Partial charge

[Scubafoon]

Hi,

I would like to know if the batteries in the sola lights allow for partial charging between dives? Eg. Putting it to use before it is fully charged, will it hurt the batteries or shorten the expected life of the batteries? Thanks.

 

[Diver0001]

I'm not familiar with the light in question but battery packs with Lithium Ion or Nickel Metal-hydride batteries don't suffer the same "memory" effect as the older nickel cadmium batteries do, which means they're not likely to be damaged or build up a memory when they're charged without being fully cycled. They should be charged with a charger that has a trickle mode though, so they're not subjected to extended periods of over charging, which I believe can damage them.

R..

 

[lightandmotion]

Hi Scubafoon,
I can confirm that partial charges will not shorten the overall life expectancy of a lithium ion battery like those found in Sola. With lithium ion batteries, a full charge cycle is a full discharge and charge; so if you discharge it to 50%, recharge to 100%, then discharge to 50% and recharge again, that is considered one full charge cycle since you have cumulatively discharged and charged 100% of your battery's capacity.

Diver0001 is correct; leaving lithium ion batteries permanently on charge is not good for them; neither is storing them without charging, especially at a low charge state. The best way to store Sola is in a 50-100% charged state, and top it off every 8-12 weeks or so.

 

[wve]

But for those of us who can't remember to top them off between dive trips, don't they have a protective mechanism built in that prevents them from fully draining the charge?

 

[lightandmotion]

The light can partially shut down into a sort of hibernation when drained all the way down to zero and left without charging. However, no matter what, the battery will lose some charge due to self-discharge, so if you leave it un-charged after using the light down to zero capacity, you will very likely kill your battery.

The best thing to do to prevent this is to never let the light sit without a charge for more than a few days; i.e. charge your light within a day or so after you've drained it to zero. When storing, it's good to occasionally top it off; every 8-12 weeks is the safest, though a fully charged light will usually go for longer than that and be fine.