Battery life

I was thinking about buying 2 used video lights by light and motion, they have sealed batteries and have not been used for 2 years. Owner had charged them and they seemed OK, but the replacement covst for batteries made it appear a bit of a risky purchase, so decided against.

Any thoughts on buying lights with used batteries?

Hmmm, a bit of a gamble maybe. 

I'm not sure what the deal is on changing L&M batteries if that need should arise but probably have to return them to the dealer or manufacturer. They aren't user serviceable to the best of my knowledge.

If feasible you could ask a potential seller to run the lights in a tank of water and ask them to tell you how long they last. Other than that, if you're buying them from a WP member through the Classifieds, check out their history: how long have the been a member and contributed etc..... at least then you might have an idea of their honesty.

Buying used lights isn't something to rule out but a measure of caution.....

There is certainly a risk and it goes up with the age of the lights.  Batteries of course have  a limited life and will eventually fail.  I would suggest allowing for battery failure in any purchase decision.   The older the batteries are and the more use they have had the less you pay for the lights.   Letting batteries sit idle for long periods is also of course potentially bad for long term life.  This would mean that lights that use AA NiMH or standard rechargeables like 18650 Li batteries can command higher prices as the replacement battery cost is less.

Just don't even consider buying an UW light that does not have a user replaceable battery. If you intend to use it for a few years, the cells will need to be changed. Buying used just accelerates that timeline. Stick with products designed to be usable for many years.

Thanks for the input, I am definitely leaning towards user replaceable.

the replies made me think, “How would I feel if other kit that I own had non-user replaceable batteries?” Not a great concept, mass market batteries are expensive enough without making it worse.

Another thing about sealed batteries - consider the use case of making multiple dives off a small day boat that does not have onboard electricity supply. With removable batteries, you can easily bring spares and swap between dives, but with a sealed battery, you're stuck hoping that the charge will last you through the day.

As per TimG suggestion - ask him to test how long do they last in water from fully charged to 0, so you can compare against the official specs. Important thing is to ask him if he has charged them regularly, even when not used (more about it below), or left them uncharged for the whole 2 years. As all folks are saying here - proprietary battery packs are not the best solution. Apart from a rip off (those are two batteries that you can get for 5-10 Euro, and i am talking Sanyo etc not chinese crap, put together, then sold, at least in EU for a whooping price of almost 80 Euro), if that thing dies on a trip, that's it, no way you can get one in the middle of Indonesia. Also Solas use proprietary charger (another garbage to carry). They now offer USB-C adapter but at another whooping 50 Euro+.

Personally i would stay away from L&M products - they are nice when they work but batteries and most importantly PCBs are of very poor quality. And the moment warranty ends they will charge you almost price of a new light if anything else than batteries need fixing (though if you ask them to fix batteries its gonna cost you ). They seem to have a lovely business model where servicing cost and arm and a leg. You can find a few topics on Scubaboard of folks complaining about those lights and PCB quality, as well of one where they put DYI battery together and somebody found a possible non-Sola replacement (Hope it is ok to link):

https://scubaboard.com/community/threads/battery-replacement-for-sola-1200.522330/page-3

As for the "why is it important to charge Solas regularly" - they have crappy PCB that die. And those you cannot buy. And they refuse to send them out, instead demanding a whooping 200 Euro+shipping for a replacement service. My story below, as went through a few with my gf over the years. From memory:

Sola 800 - not charged for a few months, died, 100+ Euro to fix (was a long time ago, when prices were lower, PCB/Battery dead

Sola 800 (the same) , not charged for a few months, PCB dead again.

Sola 1200 - not charged for a few months, PCB has issues, all works but light will not stay on, LM refuses to send 5 USD Chinese made PCB and demands 200 Euro for a replacement and shipping a light to them (because it is so hard to replace...)

Sola 1200 (another) - PCB issues, when charging/using only green/red battery status is visible , orange no longer shows. Guess will die soon.

The only Solas that i have and still work are the Nightsea ones...but i suspect this is due to the fact these were barely used, as while i might do 40 dives a trip, every single one with normal Sola, Nightsea only does 1-2 max.

No more Solas for me, Inon and AA all the way now

4 hours ago, makar0n said:

As for the "why is it important to charge Solas regularly"

I'm with makar0n on this. I've bought a Sola P800 years ago and failed to charge it for a few months. It was the devil's own job to get it to wake up again and recharge. I now have an alert in my calendar to charge it regularly on the first of the month.

One more hit against the L&M Sola - the charging ports on the light and the prongs on the charger are very prone to corrosion. You need to do constant work to clean these things and apply contact cleaner to even be able to charge these things. I've used sandpaper to clean these for other divers many times on trips. Another time a friend forgot the proprietary charge and I helped her jury-rig a connection to a standard charger using a couple of paper clips, a cork, and a rubber band.

I had the Sola 1200 from when it was first released, and I really liked the lights size, controls, and function. I even changed the battery myself (see link above) and kept it going another year or two. I eventually dropped it and broke the (plastic) case, but I'd already moved on to better options with replaceable batteries.

Today I use a Kraken 2800. Replaceable battery. Aluminum case.

2 hours ago, davehicks said:

One more hit against the L&M Sola - the charging ports on the light and the prongs on the charger are very prone to corrosion. You need to do constant work to clean these things and apply contact cleaner to even be able to charge these things. I've used sandpaper to clean these for other divers many times on trips. Another time a friend forgot the proprietary charge and I helped her jury-rig a connection to a standard charger using a couple of paper clips, a cork, and a rubber band.

I had the Sola 1200 from when it was first released, and I really liked the lights size, controls, and function. I even changed they battery myself (see link above) and get it going another year or two. I eventually dropped it and broke the (plastic) case, but I'd already moved on to better options with replaceable batteries.

Today I use a Kraken 2800. Replaceable battery. Aluminum case.

Ha you are the battery wizard...dumb me not connecting the names ...if only one could also find some Aliexpress PCB source as well.

Another valid point indeed - they will corrode like hell, charger will too, since inevitably you will end up charging after the dive and those plug holes always keep some water (q-tip helps with that a bit)

4 hours ago, davehicks said:

You need to do constant work to clean these things and apply contact cleaner to even be able to charge these things

Snap. Been there, done that!

Thanks very much to all for sharing experiences and advice, very much appreciated.

I ended up taking the advice of an old dive buddy who works for a respected dive business and have bought an Anchor video light with replaceable batteries. The two main deciders were the fact that I have dived with the guy and trust him 100% and that Anchor get good reviews for customer service.

an upcoming 3 week trip to Sharm will be the proof of the pudding.

Thanks again.