How do poeple waterproof their batteries?

[joelw135]

Good suggestion, but even the smallest Pelican cases are large enough to accomodate far more AA batteries than I want to use.
I'm looking for a case for 2 or 4 AA batteries, as compact as possible.

A while back I found a small rectangle Tupperware type box that I used with an O-ring and Silicon seal for the wire to pass through.

 

[chris_m]

So dunno how important keeping them totally dry is. :shrug:

It's not - which is why I just use insulating tape round my battery packs, have an exposed balancer connector and an unsealed power connector. All getting a bit wet will do is give a high impedance short - yes some current will flow, but compared to the current you're drawing to power your lights, it's negligible. It's only electronics which get upset by high impedance shorts, hence why I seal my driver board in a proper case along with a waterproof switch.

 

[chris_m]

theyre run in parallel with a maxflex bost driver, another reason I don't want to change packs, would be limited to 3 li-on cells

Not at all - I run my bike lights from 4 LiIon cells - but wired 2s2p to give a 7.4V nominal pack.

 

[herulach]

Not at all - I run my bike lights from 4 LiIon cells - but wired 2s2p to give a 7.4V nominal pack.

Hmm, didn't think you could charge them like that? Or do you just need to make sure they're matched to start with?

Cemoi, I run 2x Romisen RC-I3 on my lid, butchered & epoxied back together to remove the battery tube & run off an external battery. Anyway, the moral of the story is, the pack is scavenged from a cheapy 3xAA headtorch. It's by no means dunkable, but I'm yet to see the inside damp.

 

[chris_m]

Hmm, didn't think you could charge them like that? Or do you just need to make sure they're matched to start with?

It's charging them in series which is the issue - and plenty of people do that, otherwise we'd all be using 3.7V packs. Having parallel cells isn't a problem at all, as they will auto balance. Anyway the series charging issue is resolved by using an external balancing circuit - I mention my balancer connector up there.

 

[RGB_LED]

Has anyone heard of waterproof (well, at least rainproof, I don't plan to go scuba diving with these) AA battery holder?
The holders sold by batteryspace don't seem to be waterproof at all.
And using Plastidip or the like won't make it, since I want to be able to take the batteries out of the case to charge them individually (i.e. not in series). So I need a case with a seal, like most bike tail lights have.

Cemoi, I'm in the same boat as you... I just built a 7.4v, 2x18650 battery pack with dc connector to power my two lights and I'm looking to waterproof the works as well. I do quite a bit of night-riding on single-track and it can get a bit muddy and wet so I agree that those battery packs will be no good, even in a light drizzle.

Dom's idea of plastidip is a good one as I have a couple that he built :thumbsup:, but I can't find plastidip here in Canada (unless someone can point me to a seller around here) so I have to go another route. I thought about heat shrink but can't find any that's large enough to wrap around the pack. As a dead-simple solution, I was thinking of purchasing a little neoprene camera case from my local sporting goods store (about $10 Cdn) and simply stuffing the battery pack inside, then strap the thing to top side of my downtube. I'll let you know how it works out but let me know if you find another, better solution.

Btw, can anyone comment about the whole issue of balanced charging? My 2x18650 as well as two other packs built with 8x18650. I'm now a bit nervous about just charging it as one unit. Any comments?

 

[herulach]

Cemoi, I'm in the same boat as you... I just built a 7.4v, 2x18650 battery pack with dc connector to power my two lights and I'm looking to waterproof the works as well. I do quite a bit of night-riding on single-track and it can get a bit muddy and wet so I agree that those battery packs will be no good, even in a light drizzle.

Dom's idea of plastidip is a good one as I have a couple that he built :thumbsup:, but I can't find plastidip here in Canada (unless someone can point me to a seller around here) so I have to go another route. I thought about heat shrink but can't find any that's large enough to wrap around the pack. As a dead-simple solution, I was thinking of purchasing a little neoprene camera case from my local sporting goods store (about $10 Cdn) and simply stuffing the battery pack inside, then strap the thing to top side of my downtube. I'll let you know how it works out but let me know if you find another, better solution.

Might be worth giving these guys a call. 2x18650 should strap nicely under the stem no? Probably keep a bit more mud off there. I know a lot of people put them in a saddle bag.

For smaller packs, a decent solution might be stretching a tube round them, fold it over & use vulcanising solution from a puncture kit to stick the ends down.

 

[RGB_LED]

Might be worth giving these guys a call. 2x18650 should strap nicely under the stem no? Probably keep a bit more mud off there. I know a lot of people put them in a saddle bag.

For smaller packs, a decent solution might be stretching a tube round them, fold it over & use vulcanising solution from a puncture kit to stick the ends down.

