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Basic Lipo charging info...

bicyclemonkey

Flying Derp
Mentor
#1
OK, I've been using a Turnigy Accucel-6 charger. This is a 50watt 6amp charger. From my understanding, for example, I can charge a 3s 2200 2c lipo at 4.4amp charge rate (2.2ah x 2c= 4.4 amp charge rate).

So, charging at this rate still takes like an hour and a half to charge. This is on the "regular charge" setting, not the "fast charge" though.

I guess my question is: Will getting a 100 or 200 watt charger speed up my charge times drastically? Is using the "fast charge" setting going to hurt the longevity of my lipos and how much faster would they charge? I'd like to be able to take a charger to the field and not have to wait 1.5 hours for a battery to charge.
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#2
At a 1C charge rate (normal) it should only take an hour.

I myself wouldn't charge a (lipo) battery pack I cared about more than at 1C. It can hurt the battery. The only reason I could think it would take longer, is that you might be charging at a balance rate every time. I only balance every few charges.
 

bicyclemonkey

Flying Derp
Mentor
#3
So at 1c, that would be 2.2a charge rate for the 2200mah lipo?

The crazy heli guys at my field have these super expensive chargers and power supplies and they're charging like 5000mah or higher lipos in like 15-20 minutes. I don't want to drop $400 on a charger but I'd like a little faster charge.
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#4
I use 2.2a for my 2200's and they charge in under an hour.

Are they charging lipos, or the new LiFePO4 batteries?

I know there's a chemistry other than lithium polymer that they can do a dump charge for. The batteries have a little less voltage per cell, so they are heavier packs for the voltage, but they can be charged super fast.
 

jetpackninja

More combat please...
Mentor
#7
The only way to charge faster is to charge at a higher rate.
With the charger you have (a great charger- it's what I use) You have the capability to charge at up to 6 amps (theoretically anyway, I think the charger uses some of that itself)

Some of the new technology batteries, notably Gensace (HobbyPartz) and Nanotech (HobbyKing) and some other brands that most of us refuse to pay the premium for, can be charged at much higher rates. Conventional wisdom says that you should still charge at a 1C or lower rate. Having said that, -=If you do this do at your own risk warning=-at the field I often charge my 2200mah batteries at a higher rate and can fill one in about 20 min or so-=If you do this do at your own risk warning=- When charging at the field I always use the Fast Charge mode. This is faster because in normal charging mode it charges the battery most of the way up, then drops to a lower charge rate to top them off. The Fast Charge just goes until they are full and quits

At home I ALWAYS balance charge and many times at below 1C because I often use a parallel charging board

Sorry- Short story- Big expensive charger will not charge your batteries any faster at 1C than what you are using.
You can, if you are willing to stress your batteries a little more, charge them faster if your batteries are rated for higher than 1C charging

So at 1c, that would be 2.2a charge rate for the 2200mah lipo?

The crazy heli guys at my field have these super expensive chargers and power supplies and they're charging like 5000mah or higher lipos in like 15-20 minutes. I don't want to drop $400 on a charger but I'd like a little faster charge.
 

jetpackninja

More combat please...
Mentor
#9
A higher wattage charger will allow to charge at higher Amp rates.
So for instance- the 5000mah batt you could charge in about an hour at 5 amps with your 50 watt charger- If you want to charge them faster, your gonna need to charge at higher than a 1C rate.

So with a 500 watt charger you can charge up to 20 amps (way faster- that's what your crazy heli guys are doing)
Bigger batteries (more mah), lots of cells want to charge them higher than 1C- Thats when you are gonna want a charger that will do more watts (and amps)

What kind of lipos are you using?
How fast do you realistically want to charge them?
Do you charge one battery at a time or do you parallel charge?
 

bicyclemonkey

Flying Derp
Mentor
#10
What kind of lipos are you using?
How fast do you realistically want to charge them?
Do you charge one battery at a time or do you parallel charge?
I just use Turnigy and Zippy lipos. I've only ever charged one at a time on my Accucel-6...does it have the capability to charge more than one at a time?
 

