Thanks for Good Advice on batteries and chargers!

[Caveeagle]

I have been using some off brand 18650 batteries in lights for OW/Cavern dives as well as small back-up lights over the last year or so. I had been reasonably happy with them for reliability and burn times. I have heard many comments about them being "junk" and not to use anything with "fire" in the name etc. But they seemed to be performing well in the short dives and with limited use in back-ups so I was not too worried about it. Add to that.. most of the criticism I have seen has been lacking of DATA or any convincing facts. (for me anyway).

So, I am here to post up some information that has me convinced that there is a major quality difference on Li-Ion batteries from more reputable sources.

Thanks to two people in particular:
@tbone1004
&
@stuartv

Who cave me some sound advice on a good set of 3400mAh 18650 batteries, and what appears to be a great charger/testor, in the XSTAR VP4

Amazon.com : Xtar DRAGON VP4 PLUS Charger with charger pouch probes adapter car charger with Xpower Battery Case : Camera & Photo

https://www.amazon.com/dp/B00WDQTIN...TF8&colid=20R1B8EYPPCRL&coliid=I115F5AJGO63FM

I am still learning my through all the features of this charger, but specifically, It allows be to test the cells I have been using, and compare them to the new cells I have on hand.

First off.. The "Ultrafire" 5000mAh cells I have are over a year old, and now showing be an average of 400mAh of power when fully charged

Another batch of 'look alike' (not even labeled Ultrafire) 5000mAh cells are about 6 months old and now show an average of 650mAh when fully charged.

A set of EVVA 3400mAh batteries came with a Dive Rite LX20 cordless primary light I recently bought. These are only a month old and test out to ~3390 mAh of power

I just got in a couple sets of EEPOWER 3400mAh so I can hopefully retire the el-cheapos from rotation in my dive lights. I have only tested out the first pack, but at >3300mAh, I am reasonably pleased with them.

Conclusion... The el-cheapo / off-branded cells might work ok for short duty use, or just around the house.. But they will not be going into any of my dive lights again.

 

[Texasguy]

Was this not well known already? Did you just learn it, or something?

 

[eelnoraa]

5000mAh just doesn't happen on 18650 yet. Possible in the future, but far from it in current Li-on technology. Even Tesla cant produce 18650 at that mAh. So more important than avoid "fire" brand is to realize what the reality is. Not that I recomand, but I did have had good experience with Ultra fire twice. I guess I was lucky

 

[Caveeagle]

Was this not well known already? Did you just learn it, or something?

Well, trying to assume your not just being a smart a** about this.. I thought I was pretty clear in that I had heard to "avoid cheap batteries" and that "xxxx-Fire" brands were all "Junk", but had not actually been presented with any DATA to back that up. Add to that, my initial experience with some of the cheap 18650s was actually pretty positive.

For Example: I purchased several Dive Rite BX-1 lights to be used both as back-ups and for my kids to use in OW & Limited Cavern Diving (ie: Ginnie & Blue Grotto). These lights come with 3xAAA batteries but also include a sleeve you can swap in to make an 18650 battery work. I already had 4 "ultrafire 18650" batteries that came with a flashlight The just got used around the house & Yard, so I did a quick swap and a visual test. Even the cheap 18650s performed significantly better than the set of AAAs. Typical dive with my kids was less than 45m, and over the course of 6 months, I never had any issues with this combination. Shoot, the BX-1 with the cheap 18650, actually out perfomed my older RX-2 Canister light for the shorter dives. And so,,, Yes, in the absence of any real DATA (that I had seen), I did somewhat question "how bad" these cheap batteries were.

And like it or not.. the diving industry is full of people who perpetuate half truths and mythology based on personal bias and ignorance. How many have heard X-Brand of Regulator is trash, or "will get you killed" by somebody with a strong bias towards some other brand of gear. This is also VERY true with dive lights. There are some very good "off brand" dive lights out there at a fraction of the cost of the big names. And plenty of people willing to browbeat you if you are not willing to pony up the premium cash for the higher priced units. ...So I had not completely dismissed the possibility that the cheaper batteries might be at least "passible" for limited use.

With the question still open in my mind... I was still willing to learn. Based on some good advice, I purchased a charger capable of testing cells and decided to post up my actual results. DATA can be a beautiful thing when used properly.

 

[Caveeagle]

Just a little more follow up...

I have now tested and charged all 8 of the new EEPPower 3400mAh batteries. All but one tested out with >than 3400mAh right out of the box, and one of them showed just under at around ~3385mAh.

