** LIPO BASICS ** Read me first!

[The WoodCrafter]

You CAN charge different cell count packs in SERIES but not in parallel.

[hidiver808]

What about discharging to a storage charge? Can you do all at once or will that over heat the charger? I have a iCharger 3010B.

[The WoodCrafter]

Originally Posted by hidiver808

What about discharging to a storage charge? Can you do all at once or will that over heat the charger? I have a iCharger 3010B.

What do you mean "do all at once"?

[hidiver808]

I currently only have three batts. Two 3300 6S and one 2600 6S. Can I hook all of them up to my paraboard and discharge them all, at once, to a storage charge?

I'm doing it as I type this...so I hope its ok. lmao

[The WoodCrafter]

Originally Posted by hidiver808

I currently only have three batts. Two 3300 6S and one 2600 6S. Can I hook all of them up to my paraboard and discharge them all, at once, to a storage charge?

I'm doing it as I type this...so I hope its ok. lmao

Yes, as long as all are 6S.

[hidiver808]

Awesome, glad to hear I'm not going to burst into flames over here. As usual, I can always count on this forum to help out the new guys. Thanks again.

[desertstalker]

Originally Posted by hidiver808

I currently only have three batts. Two 3300 6S and one 2600 6S. Can I hook all of them up to my paraboard and discharge them all, at once, to a storage charge?

I'm doing it as I type this...so I hope its ok. lmao

It will work, but it will take a LONG time, AFAIK that charger can do 50W discharge which is about 2A which will take over 2hrs to pull 50% out of those packs.

[sendittokeith]

thanks for the info, i sure wish they gave you this info in the lipo instructions instead of the cryptic verbiage they supply (which im sure is just wrapped around legal reasons).

I had ALWAYS charged my batteries after every flight and they would stay charged for 1-2 weeks, some for months. Didnt know i was killing them doing this, good to know and will save me time :0)

Finally, i just want to confirm, i am setting up a new 450 the voltages are 3.99, 4.01, 4.02 - so that means i can fly until the lowest one is ... 2.96V (3.7 * 20%) ?

I have been assuming the voltages were diff cause its a cheap tester, but i never once cycled a new lipo 5 times like you say and the LHS's never tell you to do that when you buy one (i guess they dont know or assume you do)

this is a REALLY NOOB question, but ideally if the battery voltage specifies its 11.1 shouldnt each cell at full charge be 3.7? Or is that just a ... approx since the battery voltage is usually well over 11.1 on a full charge?

'Generally a lipo flown down to 20% will end up between 3.6-3.8 v/cell. Never discharge for any reason below 3.0V/cell resting voltage. They then die forever.'

sorry for the long reply...

[SeanM]

Originally Posted by sendittokeith

Finally, i just want to confirm, i am setting up a new 450 the voltages are 3.99, 4.01, 4.02 - so that means i can fly until the lowest one is ... 2.96V (3.7 * 20%) ?

No, you should fully charge/balance the packs and then set your timer to something like two or three minutes and fly. Then charge them back up and note how many mah you're putting back into the pack. The goal is to consume no more than 80% of the pack capacity. So if you're using 2200 mah 3S packs, then you don't want to put in more than about 1750mah.. Doing so will damage the pack. So if you put back in 1000mah and flew for 3 minutes, then you know that you're consuming around 330 mah per minute. Do the math and you'll be able to squeeze another 2 minutes, making it a 5 minute flight until you're getting close to 80% discharged. When a pack is fully discharge down to 20% remaining, the cell voltage should be around 3.7 volts.

Originally Posted by sendittokeith

this is a REALLY NOOB question, but ideally if the battery voltage specifies its 11.1 shouldnt each cell at full charge be 3.7? Or is that just a ... approx since the battery voltage is usually well over 11.1 on a full charge?

No, 11.1 is not the voltage of the pack at a full charge. A fully charge Li-Po will be 12.6, so each cell would be at 4.2v. Never discharge a Li-Po below 3.6-3.7v... doing so will most likely damage the battery and it will never perform the same or could possibly need to be taken out of service.

[hidiver808]

Originally Posted by Slyster

For a more complete education.. be sure to visit tjinguys site:
http://sites.google.com/site/tjinguy...arging-how-tos

Cheat sheet for lipos

• Lipos are shipped with an inhibitor for safe transport. So always break in new lipos.. charge to full and then discharge to storage level (3.8V/cell) five times.
  

• New packs do arrive unbalanced sometimes. Do the break in procedure and they will be fine.
  

• Lucien Miller of Scorpion motors states it takes 8-10 cycles before a lipo realizes its full capacity.. so go easy the first 10 flights.

• Never store a pack fully charged for more than 48 hours.. some knowledgeable people find even storing fully charge more than 24 hours that they will never perform the same.
  

• Always store at ~50% (3.8-3.9 v/cell). Most chargers have a storage level feature that will charge or discharge as needed to get to 50%.

• Buy a cell spy.. very cheap and very important... these tell you the voltage per cell as well as overall lipo voltage. Here is an example of one. http://helidirect.com/maxpro-battery...ew-p-22041.hdx

• Follow the 80% rule. Take out no more than 80% of the lipos capacity.

• To figure out acceptable flight times to keep to the 80% rule... fly for exactly 3 mins (after breaking in the lipo) and see how much you put back in using your charger. Then you divide by 3 and now know many mah you use per minute. Adjust your timer accordingly.

• Generally a lipo flown down to 20% will end up between 3.6-3.8 v/cell. Never discharge for any reason below 3.0V/cell resting voltage. They then die forever.

