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no1mad 09-21-13 12:28 PM

How to determine waterproofness of a battery pack?
As some know, I recently acquired a new light from DX (product link for reference).

While I have no intention of riding around in a monsoon, there will be times that I will most likely be caught out in the rain* and would hate to fry this thing because the battery pack or connecting plug got wetter than they should...

*Rain around here is basically any type of water falling from the sky, from a light drizzle to coming in sideways in sheets w/hail and the accompanying acoustical light show.

Looigi 09-21-13 04:07 PM

Is it specified as water/weather resistant? Many recognized brand name bike lights are specified as being water resistant and if they fail it's rectified under warranty. Barring that, you have to inspect it as best you can. Does it looked sealed? Are there gaskets or sealant everywhere there would need to be? Are there openings that look like they'd let water into the works?

1nterceptor 09-21-13 04:11 PM

My light has a similar connector and battery pack.
As a precaution I wrapped the battery in ziplocks,
then placed them back in the holster. Have used it
in a few downpours; no problems so far.

dougmc 09-21-13 09:43 PM


Originally Posted by no1mad (Post 16089911)
As some know, I recently acquired a new light from DX (product link for reference).

The battery pack on that looks just like the other packs I've gotten from DX and eBay and such -- cheap.

Assuming it's just like the ones I got, it's not water resistant at all -- riding in moderate rain could get rain in the battery pack and mess up the protective circuit and cause rust where it touches steel.

That said, it's really easy to make almost completely waterproof. Remove the battery from the fabric case, put a zip lock back around it, and then tighten it around the battery and let the cord come out of the hole, then wrap the excess bag around the cord and then tape it all down. Now it's almost waterproof, able to survive just about everything up to a short complete immersion (if you made it all tight and taped it off well.)

Oh, and don't worry too much about water getting into the plug. It can cause rust, but it won't short anything out or anything like that.

Booger1 09-24-13 12:05 PM

Low voltage batteries and flashlights will work when wet....they work underwater.

If you sink your car in a lake with the electric windows up,they will roll down if you push the button.

If you want to waterproof it,spray,brush or dip it in Plasti-dip.

Use dielectric grease on the plugs to prevent rust/corrosion.

dougmc 09-24-13 01:29 PM


Originally Posted by Booger1 (Post 16099466)
Low voltage batteries and flashlights will work when wet....they work underwater.

Well, except that most of our LED lights have driver circuits, and the lithium ion batteries have circuits that prevent them from over or undercharging.

How these things react to water is much less certain than how an old incandescent D-cell flashlight will.

As for what car windows will do, that's probably mandated by the safety rules -- so they limit the electronics required to control them and stick to tried and true (and still work when wet) switches and relays. Bike lights are not so regulated.

rumrunn6 09-24-13 01:41 PM

1 Attachment(s)
I put mine in an extra water bottle and covered it with 2 sandwich bags and 3 rubber bands. it was wrapped in thin bubble wrap to offer winter thermal protection. this time of year it rides in my rear rack trunk

niuoka 09-25-13 11:27 PM

I like the idea posted above about putting it in plastic dip,
however, for me , for now, the cords are long enough that I wrapped the battery pack with electrical tape, then put it in the little pouch it came with then have the battery pack in a zip lock bag and then in one of the pockets of my panniers, with the zipper zipped tight against the cord,
No issues yet....and it gets very wet where I live, Oregon
Prob over kill, but I don't want to find out one night in the rain

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