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        Discussion Explain Please!

#1 JQuite Jan 31, 2013 12:41 AM

Explain Please!
 
Okay, so I guess I'm a little slow apparently. I don't understand how to charge lipo's. To make it simple.

I have 2200 mah 3s 30c lipo batteries for my T28 trojan.. Apparently I've been charging them wrong? At what amp should I be charging these at? EFLB22003S30 It says on them 3C charge rate, whatever that may mean.. Why can't they just simply put the amp rate on the battery? Any help would be GREAT thanks!!

#2 still4given Jan 31, 2013 02:04 AM

2200 mAh @ 1C = 2.2 amp charge. So, 2200mAh @ 3C = 6.6 amp charge

#3 abenn Jan 31, 2013 02:31 AM

As still4given has said.

3C charge rate will theoretically charge an empty pack in 20 minutes, but it's better for the pack if you can use a lower rate and take longer. Until recently 1C (= 2.2A for your packs) used to be the charge rate for most packs, and is still recommended if you can afford the time, or if your charger can't supply the amps needed for higher rate balance-charging.

Ooops, I've just checked your packs on the internet http://www.horizonhobby.com/products...FLB22003S30#t2 and it says quite clearly (see the Specs tab) that maximum charge rate is 2.2A, which is 1C. So, where did you see the reference to 3C charge rate?

#4 RC Man Jan 31, 2013 04:46 AM

Most LiPo’s list the charge rate on the label. Perhaps the newer ones have been upgraded. Most LiPo’s these days can be charged faster than 1C.

#5 ggcrandall1 Jan 31, 2013 05:14 AM

Quote:

Originally Posted by JQuite (Post 23987197)
Okay, so I guess I'm a little slow apparently. I don't understand how to charge lipo's. To make it simple.

I have 2200 mah 3s 30c lipo batteries for my T28 trojan.. Apparently I've been charging them wrong? At what amp should I be charging these at? EFLB22003S30 It says on them 3C charge rate, whatever that may mean.. Why can't they just simply put the amp rate on the battery? Any help would be GREAT thanks!!

New to LiPo's. Here is some good reading.
https://sites.google.com/site/tjingu...arging-how-tos

Glen

#6 grimbeaver Jan 31, 2013 09:58 AM

Quote:

Originally Posted by abenn (Post 23987589)
As still4given has said.

3C charge rate will theoretically charge an empty pack in 20 minutes, but it's better for the pack if you can use a lower rate and take longer. Until recently 1C (= 2.2A for your packs) used to be the charge rate for most packs, and is still recommended if you can afford the time, or if your charger can't supply the amps needed for higher rate balance-charging.

Ooops, I've just checked your packs on the internet http://www.horizonhobby.com/products...FLB22003S30#t2 and it says quite clearly (see the Specs tab) that maximum charge rate is 2.2A, which is 1C. So, where did you see the reference to 3C charge rate?

Stop giving incorrect information. It will not harm the battery to charge at 3C if it is rated for it, please provide proof it will. Also he never said he's using the Horizon Hobby battery so why are you quoting the specs from it?

#7 goldsworthy Jan 31, 2013 10:02 AM

You cant say that charging at 1 C wont help your battery last longer. Why be in such a hurry? Just buy 4-5 batteries and you wont have to charge as often. My 6 S 65-125 batterys cost over $100.00 each I want them to last.

#8 Dr Kiwi Jan 31, 2013 10:28 AM

Quote:

Originally Posted by grimbeaver (Post 23989923)
Stop giving incorrect information. It will not harm the battery to charge at 3C if it is rated for it, please provide proof it will. Also he never said he's using the Horizon Hobby battery so why are you quoting the specs from it?

