Battery Packs for Front/Rear Lights

[Tubamanandy]

Whilst I know wiring up a decent led front/rear light to the bike's battery pack is maybe the best option - I'm after a small lithium battery pack (independent from my main battery) and charger to power my front and maybe back lights.

Anyone know where to get them at a good price ?

 

[Deleted member 4366]

You need ones with low voltage protection built in. The problem is that the Ebay ones often say they have when they haven't.

http://www.ebay.co.uk/itm/2-X-UltraFire-18650-4000mAh-3-7V-Lithium-Batteries-Protected-Black-UK-/151106855878?pt=UK_ConsumerElectronics_Batteries_SM&hash=item232eaba3c6

To be honest, it would be a lot cheaper to buy one of those Ebay lights that come with a 4-cell battery pack and charger. The packs even have a BMS inside. You can get the whole lot for about £12. You'll probably pay more than that just for the cells.

 

[Tubamanandy]

"To be honest, it would be a lot cheaper to buy one of those Ebay lights that come with a 4-cell battery pack and charger."

Good point - would probably make more sense

 

[SAD12]

"You need ones with low voltage protection built in. The problem is that the Ebay ones often say they have when they haven't."

Now he tells me! I had the idea of not using the bike battery, but getting a 12v battery (4000mh) to power my rather splendid Banggood front light. I wanted to wire it separately to a three position switch on the handlebar, one for on, one for a flasher unit, (12v jobby) and one for off. This has worked rather well, even though I say it myself, but I was surprised when the light suddenly went off after just over an hour being on. The light is supposed to be 20w so I had calculated at least two hours. Measuring the battery revealed it was at 4.4 v. Argh, I've killed it! However it's charged up again and all is well. The flashing bit is great, it really makes the oncoming traffic hesitate and take a closer look.

 

[Deleted member 4366]

They may still be protected. They won't all trip together. Also, when they trip, there'll probably be residual or leakage charge. You'd have to put a load on it to see.