I have been using some knock-off dive lights from China and they preform fine as long as I can get decent batteries for them. They have 3ea LED’s and accept 2ea 26650 batteries.
I have tried buying the high rated batteries off eBay and I am lucky if they work for one trip, I have been purchasing “TrustFire 26650 5000mAh” off of Amazon, they work most/some of the time.
The deal is I dive in rivers for fossils and once I drop to the bottom where the visibility is near zero I need the light to work for just over one hour. With the “TrustFire’s” even after they have been fully charged and the charger shows green they may not turn on the light or it just turns on for a few mins. When I get batteries that do work properly they run for usually 2.5hours which is two dives and would be great if it were consistent.
During email discussions with some of the light Vendor’s they say I should be using 26650 batteries capable of 20Amp + drain.
I am will to pay for quality batteries that I can trust but I have no idea where to acquire them with any confidence in the brand name, the Walmart does not sell any 26650 batteries.
Advice is appreciated!
I took a look at the battery you mentioned and also went to the manufacture’s web site for review.
If this is really the manufacture site they show two 26650 batteries, a “4200mAh 40A” & a “5200mAh 15A”. Do these models change quickly so the one showed on the “Mountain Electronics” site is most likely just not the latest model from Efest? How should I think about these specs the 15A model will last longer if it can drive the light, but the 40A model will defiantly drive the light but for a shorter time?
Those 15Amp and 40Amp stats really mean nothing as far as your dive light is concerned. I’d be really surprised if the light drew over 5amps. You want a quality cell and Mountain electronics almost always has fast shipping and lowest price. I personally would looks at the 5200mah button top protected cells. Efest does not make their cells, they buy from manufacturers like Panasonic, Samsung, etc. then they place their logo’s on the cell.
The “5200mah button top protected cells” only have 1ea in stock, I’m not in a hurry will not dive again until the water warms in the spring but would like to work out my plan this winter. They do have this same unit but “Unprotected”.
For my use, powering a dive light what is the value of “Protected” vs “UnProtected”?
PS: It is not unusual for the light to drain the batteries down until it stops working requiring it to be recharged. And there is never a dimming period it is either running at full brightness or dark.
If the light works as you describe, then it sounds like it has a low voltage cut off which is a good thing. When dealing with multi cell lights I like to have individual cell protection in case over time one battery degrades fast. So in the future after 10, 20, 100 recharges one battery develops more resistance than the other. This will cause the other cell to drain quicker over the first. Individual PCB’s will protect each cell. You may want to invest in a cheap meter just to check batteries every once in awhile. What ever two batteries you get for that light mate them together forever.
Ok I believe I understand why it is smart to use Protected batteries.
So my plan is when “Mountain Electronics” gets in additional “5200mah button top protected cells” I’ll get two for testing in my light, and if it works as expected.
When my setup is done I will be using 3ea for these lights on every dive, each light will have 3ea LED’s & 2ea 26650 batteries.
I will have two sets of the “5200mah button top protected cells” for each light
I will label each set of “5200mah button top protected cells” so as to always use them as mated pairs
Thanks very much for the information, I will update the post later after I test with these batteries.
Merry Christmas
If it’s the low voltage protection kicking in then the charger will reset it, and charge it. The purpose of kicking in is to stop the battery from going too low to recharge. If it’s the short protection then you’re drawing too much current for the PCB’s.
The lamp’s drain can’t be more than 2A if the light can actually run 2.5hours on one set of batteries.
Low temperature could be a problem. It increases cell’s internal resistance and may lead to premature low-voltage shutdown.
Is the water temperature 10°C or less where you dive?
High-current cells have better low-temperature performance, maybe this is the reason which they recommend 20A+ batteries.
Thanks for the response.
No the water temperature is always 17C+, I loose interest when the water gets colder than 60F!
