Hanperal 4 X 18650 Water Resistant Battery Pack Case House Cover for Bike Bicycle Lamp

Tried out this product to replace the sealed battery units provided with many bike lights. With sealed units you have no QC on the types and ratings of the batteries. With this unit, you have full control which means you should be able to better judge the performance of your bike lights. First test worked perfectly, the connection was easy and tight and the lights worked on full power for the 1.5hr night MTB ride. At the end, the unit still showed full power. I won't charge for the next ride and see if I can use this unit for multiple rides. STAY TUNED!The unit is obviously larger than the pre-packed but as the unit is water resistant (not proof), hopefully with upcoming bad weather, the unit will continue to work perfectly.One problem is that nowhere in the documentation does it confirm or deny that you can charge using the case. Q&A says yes but without confirmation in the documentation, it is a large risk to try charging LI-ON batteries.

I bike a lot, in rain as well as in clear weather and have also had problems with poor battery quality in the std battery packs that come with LED bike lights. I like the way I can buy high quality cells to put in this thing. I also LOVE the fact that it has an on/off switch for the USB. I would have liked the switch to activate BOTH USB and light connector, but it only affects the USB power. (Note to all LED bike light manufacturers: Either provide an on-off switch like this one does or DON'T put a 'power up' LED on the light - all that does is advertise to bike thieves "Come and steal me". Sheesh. (Maybe that's a considered business decision?)A note on the USB power connector. Some of my USB connectors will make connections as is, some need to be torqued slightly to the side to make a connection. This may be the reason that so many users complain about no power to the USB port. That was one major reason for buying this - my cell phone battery is weak and this provides a huge backup battery (but only if the connection is tweaked). I have another one waiting for me at home. I'll see if it behaves the same way.I can't address the water-proofness of the pack or connectors except to say that I've never had a problem even with non-watertight packs, but the construction give me some confidence that this will not be the weak link in the rain.

Upgraded to this after having a half dozen Chinese crap light batteries. Those things have zero quality control.This had a generous amount of Velcro and attached easily to my frame, the only reason I am leaving a 4 start is there is no rubberized back on the Velcro or the box which means it's going to damage the paint after awhile. I added some backing of my own to alleviate that but from a functional stand point it works fine. Some other reviews claimed it would disconnect from vibration, I took it down some pretty fast heavy root trails last night and it took a thrashing without any issues. I will update the review if I notice anything change!

I wanted to have four 18650s for my bike headlight so that I can both ride longer and charge less frequently. I wasn't sure about this case but at this price point it seemed like a worthwhile experiment. This was exactly what I was hoping for! My high capacity 18650s fit in it, it has a battery level indicator, the case attaches to my bike easily with the velcro strap, and it plugs right into my existing headlight. I highly recommend this!

Love it. It works great. I use this to power the headlight on my bicycle and my GPS unit ( my cell phone). The batteries that I put in it I got from an old laptop battery that I took apart. (Most laptop batteries are made with 18650 cells.) So far, the charge lasts longer than either of the previous 2 pre-packaged batteries I used.In one of the other previous reviews, someone said that the usb connection was faulty. There is an on/off button on the battery box that controls the usb connection only. I was wondering if he is aware of that.

Only drawback is that the 5v USB doesn't have a plug/cap so the entire battery box is no longer considererd waterproof....

I bought this specifically for usb powered lights and it did not work. The light just flickered and never came on. The other plug worked for powering a light so I know the batteries work, but the usb connection was faulty.I am unsure if this is a defect or a design flaw.Also, just a heads up that you will need to buy special batteries to fit this light.If the usb connection worked, I would be satisfied, but it doesn’t and I have two of those lights which work though other power sources.

Not sure what to say. It's a simple battery pack to use with your own 18650 batteries for a bike light. It's good quality and I prefer charging the batteries in a trusted charger. Other bike light batteries have to be charged as one in parallel so there is no way of knowing if all the cells are charged equally. This solves that problem for me.