Maximum Charges per day for Lipo's ?

[sacko]

Just doing the Math on that.

5 flights a week = 240 flights a year.
£160 6s 5000 / 240

= £0.65p per flight.

If the lipo gives up in that time, back it goes.

Obviously startup costs aren't cheap, but it all the hear holds it value.

[SamS]

What i do is, NEVER DISCHARGE BELOW 20%. If you do then throw the lipo away. And charge to 80%, then on the day to 100%.Gets the most outta your lipo

I don't think there's any need to throw a lipo away if you go below 20%, from what people are saying it seems don't allow it to go below 20% as it can discharge in certain temps.

I certainly won't be ditching a lipo just because I used it for a bit too long.

Thanks

[sacko]

Just looked at the Thunderpower site;

Thunder Power RC batteries are still proudly matched, assembled and supported in the USA and backed by an industry-leading full 2-year warranty and 50% off damaged battery replacement program coverage.

[muscleflex]

Just looked at the Thunderpower site;

how can you tell it's damaged?
like if it's physically damaged? or cells not charging? that kind of damage?

[sacko]

Cell damage, if it isn't holding charge or delivering the power it should. Puffing is probably a good indication as is heat produced.

The 50% discount is on crash damaged
packs.

[cjcj1949]

The discharge to 20% is an arbitary figure. From what I've seen it is more about how hot the lipo gets on discharge. The less you discharge both in current and in depth the less it warms. I get 5 minute flights on a 450 using a 3S 2200 and stop if the volts drops below 3.6 or 3.7 on load. The drop in volts gives a good measure of how the battery is doing. On a hot summer day the battery will last a lot longer than in the winter.

I cannot see any reason to allow a lipo to cool down. This was needed with NiMhs because of the way end of charge was detected, but lipos like being warm, say 30deg C. If the lipo is much more than that then it needs to be used less.

It does seem strange that a warm lipo performs better than a cold lipo and yet we know that a poor lipo heats up and doesn't last as long as a good one. If in the cold you prewarm a lipo or use it gently for a minute and then fly it lasts and behaves much better.

We had a long discusion on cold batteries getting overcharged and there was no evidence for this. Volts do not change as a lipo cools. It is not a good idea to use a cold lipo though or to store them fully charged, but they last longer if stored cool rather than hot, just as they last longer if stored at a lower voltage.

Much of the lipo knowledge is very dubious, especially as lipos have changed so much for the better. But there is a general principle with all things that they tend to wear out and this is certainly true of lipos. The other principle in reliability is that by life is increased by derating. From the derating argument high C batteries should last longer than low C batteries. We don't know though what has been done to increase the C rating, it might be something that increases reliability or it might be the opposite.