... EDIT... So, it turns out Home Hardware has this material in an aerosol can... Who knew? Funny, the last time I did a search for retailers, it only came up with Home Depot (US only). Thanks for the link herulach!

For the 2x18650: I will plastidip the battery to proect against moisture and mud. As for fitting pack to bike: underneath the stem was my first choice but I used heat shrink on the leads to protect them and they are a bit stiff so I don't want to bend them, also, the leads from the light end are a bit long and don't quite fit in that location either. I have tested out a way of velcroing the pack to the downtube just in front of my bottle cage and that seems to work - still have to test this out on single-track.

The 6xAA pack: still looking for solution to protecting the pack - I thought about the saddle bag solution but I'm not a fan of them so I still have to come up with another solution for it as I want to still be able to remove the batteries for individual charging...

 

[herulach]

Usually the distributor will be happy enough to tell you where they sell to though. are the AAs nimh? A 7.2V charger for nimh Racepacks isn't exensive, then if you put it into a tube you can still get into it at need, whilst still being able to keep it as a pack most of the time. Failing that a trip down to the local electronics supplier should do, I Imagine theyre mostly in standard sizes, and I know maplin (UK equivalent of radio shack) do one that would fit 6 aas nicely in the 2x3 holders

Thanks herulach, I already did a search and called practically every hardware store in my city and no one's even heard of the product, much less sell it. That includes the listing for Home Depot... I called them first and the US stores tend to carry different stock from Cdn ones so no luck there either.

I would use the tube solution but I have two battery packs that I want to protect: the 2x18650 and a second 6xAA - problem is that I want to be able to remove the AA's and recharge them individually. The search continues...

 

[RGB_LED]

Usually the distributor will be happy enough to tell you where they sell to though.

Yeah, bizarre that I couldn't find the Cdn distributor before... Anyway, like I said above, I gave the distributor a call and they provided me with 'Home Hardware' as a retailer for plastidip so I will give them a call. Thanks again!

...are the AAs nimh? A 7.2V charger for nimh Racepacks isn't exensive, then if you put it into a tube you can still get into it at need, whilst still being able to keep it as a pack most of the time. Failing that a trip down to the local electronics supplier should do, I Imagine theyre mostly in standard sizes, and I know maplin (UK equivalent of radio shack) do one that would fit 6 aas nicely in the 2x3 holders

Yeah, the AA's are NiMh and I have 2x3 AA plastic holder which is used to carry the batteries but I want to protect them from the elements. Hmm... do you have a link for a 7.2v NiMH charger? I currently use my Maha charger for the batteries but, if there is another charger that would perform as well but charge it as a pack, then that would be ideal. The only issue is that I am also soldering a 2.5mm dc connector to the pack so I don't know if the charger you are referring to would accept that connector...

Btw, are you going with the plastidip or tube route or something completely different to weather-protect your battery packs?

 

[Baulz]

... EDIT... So, it turns out Home Hardware has this material in an aerosol can... Who knew? Funny, the last time I did a search for retailers, it only came up with Home Depot (US only). Thanks for the link herulach!

LeeValley also sells it in Canada, but I can't find it on their website right now...

 

[dom]

Hi RGB_LED
A friend made a circuit up for me and sprayed it with the aerosol Plastidip.Came out real nice

I'd imagine it would need quite a few coatings compared to dipping -but would be a neater job in the end.

Cheers
Dom

 

[thwang]

Hi Herulach,
I build Li-Ion batteries and chargers, (well known on singletrack). Please mail me with what you are lookin for and I'll see if I can sort you out.

All Li-Ion Packs I build contain protection circuit boards along with additional re-settable and non-resettable devices.

Oh, I'm in the UK

hi how much do you charge for a 14,8 pack plus charger.
regards thwang

 

[RGB_LED]

Hi RGB_LED
A friend made a circuit up for me and sprayed it with the aerosol Plastidip.Came out real nice

I'd imagine it would need quite a few coatings compared to dipping -but would be a neater job in the end.

Cheers
Dom

Hi Dom, thanks for the info... I was speaking to my local hardware store about the difference between the aerosol and dipping versions - the aerosol version is special order and a bit more expensive so I settled for the dip version. I'm going to be making the attempt this week to see how it goes but thanks for the tip; I'll see the result of the dip verion and maybe try out the aerosol next time.

Btw, I wish I could say that I used the min-T a lot this year but I had two injuries so I've only been out on the trails a few times and I've been mainly doing road rides. I'm planning on hitting the trails hopefully this week for a night ride... How are you doing? How's the recovery coming along? Are you 100% now and riding again?