My previous ships were sealed lead acid, so imagine my surprise when someone mentioned I should be sealing my LiPos…? Is that true? How are you sealing them?
R/C Subguy on Youtube has a quick tutorial on it. Basically he pours epoxy into the leads. View: https://youtu.be/0CYh_nZH-WE I use silicone caulk squeeeeezed into the cells
There ARE concerns, even if they are exaggerated. First off, I and many others have been using LiPos for years without problems. That doesn't mean you shouldn't do anything, though. The balance plugs can suffer corrosion issues, so if you want your LiPos to last more than a year or two, you'll either need to protect the balance plugs with dielectric grease, or blow them out after every sortie, or be prepared to occasionally replace a pack. I have lost a couple packs due to corroded balance plugs falling apart. That's a very small number in the grand scheme of things, though. The other concern is hard-case packs. The hard case can potentially trap water for days or weeks afterward, if you don't take steps to drain it. This is quite easy, literally just turn it on its side so the water can come out. But if you don't do this, you can potentially get corrosion problems inside the pack where you'll never see it. Lastly, if your batteries aren't going to be used for a week or more, you'll want to put them in "storage" mode. If a LiPo is stored at full charge or no charge, it will puff up and lose capacity over time. Storage mode charges or discharges your battery until each cell is within 40-60% of full charge, to prevent undesirable off-gassing. Personally, I haven't done much to protect my LiPos. I've lost four batteries total. One over-discharged when my ship sank, and the pump didn't shut off. One over-discharged when someone forgot to unplug a loaner boat before packing it in my car. One was deliberately destructively tested with a nail and hammer. And one balance plug failed due to corrosion. Four packs out of 30+ packs that I've been using for the past four years, that's pretty good. The only protection I've done is storage mode between monthly battles, and drying everything (boats, motors, batteries, etc) overnight with a box fan after battles.
I do nothing and they've been 98% fine for 5 years ish. Some of the oldest are getting a little swollen. The balance plugs do fall apart. When they're past saving I cut them off and solder on new ones. Soft packs dont really have water trapping issues. I prefer to add extra armoring inside the boat to protect the batteries vs buying expensive hard shell packs. Otherwise, everything Kotori said I agree with.