Submerged lipo

[Froggy]

When a boat sinks are the batteries/lipo?s pretty much done, if they are dead

[Xrayted]

Lipos are sealed and can actually survive being submerged in fresh water for some time, assuming the voltage isnt allowed to go too low. What are the cell readings? Anything 3V per cell or lower long term will result in permanent cell damage and cause higher IR.

Even short term below 3V causes damage, but the pack still may be able to be revived and balance charged back up either way for other "light duty" uses, such as a setup pack or other low current model.

I would not use a pack like that as a regular running pack again and place the normal high current draws on it, as the chances of having it puff, or in worst case scenario overwhelm the ESC caps from high ripple due to the higher internal resistance. This could result in an ESC meltdown/fire, and the voltage sag under load would cause the boat performance to be poor anyway

It will be fine if you can dry it out and the cell voltage is still sitting at 3.5V or higher

[Panther6834]

Adding onto everything said in comment #2, there IS the possibility that, once submerged in water, the LiPo might NOT be good anymore. While many LiPo packs are 'sealed', NOT all are sealed, or sealed probably. In other words, it IS possible to have a LiPo that either isn't sealed, or not properly sealed...and, in those situations, those packs need to be properly disposed of.

Case in point, I have several HRB LiPo packs (the soft packs w/ black & white label, w/ blue lettering) purchased through Amazon & eBay, which I've used in some of my boats for the past few years. NOTE: These are great for "general use", but not for racing. Until approx 15-16 months ago, I've never had any problems with them, including getting them wet. One of my boats - TFL Jet Boat - constantly had water in it (only recently discovered the cause, which is finally being fixed), to which the HRB packs always 'survived'. However, I had received some new HRB packs several months earlier, and it was one of those that happened to be in the Jet Boat that final run before I moved.

Anyway, as usual, the boat had a good amount of water in it, and the battery was submerged...and, to my amazement, despite me removing the battery from the water, and letting it "dry out", a couple weeks later (ie. after moving), I discovered that pack was now 'puffy'. Obviously, that pack was not properly sealed, and had absorbed the water. So, yes, while LiPo packs "should" still be usable once submerged, such is NOT always the case. Best thing to probably do is hold off putting the pack to 'storage' level for 2-3 weeks, put the pack aside until then, and when that time (ie. 2-3 weeks from the time the pack was submerged) comes, check it. If it's still the same, it should be good for further use...and, if it's 'puffy' (even slightly 'puffy'), it's time to properly dispose of it.


~ More peace, love, laughter, & kindness would make the world a MUCH better place

[jkflow]

Have to disagree, if they are not sealed them will instantly catch fire, puffing is actually normal and not really a concern unless they look like a like a pregnant balloon.
Puffing is overblown as a 'bad sign', it's normal out-gassing. By all means, over-stressing can cause this as well but that would also manifest itself by a higher IR.
In short, submerging alone will not damage anything in freshwater. Clean them out and you will be fine, in saltwater you might start shorting the terminals , flush as soon as possible but should also be fine if done quickly.

If you are not comfortable with your lipo, dispose of them (ballooned or not), not worth loosing sleep over it.

[Froggy]

The lips are completely dead there is no power in any of the cells they will not take a charge I keep getting a low voltage error on the charger.
The batteries look like brand new.
I tried to get them to take NiMh charge at 1amp no dice ???

[NativePaul]

They sound dead, but may not be chemically dead. A submerged LiPo will corrode it's aluminium tabs fairly quickly, you may have a tab corroded off and disconnected from the cell. If you're comfortable with opening the pack up do that and check the tabs, if not give it a salt water bath which will corrode the tabs away and provide paths inside the cells for the saltwater to neutralise the chemistry before disposal.

[Froggy]

I checked the tabs they look like new, the battery looks new other than Zero voltage