• Many people today use parallel cables and high watt chargers to charge 1 to 6 packs (of equal cell count) for fast charging. The charger only needs to balance the packs as one larger capacity pack so you save a lot of time. Packs must be close in voltage to use this method. I use two 125Ah deep cycles to power my charger for fast field charges and with my iCharger 306b I can charge four 6s5000mah packs in 30 minutes. See Tinjguys site for much more info.
  

• Many ask about chargers that plug directly to AC... not really a good option.. since they only put out 50W. You really need a power supply... a great source (especially for high watt chargers) is http://feathermerchantrc.com.
  

Excellent write up and its helped me big time, thank you very much. I have a question about Tx LiPo batteries. I assume all these rules still apply? How ever, my DX8 does not have a storage charge setting. The battery lasts a long time (weeks) so I cant discharge through normal use.

What does one do about the battery being fully charged (or near full charge) for long periods of time?

[RedJoE]

Originally Posted by The WoodCrafter

Lap tops don't use LiPo batteries.
They use Li-ion batteries.
A little different chemistry.

Actually Lipoly and Lipo are exact same chemistry, don't believe the hype.

They are different than the old Lithium Ion batteries, but all the new devices out (like laptop batteries, phones, etc) all use Lithium Ion Polymer batteries, not Lithium Ion batteries.

Yes, your phone and laptop has the same type battery as your rc plane does, it is in a hard case though.

[desertstalker]

Originally Posted by RedJoE

Yes, your phone and laptop has the same type battery as your rc plane does, it is in a hard case though.

Not quite, the cell design is different, RC packs are optimised for high charge and discharge rates. Phone and laptop ones are optimised for max capacity and lifespan. Try to pull a laptop pack down at even 10C and it will be extremely unhappy.

The composition of the cells is slightly different, especially the membrane, to allow faster Ion transfer.

[RedJoE]

Originally Posted by desertstalker

Not quite, the cell design is different, RC packs are optimised for high charge and discharge rates. Phone and laptop ones are optimised for max capacity and lifespan. Try to pull a laptop pack down at even 10C and it will be extremely unhappy.

The composition of the cells is slightly different, especially the membrane, to allow faster Ion transfer.

Good observation, I would concur with this. I was simply implying that all the batteries in our phones, laptops, ipods, etc are of the same type(Lipoly), however you are correct, the actual construction between the versions of Lipoly are different, being much higher internal resistance in the versions for laptops, and ipods, much less C ratings, but much longer battery life and cycles too.

[Metal]

I have a couple questions.

Do you always refrigerate your packs between uses or just for long term? Is there an ideal storage temp? Is there an ideal usage temp?

[Slyster]

I never refrigerate my packs.. most don't. I just store in the garage in cement block bunkers. Doesn't get over 80F even in the summer.

[brentonasmith]

Originally Posted by Slyster

........ I always store charge all my packs after flying and it's time consuming hooking up all 6 packs in parallel etc. Thanks Dom.

This is exactly what I do and think this is best practice.

Refer Hyperion website "Storage - Lipo should never be stored fully charged, or with less than 50% of capacity remaining.* We strongly recommend Hyperion EOS chargers, as they have automatic STORE functions to insure that the packs are in the range of about 60%~70% capacity (3.78V~3.92V resting voltage per cell).* After returning home for the day, simply use STORE MODE to achieve this automatically. Batteries are best stored in a cool, dry environment (2~20 °C or 37~68 °F)."

http://media.hyperion.hk/dn/g3lipo/

[crustysphinkter]

Hi I've just got my eighth turnigy 6 cell 5000mah pack. When charging, cell 6 gets up to 4.15 volts then thats it. the other 5 all ballance out around 4.2. None of my other 7 packs are like this, some of them are in to 50-60 cycles. I do parallel charge my packs with an icharger 306b but when new a usually charge them on there own for 5 cycles or so. is there a problem with this pack? shall i put a few more cycles in to it or do I need to send it back? the IR is 1 on all cells

[desertstalker]

Originally Posted by crustysphinkter

Hi I've just got my eighth turnigy 6 cell 5000mah pack. When charging, cell 6 gets up to 4.15 volts then thats it. the other 5 all ballance out around 4.2. None of my other 7 packs are like this, some of them are in to 50-60 cycles. I do parallel charge my packs with an icharger 306b but when new a usually charge them on there own for 5 cycles or so. is there a problem with this pack? shall i put a few more cycles in to it or do I need to send it back? the IR is 1 on all cells

Cycle it a few times, it may come good. If not, you got a dud... happens (more often with turnigy but thats part of the reason they are so cheap).

[litehawkdown]

I just built a 4 port parallel charger lead for my 4 800mah Gens ace batteries for my Trex 250. Just wondering at what rate I should be charging all 4 at together? I have been charging them at 0.4A on their own. I feel like I could be higher then that. But now that I am doing 4 together can I up my rate 4x to 0.16A? LHS guy won't help me on this. He is dead against parallel charging.

[Slyster]

What charger do you have?

For your packs a 1C charge would be .8A per lipo... so four packs in parallel you would set it to 3.2A.

But with Gens Ace you can certainly charge at 3C to save time... so set it at 10A. All four packs will finish in around 20 minutes or so.

Parallel charging is the way to go these days. Don't worry about it.. just make sure your packs are all healthy and have roughly the same number of cycles... and if one won't balance well or if puffing.. pull it out of the loop and charge it by itself.