Warning Multi Lithium Battery Lights

[Peter69_56]

I purchased a new LED light that takes 6 x 1850 lithium batteries. They are 3 paralleled lots of 2 batteries in series. That is to say 3 columns of batteries, each being 2 batteries nose to tail.

What I found was that after a full charge, the batteries would be flat after a week with no use. In fact it would kill some of the lithium batteries. Contacted the supplier, and they ignored me (surprise, surprise)

I believe the reason is that when you have lithium batteries in parallel, they tend to have circulating currents due to the batteries having different internal resistance and slightly different voltages. All my previous torches had either 1 battery or 2 in series which is not an issue.

Has anyone else had this issue?

Beware the new big multi battery torches.

 

[Pao]

Aren't there diodes to protect the cells?

 

[Bobby]

Peter,
When properly designed & manufactured large Li packs are very stable and will sit for months without much discharge. Cells need to be matched and after charge they need to be balanced. Without doing this they not only will possibly discharge they can also be a fire hazard. We have packs that have been on our shelf for over 6 months that are still over nominal charge. Quality matched cells along with a quality charger with cell balancing is important. There are some off brand cells with crazy high mA ratings that I won't allow in the shop. Basically, from MHO, you get what you pay for when it comes to Li cells.

 

[Peter69_56]

Peter,
When properly designed & manufactured large Li packs are very stable and will sit for months without much discharge. Cells need to be matched and after charge they need to be balanced. Without doing this they not only will possibly discharge they can also be a fire hazard. We have packs that have been on our shelf for over 6 months that are still over nominal charge. Quality matched cells along with a quality charger with cell balancing is important. There are some off brand cells with crazy high mA ratings that I won't allow in the shop. Basically, from MHO, you get what you pay for when it comes to Li cells.

So do I buy quality batteries and more than I need, and after charge, then check voltages and match them all up? At this stage I am not sure if its the torch or the batteries. I am assuming its due to different batteries, although initially I did use all the same batteries, but they were just ebay batteries. Up to this point I have had no issues with lithium, however they all were either single appliance use or in series. This is the first item that uses paralleled individual batteries.

 

[Bobby]

I don't know what torch you are using. The best option is to have cells within a tenth of a volt to each other and balance charge all the cells together. Otherwise I would suggest purchasing protected Li cells if they will fit in the torch then leaving them out until you are ready to use them. It is possible that the driver for the LED's has enough draw, even with the light off, to run the batteries down.

The most important thing to know is that Li batteries can be a potential fire hazard if not properly cared for and protected.

 

[Peter69_56]

Ok so you are saying that perhaps the driver is not actually turned off? just something within the driver, thus consuming energy regardless of the switch position?

Torch is
2016 New Waterproof 100m 18000Lm 9x CREE XM-L2 LED SCUBA Diving Flashlight Led Torch Lamp 6x1

Buy Products Online from China Wholesalers at Aliexpress.com

 

[fmerkel]

It could be the torch......or it could be the batteries.....or it could be both.

Even cheap/crap batteries should not have gone dead in that short period of time, unless they are unbelievable junk. You have some kind of parasitic drain. Pretty much ANYTHING with the word [Fire] on it, Ultrafire being the poster child of this battery, are likely complete junk, and potentially dangerous junk. You should ONLY buy major brand name batteries (Panasonic, Sanyo, LG, Sony, etc) and they should be PROTECTED cells for a multi-cell light like this. If you were using protected cells the protection could have been tripped so they would show zero volts until the protection is reset. If you don't now what a protected cell is you shouldn't be playing with this kind of light.

So, it's probably the light. Buy unknown cheap Chinese lights and batteries and you take the risk of this kind of issue, along with poor workmanship, flooding, and they NEVER EVER live up to the output claims.

The only way around this is insert, use and remove the cells. Or put a new driver in the light, which is a task way beyond this discussion. Frankly, I think I'd go for a refund if possible and get a known decent dive light. Don't get sucked in by these exaggerated claims.

I hope you also have a good charger. The cheap unbranded ones are just that....cheap. Xtar, Nitecore, Liitokala are some good brands out there. IMO it's worth springing for a good analyzing 4-bay charger like the Opus or Liitokala

 

[StefinSB]

Weren't you getting hosed a while ago buying a cheapo Chinese compressor that never worked? In any case. This site has good batteries and chargers: LG 18650MJ1 Protected 3500mAh

 

[guruboy]

Are you leaving the pack disconnected from the light? You should avoid storing batteries in the light unless you can disconnect them physically from the electronics to prevent any standby current from draining the batteries.

If you are letting the battery pack sit by itself but with batteries connected to each other, they will kind of auto balance but it shouldn't cause them to continuously cycle current and drain.

Also, if you are in a situation where light is critical, do not buy the protected batteries. You want unprotected so that it will go as long as possible, even if it kills your batteries.

 

[KDAD]

Thought that is why diving in a critical situation you have a backup light. Or even a second backup light in a very critical situation.