How many days do you keep your lipos at full charge?

[MLJones8]

So I'm still learning about these lipo batteries... I know I've read in the off season to keep them at about 3.9-3.8 volts. But what about during the season?

If you plan on running your boat every week or once every two weeks, do you keep your lipos at full charge, or only charge them a day before?

[bigwaveohs]

Charge them to 50% for storage and charge them to 95% the night before you use them...they will last longer.

[m4a1usr]

So I'm still learning about these lipo batteries... I know I've read in the off season to keep them at about 3.9-3.8 volts. But what about during the season?

If you plan on running your boat every week or once every two weeks, do you keep your lipos at full charge, or only charge them a day before?

I keep all my packs at a pretty much full charge during the 7 to 8 months out of the year (no real harsh winters here to keep me off the lakes) But I do take them down to 3.5 volts for the remainder of the year where they sit on the shelf. Discharged cells, down to a certain voltage,do not degrade cell capacity. Its taking them below that level and leaving them there that promotes chemical degradation. Then you cannot recover from the electrolyte depletion. Remember you are essentialy suspending neg ions in chemical bonds.

John

[MLJones8]

Charge them to 50% for storage and charge them to 95% the night before you use them...they will last longer.


This seems to be the common reply, meaning if my lipos are 2S 7.4 volts, then to store each cell at (7.4/2)=3.7 volts. I guess my question could have been worded more directly. What defines storage? A day? A week?


I keep all my packs at a pretty much full charge during the 7 to 8 months out of the year (no real harsh winters here to keep me off the lakes) But I do take them down to 3.5 volts for the remainder of the year where they sit on the shelf. Discharged cells, down to a certain voltage,do not degrade cell capacity. Its taking them below that level and leaving them there that promotes chemical degradation. Then you cannot recover from the electrolyte depletion. Remember you are essentialy suspending neg ions in chemical bonds.

John

Great thanks for the input... so John, I'd say you define storage as over a month?

[m4a1usr]

This seems to be the common reply, meaning if my lipos are 2S 7.4 volts, then to store each cell at (7.4/2)=3.7 volts. I guess my question could have been worded more directly. What defines storage? A day? A week?



Great thanks for the input... so John, I'd say you define storage as over a month?

As far as defined you could infere storage as windows of time as great as months, plural. I routinely leave packs unattended for 60, 90 days at 3.5 volts per cell. Been running those same packs for an excess of 3 years and no performance degradation. The important rule to remember is to not leave them fully charged, 4.24 vdc for extended periods. (Longer then 6 months). The industry recommends lithium polymer batts to be stored at 40 to 60% of capacity for extended periods (6 months and longer). My own opinion is that a lipo stored at a 50% charge for 2 years is going to be fine. But I have not done nor seen a study to put that in to fact.

I mistakenly stated neg ion suspension. That is incorrect. They are actually positive in their charge suspension. As current flows from positive to negative in a DC circuit. My bad!

John

[Simon.O.]

This is a good one to read. I learn more ech time I visit.
I see me (waiting for the wind to go) "storing" packs for 3-5 days at 4.20v as not a big drama.

If I am not going boating for 4-6 weeks :eek:, then I should drop them to 3.5 or close ? or should I only worry if I am going to store them for a few months.

Boating here is close to all year round, but I am a sook and like the flat calm water.

[ozzie-crawl]

i usally charge battries the day i run,after running them i leave them till the next time i run
batteries are usally between 3.7-4 volts after a run.
any more than a 4-6 weeks i charge/discharge to 3.6v a cell for storage

[m4a1usr]

i usally charge battries the day i run,after running them i leave them till the next time i run
batteries are usally between 3.8-4 volts after a run.
any more than a 4-6 weeks i charge/discharge to 3.6v a cell for storage


Amen Ozz. I think thats probably the best battery management technique. Unless you know your heading to the lake soon just keep them where they are after a day out and providing you know what they are down to.

John

[ozzie-crawl]

thanks john,plus its the easiest :buttrock:

[ED66677]

top quality chargers have a storage charge function witch charge at 60%, I bet that's the best!

[ozzie-crawl]

so do my cheapies from hobby king :banana:
they drop the pack to 3.6v a cell i think, i figure after a run my cells are between
3.7-4 volts so should not hurt any thing for a few weeks

[ED66677]

you're right ozzie, if the voltage is around 3.7V that must be perfect, but what if the voltage doesn't drop? I'm refering to the Rhino's where the voltage remains high even when the batt is empty!!!

[ozzie-crawl]

yes the turnigy packs do the same, makes lvc usless
but after a run if you check your packs the voltage will still be down
the packs just dont drop of under load as much as the low C rated batts that we used to run.
i very rarly balance my batts and dont use lvc, i time my runs, just use the count down timer on my tx and i then know how much mah i have used