lipo battery gets wet. what to do?

[jetskier]

I'm new lipo batteries. just like to know what I should be doing if my batteries gets wet, little bit or if it's soaked. and I read some where that never keep the batteries in full charge over 7 days. and try not to run it down till the LVC kicks in. Correct? Thanks again.

[St3alth_Frenzy]

Lipo batteries contain lithium, which reacts when it contacts water. So they must be AIR tight to not allow anything in. therefore, they are waterproof. the worst that can happen to your batteries is that the terminals that the wires connect to could corrode.

[785boats]

The best thing to do, if your batteries are getting wet, is to find the leak in the boat & fix it.
If however the boat has taken on water after a crash that's caused a split in the hull & the batteries are soaked, just cut off the heatshrink & dry out all the terminals & let it sit in the sun for a while. Then reshrink it.

[martin]

You should not go lower than 20% left in the pack when running, ie if you have a 5000mah you should not use more than 4000mah. If im not going to be running for more than a few days say i put them on storage charge which is around 50% charge then balance charge the day before im going to run again.

[jetskier]

You should not go lower than 20% left in the pack when running, ie if you have a 5000mah you should not use more than 4000mah. If im not going to be running for more than a few days say i put them on storage charge which is around 50% charge then balance charge the day before im going to run again.

50% storage charge. So I need to program that into my charger? Program capacity 2000mAh for 4000mAh battery?

[BHChieftain]

I've had lipos compeltely soaked a bunch of times. Just let them thoroughly dry before recharging. The worst that will eventually happen is the connector tabs on the inside will start to corrode, but that would take a while-- esp. if only freshwater. Salt water would be a lot worse.

Also note that your motor is also completely waterproof--- if it gets wet just squirt Corrosion X (availabe here at OSE) in it.

The components that hate water are the ESC, RX, and Servo. But you can buy traxxas waterproof servos, and note that the proboat and aquacraft ESCs are actually very water resistant (I've had these completely under water and they have never failed me). For the RX, you can put it in a baloon and zip tie it closed. On my shovelnose hydro which tends to get wet on the inside I have my RX in a Traxxas Slash waterproof RX box (also available on OSE) that works really well.

Because of the water resistance, I prefer the proboat and aquacraft ESCs (even though usually only 60-80A) compared to the cheaper chinese 120A ESCs... I can't keep those ESCs alive very well... so I just run my boats on 4S with a reasonable prop.

Chief

[martin]

Most chargers have a storage charge mode that you select which charges to around 50% capacity.

[jetskier]

Most chargers have a storage charge mode that you select which charges to around 50% capacity.

I just have a Onyx 235 (beginners lipo charger. lol!!) it does not have a storage mode but I can program it. I'll just program everything the same as the batteries and just 50% capacity will that work? thanks again.

[Heaving Earth]

If your batteries get wet, let them dry out.
Water is not gonna ruin them at all. I have had mine soaked many times without issue

[BHChieftain]

I think if you change the capacity number on your charger it will just really change the charge rate... ie, if you have 5000 mah packs and you tell your charger you have 2500 mah packs, it will still fully charge your 5000 packs but at .5C vs. 1C (would take twice as long).

Does your charger enable you to pick a target voltage? That would be better... you want 3.8v per cell (so for 2S1P pack, set the voltage to 7.6v).

Another way to swag it (which is what I do for my cheapo 1S heli packs on a trickle charger)-- if you know your charger takes 1 hour to fully charge a normally discharged pack, then you can put your packs on for 20min or so to put some mah back in. Better to be on the low side than the high side-- it is worse to store your packs fully charged vs. discharged-- you just want enough mah in there so the voltage level does not dip below the lipo kill zone...

The scenario you want to avoid is this--you fully charge a few sets of lipos, you go to the lake, and you have a problem with the boat and you are not able to use the lipos at all-- you need a way to discharge them. Best bet is to get a fully functional charger that has discharge and store modes.

But if you get in a situation where you can't discharge for a few days it isn't the end of the world or anything... and actually some people do store their lipos fully charged. I think this reduces the pack life and performance, but if you do it a few times it probably isn't a big deal so don't panic...

bye,
Chief

[madmikepags]

Lipos and your electronics should not be ruined by fresh water. I had my spec rigger under water for 6 months, everything still works (except servo) Motor speedo battery and receiver are still in working order. Wet lipos should have the shrik removed and placed in the sun to dry. Lipos should be taken care of but you don't have to be a LiPo Nazi, I raced batteries last week that I had fully charged in Oct,(they were still at 96-97%) and they ran the best they ever have. Dont worry about bringing you're batteries down to 5% or less I routinely do this on my offshore setups (as most people here know I love Offshore) just make sure you get some charge in them soon after you drain them (within a day or 2). Lipos stored with full charge will have a little higher resistance but once you run them and get a little heat in them they are fine. The most important part of running lipos is DON'T run them cold (60'F or less) this it bad because the IR is so high when they are cold heat builds up too quickly and then they have higher likelyhood of puffing. (this is even more prominent in older celkls and lower C rate cells) And I routinely charge my batteries 1-2 weeks before race day so don't worry about charging the night before. If I did that I would be charging from 8am to midnight, and I have over a dozen chargers. I have enuf batteries for each boat so I can run 3 heats and a practice run without recharging. So for example tomorrow I'm bringing 72 battery packs, could never charge in one day, much less even a week. If you have a few packs and you want to be vigilant and don't bring em down low or keep the strage charge at 50% this definitely cant hurt and will most likely be beneficial, but if you have a LOT of packs and just don't have the time to manage them "perfectly" they will be fine.

[jetskier]

Thank you all for the inputs. I got a pretty good idea on how to care for lipos now.

[BHChieftain]

... So for example tomorrow I'm bringing 72 battery packs, could never charge in one day, much less even a week.

Wow! And I thought me brining 16 packs for 2 boats to the race was excessive... I've decided that if I need more than that I'll just bring my charger and a generator or deep cycle battery to the pond.

I use a hyperion duo3 dual port charger and charge 4 packs on each port in // (8 at a time), so I can get 16 lipos charged in about an hour from storage level.

Chief

[madmikepags]

yes I can recharge but I run 3 classes my 2 daughters run 3 each and now my niece is racing with us and she runs 2 classes, only my older daughter is kinda self sufficient, with putting cells in and taping up so I reallly have no time to charge at the lake and forget when we go to big races I run 7-8 classes and each daugter runs 3 and 4 so no way to charge, I've gotta have enough batts to run all heats!!!

[Alexgar]

Don't overlook drying the balqn e plug either I've had they corrode to the point they wouldn't charge and I had to replace them