Hardcase Lipo in Boats?

[Shane_744]

I just got my new 7.4v 5000mah lipos but they are hardcased. I clearly ordered softcase ones on the invoice.
Anyways, they still fit in my Vac-U Pickle. Just wondering if there are any issues running hardcase lipos in boats or in this hull. I did a search and found some info but not a direct answer to my question.

THanks.

[sailr]

Nope. Should work fine. Just a bit heavier as far as I know. Others around here are using them OK.

[Raydee]

The only bad thing I heard is that if water gets into them you can't take them apart like soft case lipo's to dry them out. If the tabs corrode then you will have issues.

[sailr]

Hmm, good point!

[Shane_744]

Thanks guys. I guess I got the deal. The hardcased ones are smaller and more expensive.

Quick question. They both are sitting at 7.84v's. I need to throw them on the charger for a bit @ 5.0amps and finishing charging them?

[Raydee]

Yes you will need to charge them to 4.2 volts per cell or 8.4 volts per pack to be fully charged.

[Shane_744]

Thanks guys. One more question.

Does it matter when I put packs back on the charger to charge them up?

Example: I run a 2c pack down to 7.0v. I know about not over discharging them but as long as the are not fully charged to 8.4v total, I can charge them back up no matter what voltage i discharged it too, ie 6.8v, 7.3v, 7.6v, etc etc...

[jcald2000]

Yep, but don't take down below 7.0 volts or you will take life out of them. Thats 7.0 volt under load!

[Shane_744]

Gotcha. Is that a good volt (7.0v) cutoff for 2c's? (To keep the cells healthy?)

[jcald2000]

For 2S (2cells in series=14.4 volt total pack} that is correct.

[sailr]

Huh? Typical cutoff setting for lipos is 3.0-3.2V . That means you can discharge a 2S pack down to 6.0-6.4V without any harm. What's this 7.0V stuff?

AND 2S = 7.4V, 8.4 fully charged! NOT 14.48. That would be TWO 2S packs in series.

[Jeff Wohlt]

Or you can pop them apart and have the cells. They are easier to seal but they also hold heat...maybe not a bad thing in some cases.

[Shane_744]

Huh? Typical cutoff setting for lipos is 3.0-3.2V . That means you can discharge a 2S pack down to 6.0-6.4V without any harm. What's this 7.0V stuff?

AND 2S = 7.4V, 8.4 fully charged! NOT 14.48. That would be TWO 2S packs in series.

Talking about discharging only to 7.0v's to keep the cells good. I know about 6-6.4v cutoff. Just didn't know if guys go above that to prolong the battery's life.
Or just should I run the piss out of them to 6.0v?!!!

Or you can pop them apart and have the cells. They are easier to seal but they also hold heat...maybe not a bad thing in some cases.

Thanks. I will see how hot they get before I bust them apart. It would help me get them up a little further in the hull.

[jcald2000]

The new 35C cells don't like to be taken down below 3.5 v per cell under load. Its your money.