Re the EVVA 3400mAh batteries that came in my LX20 Light: I was diving yesterday and over the course of two dives, I was in the cave for 92 minutes and has the LX20 on high for nearly all of that time. I put the 4 EVVA cells on the charger last night and they all took right at 900mAh charge to get back to 100%.

**I had the EEPPower cells in my back-up lights, so no usage other than surface checks..

Conclusion: The el-cheapo batteries could not have had the power to last for both dives at 92 minutes and certainly would not have given me any reserve time to deal with any issues.

They would have 'probably' done 'good enough' in the back-up lights, for either of yesterdays dives, but not with enough reserve for me to feel comfortable.

 

[Texasguy]

I don't think you'll get much excitement out of scuba folk, you will at CandlePowerForums

 

[Caveeagle]

I don't think you'll get much excitement out of scuba folk, you will at CandlePowerForums

Yes, but there is fairly low traffic in the dive-light section of CPF. I do check over there once and a while, but have actually found SB to be just as helpful on dive related questions.

*Not really looking for a 20 page validation of my efforts.. Just trying to add a little solid information for anyone else trying to figure out if spending the extra money on batteries is actually worth it.

 

[kelemvor]

I have obtained many cheap (or free) 18650s by disassembling laptop battery packs. Yep, almost all laptops and netbooks have 18650 cells inside them. Usually when a laptop battery stops working, it's because only one cell has failed. The packs I've disassembled have either 6 or 8 batteries in each pack. Usually one or two will be bad, but there is a total cost of $0.00. Most laptop manufacturers don't skimp too badly on the cells, I've had good results from my recovered cells.

You do need to be careful if you try this at home.. The cells will be soldered together and you have to break the little piece of metal between each cell without damaging the side of the cell.

I may have to get me one of those fancy chargers, unless I can find just a meter. I've got two xtar chargers but neither of mine indicate battery capacity. Thanks for the link to that one!

 

[fmerkel]

The info on Ultrafire has been around awhile but finding good reliable info on the whole field can be more of a challenge. There are a lot more crap batteries than ultrafire. I met a dive instructor that had ordered personalized Brinyte DIV05V lights to sell to students. They came with a basic (no name) 18650 and charger. He added a BRC 5000mA cell he got from eBay. He sincerely thought he was doing them a favor with this higher capacity. I tested both for him (Opus analyzing charger). The 'stock' cell was ~2200mA. The 'large capacity' cell was 800mA. No surprise to anyone who knows there simply isn't any 18650 over 3500mA. I have a BRC 3800mA that is actually ~600mA and falling. I keep it around for testing.

Divers, in general, don't know a whole lot of specifics about lithium batteries, specialty chargers and LED's. Light and battery aficionados don't tend to know squat about dive lights. Crossover is a relatively small group. tbone and stuartv are good sources.

You might like this: Disassembly of some UltraFire batteries
I've seen some that had a tiny battery inside and the rest was some kind of powder....
You'd think it would be less trouble to just make a normal battery.

 

[BEVANJ]

I'm running NCR18650B 3400MAH cells in all my lights. They're great cells. High discharge, high charge (with the right charger). And more importantly, they are UNPROTECTED. This is very important.

With lithium batteries, it can trash the battery if you discharge it past a voltage certain point. So, what lots of battery manufacturers have done is to place a tiny circuit board on the top of the battery (hidden inside it), which cuts the battery off in the case where it discharges past a set voltage. This is a protected cell. Unprotected cells don't have this circuit board.

I don't know about you, but if I'm using a light for something like wreck or cave diving, I want the damn thing to work while I've got it turned on, regardless of it it's going flat. If there's ANYTHING left in the battery, I want the flashlight to turn that voltage it into visible light for me to use, not for some battery PCB (printed circuit board) to decide I'm about to harm the battery, and cut things off.

On the above logic, I've also got 10x NCR18650B cells so I can rotate them in my lights, and never jump in the water without a freshly charged battery. I also know I can get approx 1.5hrs in my dive lights on these batteries. Changing batteries on a rolling dive boat can be interesting though.


If you want a link to buy some cheap NCR18650B cells at a descent price, PM me and I'll throw you a link to where I got mine. They capacity test fine and are the real deal. Watch out, when it comes to high end (high capacity, high discharge) cells, there are TONS of fake ones out there.

P.S. As people have kindly pointed out, the cells advertised at 5000mah are B.S. I think the highest capacity legitimate 18650 cells you can currently get are about 3600mah (NCR18650G cells).

I'm running the Brinyte DIV05 lights fmenkel mentioned. So far, none have failed on me, and they've been to 60m+. Can't complain about that.