jetpackninja

More combat please...
Mentor
#11
Ok, the regular Turnigy and Zippy's You NEVER want to charge at more than 1C

-=WARNING try at only at your own risk. LIPOs can be dangerous. Proceed only if you understand and are willing to manage the risks involved=-
Do some searches on parallel and series charging for Lipo batteries. Please don't take this as a negative, it's not meant to be so.
I send you to the powers of the Google machine because there is a LOT of information out there. Go in with your eyes open.
Parallel and series charging can be safely done but there are a lot of precautions that need to be taken to safely do so.
Lipo charging is one of those things that can create a LOT of havoc if something goes wrong
Series charging would let you do two at a time.
When you plug two 2200mah into a series adapter the charger "sees" one 6s 2200mah battery

Parallel charging would let you do 6 at a time.
When you plug two 2200mah into a parallel adapter the charger "sees" one 3s 4400mah battery
When you plug three 2200mah into a parallel adapter the charger "sees" one 3s 6600mah battery
When you plug four 2200mah into a parallel adapter the charger "sees" one 3s 8800mah battery and so on

Twins Series adapter (didn't have great results with this method, lots of heat generated on the charger)
http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=10993

This is the setup I use
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=14856

setup.jpg
 

bicyclemonkey

Flying Derp
Mentor
#12
I like the one in the second link you posted. Looks like I'd need to make an XT-60 to deans adapter since all my batteries have deans on them and I noticed on that parallel board it has XT-60 soldered to it.
PCB004.jpg
 

jetpackninja

More combat please...
Mentor
#13
Nah- HobbyKing has one that uses T plugs too
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=15237

please make sure you read up and understand the risks etc
you could theoretically ruin (puff) a battery just by plugging them into the board if the voltages are great enough difference.
I always match mine fairly closely with a small cell checker an often charge two or three at a time- seldom ever more
 

PaulT

New member
Mentor
#15
This will be my one and only PUBLIC SERVICE announcement for today.
As an officer of my local Fire Department and a a full time Paramedic, please educate yourselves and constantly
review charging procedures every time you charge.
One of the first things I learned about LiPo's is listed here;

http://www.hooked-on-rc-airplanes.com/lipo-battery-packs.html#c

THESE BATTERIES ARE POTENTIALLY LETHAL WHEN NOT PROPERLY USED!

Never charge beyond 1c and always monitor while charging. Don't just plug them in and leave your shop/garage/basement and expect the fire department to save your silly butts..we do it, but we don't like to.

I know this from experience....
 

JimCR120

Got Lobstah?
Site Moderator
#16
Please correct me if/where I am wrong. As I think through this I think of my Turnigy charger that charges through the balance port which perhaps might make a difference in how this plays out electrically. I agree with what you say about the parallel setup and the voltage not changing while the charge capacity does but if this were to be done with the (balance) ports electrically in series, it seems that the voltage handling might be different.

Remembering way back to BE&E (Basic Electronics and Electricity) I remember that voltage drops in series are additive and in parallel are identical.

Thoughts?
 

colorex

Rotor Riot!
Mentor
#17
Important Note:

Don't charge your batteries immediately after discharging them. Let them rest for a while, or you will damage them.

Edit:

Don't charge your batteries immediately after discharging them if they are still warm. Let them cool down for a while, or you may damage them.
 
Last edited:

fred0000

Senior Member
#19
Why? And how much is "a while"?
i'd also like to know why. everyone at the race track will put the battery they were just racing with imediatly on charge when they come off the track. I have yet to see any issues or run into an issue myself.

if the battery is warm or hot, I understand letting it cool down a bit first but even then charging at 1C really doesn't generate aall that much heat on lipo's.
 

colorex

Rotor Riot!
Mentor
#20
Well, the charger says so.

Also, I plugged my battery into my charger, right after using it, and I got battery error (three flashing red leds). I plugged it into my battery tester and I also got error. I then remembered the warning in the manual, let the battery rest for a while (a while for me was 5 minutes) and then everything was OK. Oh, battery was not even warm.

I don't know if it can damage your battery, but better be on the safe side.