bother to remove them from my harness straps

 

[lostsheep]

they said it was a lithium battery that likely caused the fire on the conception, for one

also if you have a scooter or can light i'm sure you've seen the warnings not to charge them unattended, not to charge them too hot, not to charge them too cold, not to store them in very hot cold temps, etc. that sort of thing isn't an issue with plain alkaline batteries

None of that has anything to do with their efficacy in a back up light.

WRT the conception , that one hits closer to home for some of us…and no one knows if it was a li ion or an overloaded circuit last I checked.

 

[flymolo]

None of that has anything to do with their efficacy in a back up light.

WRT the conception , that one hits closer to home for some of us…and no one knows if it was a li ion or an overloaded circuit last I checked.

that's not what the reports concluded

 

[lostsheep]

Charging backup lights is just a thing I don’t want to think about considering I mostly don’t even bother to remove them from my harness straps

That is legit , but I still maintain it’s just not a big deal to keep them topped up.

that's not what the reports concluded

Last I heard they knew the area of the ship that the fire originated but not the source. If you’ve ever been on those boats you know how scary that **** was