Hardcase batteries and rocks - my experience.

[Barmaleus]

Hi all!
Been actively using 2 hardcase batteries with my Kraton 4S v2.5 for the past 7 months or so. Mostly forest roads, but also some gravel. I also use a dust cover.

Recently noticed there are some rocks inside the hardcase - they got in through the holes for wires. Could not get the rocks out, so had to open the battery cases. CNHL did not recommend it, but I also did not want to keep using the batteries with rocks inside.

The cases are not hard to open. Just need to be careful. Got in, removed all the small rocks. The cells were clearly damaged by rocks - but did not look critical (or am I wrong?). Assembled everything; used gorilla tape to hold everything in place. Added extra tape around the wires, Layered in different directions to make sure there is as little open space around the wires as possible. Looks pretty solid now.

@Chinahobbyline - A suggestion from customer. Use better, MUCH tighter sealing around the wire holes.

Question to everyone: how are you making sure nothing gets inside the battery case? Maybe hot glue? Or is it too hot for this application?

Thanks!

 

[Chapinb]

Hot glue might not be flexible enough to keep the seal - only plug it some. Something like sho goo or e6000 would seal it better. Never opened a case before, has ever dawned on me there might be rocks in there. Is a good way to ruin the cell, or worse, cause a fire. Guess I got some sealing to do tonight!

If you can read the ir, compare the cells to each other. If 1 and 3 are roughly the same as 2, its ok. It dosent take much to short a layer of the foil and cause some damage or reduction in performance. I don't like the idea of using that pack with all the damage, but honestly, I probably still would.
Keep an eye on it reguardless.

Not surprised the manufacturer dosent want you to open the thing, is a liability. Too easy to stab an instrument through the foil and cause a real problem. Iv long thought there should be a little silicone or foam in there, so many of the packs have more wiggle room in the hard cases then Id like.


Edit - if you do add some sort of glue to the holes to seal it up, don't get much inside the case or on the foil. If the edge of the foil pouch gets glued to the case, and it shifts, youll rip the pouch eventually causing magic to be released.

 

[Barmaleus]

@Chapinb Thanks for your thoughts! Before the rocks got in, I also did not think about it. Now I know what to do with each new battery that has a similar construction.

So far both batteries been fine. Keeping an eye on the resistances.
The layered approach using tape worked really well, there is hardly any space around the wires now. Maybe some e6000 on top of the tape to seal it even better is something I'll try.

I wonder if total seal is bad tho? Maybe the battery needs some air to "breath"/get cooled? Thinking aloud.

 

[Chapinb]

Cooling isnt too much of an issue for our use case. don't know if they expand slightly during use, but even if they do and your case is air tight, I wouldnt be worried about it.

 

[RC Steve]

I have a tube of rubber silicone sealant I got from my local auto parts store. It's as sticky as Shoe Goo and is 100% waterproof. It would be perfect for sealing off your wire holes on your battery cases.

 

[Barmaleus]

rubber silicone sealant

Sounds good! Need to check out what our local shops offer.
Thank you for the idea!

 

[RCbuzz]

This is a downside with hardcase and not being able to see the cells. I have not come across one yet that seals properly around the wires.

I use cloth electrical tape. Seems to work fine.

Will try to get a picture up soon for ya.

 

[332_RC]

This is a downside with hardcase and not being able to see the cells. I have not come across one yet that seals properly around the wires.

I use cloth electrical tape. Seems to work fine.

The cloth electrical tape works pretty good. I've wrapped softcase batteries with it too.

 

[Barmaleus]

cloth electrical tape

Sounds like another great idea, thanks!

 

[ScaleJunkie]

silicone sealant .

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