How Long Keep Batteries Charged?

[Varc]

How long can I keep my battery charged? Last week I was preparing my models for flying with the club Wednesday. But sadly the weather changed and we cancelled flying, so I didn't get to enjoy the day of flying. My battery is still charged up and I wonder how long can I keep it charged, or do I need to discharge it and how?

I like to keep the birds ready to go for whenever a Wednesday allows us to go flying.

[Chris g.]

l Wouldn't leave the batteries charged no longer than a few days before discharging Them.


If your charger has a storage mode just discharge them like that. Or take your heli in a garage spool It up for a little bit and then throw the battery on storage mode on the charger.

[Uriah]

I never let my batteries remain in a fully charged state for more than 24 hours. Leaving the batteries charged for extended lengths of time is not good on the packs, but even more importantly is it can be dangerous. A fully charged lipo has a much greater risk of causing a lipo fire than a lipo with a 20-30% storage charge. As Chris just stated, most decent chargers will have "storage" functionality, which will safely bring the battery down to a 30% charge state or somewhere thereabouts.

[megawhacker]

Take a look at table 3

http://batteryuniversity.com/learn/a...ased_batteries

[Uriah]

That article looks like it was primarily based on testing lithium-ion batteries.

[megawhacker]

Originally Posted by Uriah

That article looks like it was primarily based on testing lithium-ion batteries.

Glad you asked.


Is Lithium Polymer different?

The chances are that if you read this site, you've heard of Lithium Polymer (Li-Polymer) as a distinct battery type from Li-Ion batteries. The difference between them lies in the material used as the separator. Rather than an inert substance with holes covered in electrolyte, the separator is made of a micro-porous polymer covered in an electrolytic gel that also serves as a catalyst that reduces the energy barrier in the chemical reaction between cathode and anode. Therefore, Li-Polymer batteries allow for a slight increase in energy density. However, this advantage is offset by a 10% to 30% cost increase. Therefore, because the same materials are used for cathode and anode, Li-Polymer batteries follow the same chemical process as Li-Ion batteries and so are not a distinct class.

Because the solid polymer is flexible, it is possible to construct flexible batteries and batteries that can be easily formed into various shapes and sizes, even thin films. So you'll most often see Li-Poly used for batteries which are relatively thin (e.g. Nokia's 'hero' BP-4L battery used in a dozen devices) or oddly shaped (e.g. to fit round other components in a tightly packed phone).

Just as with Li-Ion batteries though, Li-Polymer batteries are slowly degrading from the day they are created, and are subject to the same harm caused by deep-discharges.

http://www.allaboutsymbian.com/featu...eries_work.php

Note the title of the article

How to Prolong Lithium-based Batteries

[Dustin Mustangs]

We have a whole forum dedicated to battery tech (https://www.helifreak.com/forumdisplay.php?f=31) with a great 'Lipo Basics' sticky that will answer all your questions and spur a bunch more (https://www.helifreak.com/showthread.php?t=336421).

No time to read now, get out there and fly that thing!

[thruster]

As I understand it, a lithium polymer battery is functionally a lithium-ion battery......even though most lithium-ion batteries are not lipos. How does THAT work for ya?

I'm trying to fly but it's always too much windy.

[megawhacker]

Originally Posted by thruster

As I understand it, a lithium polymer battery is functionally a lithium-ion battery......even though most lithium-ion batteries are not lipos. How does THAT work for ya?

I'm trying to fly but it's always too much windy.

Replace "lithium polymer" with Border Collie and "lithium ion" with "dog", delete a modifier, and you get,

As I understand it, a Border Collie is a dog....even though most dogs are not Border Collies. How does THAT work for ya?

. Sorry. I had to rework your statement. Slow day here in Pasco, Washington. Three hours until my shift begins.

[Uriah]

Thanks for the insight megawacker. I wasn't disagreeing with anything the article was saying, I was just noting that I only found "polymer" once in the article itself; so I wasn't sure how/if/where the data could be applied to lipos. That's interesting info. I've bookmarked it and will do some deep reading on it tonight. I love learning.

[kev0712]

Originally Posted by Uriah

Thanks for the insight megawacker. I wasn't disagreeing with anything the article was saying, I was just noting that I only found "polymer" once in the article itself; so I wasn't sure how/if/where the data could be applied to lipos. That's interesting info. I've bookmarked it and will do some deep reading on it tonight. I love learning.

Me as well, my friend. Never knew but on my way home as I type to Google like crazy and learn....thanx for the great info lipo god

[thruster]

Originally Posted by megawhacker

Replace "lithium polymer" with Border Collie and "lithium ion" with "dog", delete a modifier, and you get,

As I understand it, a Border Collie is a dog....even though most dogs are not Border Collies. How does THAT work for ya?

. Sorry. I had to rework your statement. Slow day here in Pasco, Washington. Three hours until my shift begins.

No worries.......if anything you made the point more clear.

[ss1-2013]

LOL...

[Scream]

I thought I had lost a stock 300x battery at the field.

Turns out it was inside my sofa!! It disappeared at full charge towards September 2013, and I found it last week, so about 8 mths of storage and some balancing and that pack is acting perfectly normal now after several test hovers using telemetry to confirm voltages.

I wouldn't recommend this, but I actually stored all 15 of my various pulse batts at full storage for the winter as I was hoping to get a chance to fly!! Approx 200 flights of testing and they all perform as expected this season... The heli gods are smiling on me. Don't try this at home kids

[Varc]

We've ben lucky with our lipo's so far. With weather changing every second in Colorado, it's hard to predict when we'll be lucky enough to fly or not. I'm either at work, or it starts to rain when I get off work and rains rest of the evening. So far, this coming week look's promising as Tuesday and Wednesday should be in the 80's and hopefully dry. My 300x's battery has ben charged since two weeks ago when I thought flying was a go.
I wonder if I should purchase a second battery for the model.

It seems the batteries for the Nano's are a lot more forgiving and they can hold forever and be ready at any second. But, the bigger batteries seem more questionable and more dangerous.

[Stomp560]

I have a Hyperion 3S 1800mah that is ever so slightly puffed, and the cells are whacky when charging, One is way ahead all the time, and one is way behind (i.e. at some point in the charge cycle I see: 4.09 - 3.98 - 4.14 ) But the high one will top out at 4.20 and sometimes blip to 4.21 as the other two cells catch up after a while and charging completes...)

Is there any way to smooth the balance of this battery out? I use a Hitec X1 AC Plus charger...

-Scott

[Varc]

Well, tomorrow look's promising, temps in the 80's and hopefully the winds will be calm.
Should I discharge the battery today and recharge it for tomorrow? Or just see how she goes tomorrow? I'd hate to bring it to the field and find the battery has an issue cause it's ben sitting charged too long.
I ask these questions cause I mostly fly micro's which don't seem to care as much as the bigger battery-powered birds.

[Varc]

Look's like flying is a go tomorrow morning. So, this afternoon I hovered the bird in the basement to discharge the battery, and now I'm re-charging it for tomorrow. Hopefully, all will be good. Thinking I should get a second battery for next week!