I don’t have a lot of faith in the light Vendors comments, not being disrespectful but wholesaler’s may know less about them than I do. I put the lights to the test in a harsh environment, if they work for me they are pretty tough. The light design appears to be good, never a problem flooding and I bang them around hard, but I am wondering about current flow through the unit to the LED’s I was reading on a different board and they were discussing improving the current flow by sanding off some paint that should be allowing an electrical connection.
I’d say you need to add a good charger, preferably a good analyzing charger to your dive kit. +Some +of the Trustfires are good batteries, BUT you can’t trust (snort) you have good ones unless you can check them. There are crap fakes.
As stated it is unlikely your light is pulling much more than 2.5-3A (I have a 5-LED dive light and run it off a 2S2P 18650 4400mA cell just fine for 2 hours on high, almost 4 hours on med. On a dive I can’t much tell the difference between Med and Hi. FWIW we dive in the NW and the water is always 46-51*F.
Try not to run them until they die >>>> this is too low to do on a regular basis and contributes to early cell death.
Absolutely do NOT do this unless the cell or the light has cut-off protection, otherwise you are killing your cells……fast.
I ordered from Mountain Electronics 2ea EVVA 5200mAh 26650 Protected Button Top Batteries & an Enova ALL-80 8x Li-ion Charger.
1: Fully charged the batteries in the new Charger
2: Allowed flashlight to run in a bucket of water until light went out: It ran for 3hours and 40mins (Usually on TrustFire Batteries I got 2.5 hours)
3: I went through this cycle a total of 4ea times and the EVVA batteries consistently ran for 3hours & 40mins
4: Recharging the batteries takes longer than desired but I can work around this. I was hoping to recharge in 8 hours, but its taking a lot more than that, have not been able to watch it close enough to get a firm time but somewhere between 10-12 hours.
5: Note: These batteries are longer than the TrustFires, they work in my light but maybe too long for some other lights.
Questions
1: When the batteries are fully charged the lights go off for one battery and all three lights stay on solid for the other, how big a deal is this should I send one back?
2: Is it a good idea to put some conductive electrical grease where the flashlight screws together to improve the return current from the negative side of the batteries?
I am very pleased with the results thanks for everyone’s comments, I plan to purchase an additional 6ea of these batteries so I can run four of these lights at a time. If anyone has any additional comments or ideas please up date the post.
Thanks!
It has been a good while since I purchased these batteries and charger and I wanted to give an update in appreciation of all the good advice I received.
The “EVVA 5200mAh 26650 Protected Button Top Batteries” & “Enova ALL-80 8x Li-ion Charger” have both continued to preform very well.
Battery life has stayed constant, I am happy with these batteries, and would highly recommend them. Charger has preformed fine it really can charge eight batteries at once, but not 8ea of the “EVVA 5200mAh 26650 Protected Button Top Batteries” due to thickness of the battery. Can charge 6ea “EVVA 5200mAh 26650 Protected Button Top Batteries” at once with two additional 18650 which I use to split up the 26650. Very pleased with the charger.
One comment not necessarily negative, but something you need to know.
These batteries are a little longer and fatter than most other 26650 batteries I have tried. The length is no problem for my light but the thickness can cause them to be hard to get out of the light. Due to this the plastic cover on some of the batteries are starting to tear, not sure how serious this is, but so far it has not effected the battery performance.
Bottom line I would purchase these batteries and charger again, and I plan to.
Thanks for all the helpful comments!
Thanks for the feedback. It’s very valuable to know how stuff performs when it is actually used seriously.
What lights are you using? I have a couple dive lights but the only decent one is a Solarstorm DX4 4xXML, 2x26650. However i don’t really dive and haven’t done much more then put it underwater one night i was feeling for a late bath in the Mediterranean. I read good reviews about it.
Glad those are working for you. Protected cells are both longer and thicker than the same cell unprotected because of the protection pcb and the other extra layer of heat shrink needed to isolate the metal strip going from the pcb to the plus terminal from both the battery case inside and the metal flashlight case outside. The longer charging time is likely due to actually having the rated capacity rather than the inflated capacity of the trustfire cells.