He gave the correct catalog number for E-flite packs sold by Horizon Hobby.. but I agree that specs say max. charge rate is 2.2A/1C.. he said that it says on the pack 3C, but I can't find an image which shows that. [EFLB22003S30 It says on them 3C charge rate]

#9 grimbeaver Jan 31, 2013 10:36 AM

Quote:

Originally Posted by Dr Kiwi (Post 23990224)
He gave the correct catalog number for E-flite packs sold by Horizon Hobby.. but I agree that specs say max. charge rate is 2.2A/1C.. he said that it says on the pack 3C, but I can't find an image which shows that. [EFLB22003S30 It says on them 3C charge rate]

My apologizes, I'm a little blind today I guess. Would not surprise me if they are finally marking them 3C. I'm sure they have been able to take it for years. They finally realized they are loosing sales due to the conservative marking.

#10 abenn Jan 31, 2013 02:08 PM

My TP Prolite packs are worse -- they say 1C on the front, then 5C in the small print on the back, and on their web site :rolleyes:

I didn't say it would harm the battery to charge at 3C if that's what the manufacturer rates them for. But I said, and still believe, it's better for the pack to use a reduced rate if you have the time :)

#11 JQuite Feb 01, 2013 03:30 AM

It says on the battery pack itself "3C Maximum Charge Rate" I'll post a picture later.. And yes I am using the E flite Horizon Hobby battery EFLB22003S30...

#12 abenn Feb 01, 2013 06:18 AM

OK, to answer your original question, you can charge them at any rate up to 3C, which for a 2200mAh battery equates to 6.6 amps, provided your charger is a good balance charger and can put out that many amps.

It's my belief that 1C (2.2 amps for 2200mAh) is kinder to the battery, even though it can take 3C :)

#13 Jimob23 Feb 03, 2013 04:03 AM

Quote:

Originally Posted by abenn (Post 23999062)
OK, to answer your original question, you can charge them at any rate up to 3C, which for a 2200mAh battery equates to 6.6 amps, provided your charger is a good balance charger and can put out that many amps.

It's my belief that 1C (2.2 amps for 2200mAh) is kinder to the battery, even though it can take 3C :)

Not trying to start a bun fight with a close neighbour but can it then be assumed a continuous discharge at the max charge rate is acceptable ?

Cheers Jim
:)

#14 abenn Feb 03, 2013 05:49 AM

I suppose your point is we don't usually believe the quoted discharge ratings -- or at least, if we do, we don't usually continually run at them -- so why should we believe the quoted charge rate?

Personally, I don't. Which is why I keep saying that 1C charge is kinder to the battery ;) I also don't discharge at more than about 12C in any of my models -- even edf -- even though all of my batteries are rated for 25C and over.

But there is certainly enough anecdotal evidence on this forum that cells rated for xC can be charged safely at xC provided a good quality balance charger is used. In fact, I think many manufacturers make that qualification about the charger when they quote charge rates higher than 1C.

Maybe manufacturers are more careful when specifying charge rates because of the potential consequences if the battery vents and flames during charge. If the battery can't live up to its discharge C rating, often it simply means that it won't deliver the amps, so you don't get maximum power. If it does vent and flame due to going over its discharge C rating, at the worst you usually only lose a model, not a house or car.

Disclaimer: Before anyone jumps down my throat, I'm only saying what I do and believe. I'm not recommending that everyone must keep to 1C charge and 12C discharge if their batteries are capable of more :D

#15 everydayflyer Feb 03, 2013 06:35 AM

I have been charging LiPolys at 3C and greater for over six years and many have over 300 flights on them. Afew had over 500 flights on them before I remioved them from service..

IMO it is much simplier and less expensive to purchase a few good quality LiPolys and charge them at 3C or more than to need to have a dozen or so and only charge at 1C.

It has been proven time and time again that many things do to LiPolys by thier use's are more damanging than charging a greater than 1C.

1C charging was the standard back when the max. dischage rating was 6C ,LiPolys had no balancng leads or connectors, there were no balancing chargers.

http://www.rcgroups.com/forums/showp...61&postcount=1

Charles


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