Should I "top off" my lipos?

[mwillack]

I think the answer is no, but I just want to make sure. I'm under the impression that once charged they lose very little of that charge. Thanks in advance for the help. :lol:

[kgfly]

It won't do any harm, you can recharge lipos from any state of discharge, but it won't be necessary in normal usage. They hold their charge for months on end with minimal self-discharge.

[istandalone]

it's good to hear that it won't hurt them to do this. sometimes, i forget which lipos have a charge and which ones don't, so i end up plugging in one or two that have a near full charge and charging them for a few minutes before i realize that they are already full. that's my only gripe with the bc-6- the fact that it won't tell you the resting voltage of a pack until you've started charging.

[kgfly]

Yes, that is annoying, all my other chargers let me see the pack voltage at any time.

[WillJames]

You can get a single FP V-Balance module. It has a "fuel gauge" on it that tells you the charge state at a glance. This is how I do it before even connecting the pack to the charger.

It is not good for the packs to let them sit for very long with a full charge unfortunately.

[mwillack]

What do you consider "not very long"?

[RC Accessory]

Check out this new item, the Bantam e-Station TWO-METER. One of the fetures is a pack and cell checker, as well as Watt Meter and Balancer.

http://www.helifreak.com/showthread.php?t=71296

[redgiki]

What do you consider "not very long"?

A fully-charged Lithium Polymer battery will permanently lose 20%-40% capacity in a year if stored with a full charge at 70 degrees Fahrenheit. If where you store it is cooler than this, the damage is less, down to 2%-4% per year if stored freezing, and much higher if stored in a hot garage. A fully-charged LiPo left in a hot car that reaches 150F or higher is dead in less than 1 cycle.

So it's tough to answer your question. It all depends on where you live, how tolerant you are of capacity loss, and so forth.

If my batteries are fully-charged and I don't expect to fly within the next 24 hours, I chuck them in the freezer in a plastic baggie. At 70F, you permanently lose 0.05%-0.1% capacity per day storing fully-charged.

I treat my LiPos just like my nitro fuel now: maximum 2 seasons. Plan on 100 flights per LiPo in the budget. Costs come out very comparably to nitros at that level, too.

[istandalone]

that is a nice unit, but already having a few balancing chargers and an eagletree i can't justify spending that kind of jingle for just the voltage readout feature.

[mwillack]

A fully-charged Lithium Polymer battery will permanently lose 20%-40% capacity in a year if stored with a full charge at 70 degrees Fahrenheit. If where you store it is cooler than this, the damage is less, down to 2%-4% per year if stored freezing, and much higher if stored in a hot garage. A fully-charged LiPo left in a hot car that reaches 150F or higher is dead in less than 1 cycle.

So it's tough to answer your question. It all depends on where you live, how tolerant you are of capacity loss, and so forth.

If my batteries are fully-charged and I don't expect to fly within the next 24 hours, I chuck them in the freezer in a plastic baggie. At 70F, you permanently lose 0.05%-0.1% capacity per day storing fully-charged.

I treat my LiPos just like my nitro fuel now: maximum 2 seasons. Plan on 100 flights per LiPo in the budget. Costs come out very comparably to nitros at that level, too.
Thanks so much for the very detailed info. I had no idea they had to be treated relatively gentle like that. So it's probably a good idea not to charge them unless you plan on using them. How low can I run them without damage, percentage wise? Thanks in advance for your help.

[Migs]

Here is a good guide:
http://www.rcgroups.com/forums/showthread.php?t=209187
Migs