Robert P

I've got a couple of Zefal lights that use 18650 batteries. Inexpensive and put out a nice beam. I'm currently using NiteCore 189 3400 mAh batteries based on positive reviews. Do you feel there's a better 18650 battery?

rykard

a good reliable source for the uk would be good too.

Robert P

You mean as a source for the 18650 batts? They're hard to get there? Ebay isn't a good source?

no motor?

Panasonic and Samsung make good batteries. Mountain Electronics is a respected US source for them.

rykard

I was reading that there were some dodgy counterfit ones on ebay that caught fire ..

mibike

When I need information on batteries or chargers I check Candle Power Forums. I also check Flashlight information it is a site by a CPF user that does a lot of testing.

CliffordK

Hmmm... keep in mind there are both 3.7V, 3.8V, and 4.2V 18650 batteries. I'm not sure if they're the same with different ratings or different batteries. However, I'd match whatever you have in your device/charger.

I did have a battery pack that shorted out and burnt off some of the insulation. I got it disconnected before the batteries burnt. Still a bit scary.

My choice would be to find the highest power rated batteries on E-Bay. I'd just buy generic if I was going through E-Bay. I wonder if the same thing applies to batteries as MicroSD memory cards?

01 CAt Man Do

The only real 3400mAh batteries I know of are made by Panasonic so that's probably what you have. If you have authentic Panasonic cells you have the best 18650 batteries made with the highest capacity. What companies like NiteCore do is buy Panasonic cells, put their own protection circuit on the cell and cover it with their own label. This is a widely known ( and acceptable ) practice. The companies that do this probably have a contract with Panasonic that allow them to do this....assuming of course they are using genuine Panasonic cells. ( If you e-mail and ask them about this they will likely tell you the same thing ).

You folks in the U.K. might have problems getting Li-ion batteries imported. Since I don't live there I don't know how anal the UK customs are. Lots of Chinese sites sell authentic Panasonic and Samsung cells. Fasttech has a nice assortment of good brand names and are reasonably inexpensive. The e-bay vendor "Hunk Lee" ( Chinese ) has been a reliable source for "brand name" cells and cell-packs as well. Sometimes the Chinese websites have problems shipping the batteries via air mail. Most get through but sometimes there are delays. I've never heard though of Hunk Lee having any problems getting his product to his buyers. Been a couple years since I last used him though so things might have changed. Read his reviews and decide for yourself.

ItsJustMe

Actually only 3.6 and 3.7 volt (and some lower, but those aren't used in these situations) exist. Depends on battery chemistry.

4.2 volt cells are sold by people quoting the peak charged voltage. 4.2 is often the cutoff voltage for charging. As soon as the battery is under load it will drop below that. 3.6 or 3.7 is the nominal voltage for all common LiIon cells.

Types of Lithium-ion Batteries ? Battery University

The really awesome batteries are lithium iron phosphate, which are 3.2v per cell. Also pretty expensive and AFAIK nobody is using them in bicycle lighting. I know some people who have built ebike packs out of these and the performance is extremely good. I don't think any company is selling a commercial pack though.

WalkmanX

I have a few KeepPower 3400mah 18650s from Illumn. They have been working well.

ItsJustMe

Are those different than the Panasonics you get from Amazon with the same rating?