HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 04, 2014, 10:19 PM
Registered User
SubaruMike's Avatar
United States, DE, Magnolia
Joined Nov 2011
400 Posts
Discussion
A little input in regards to my new lipo please!

Hello everyone! I just purchases a new 6s 3000mah lipo a week ago. I have three cycles on it and I want to make sure that the balance-charge time is normal is the cells are balancing properly.

Post flight:

3.77 3.76 3.76
3.76 3.76 3.77


After charge:

4.19 4.20 4.20
4.19 4.19 4.20


The charge time (charging at 3.0 amps) : 115 minutes.

Is this balance-charge time normal for a 6s 3000mah? If you need anymore information, please let me know. I'm new(ish) to electrics and certainly no expert in it
SubaruMike is offline Find More Posts by SubaruMike
RCG Plus Member
Reply With Quote
Sign up now
to remove ads between posts
Old May 04, 2014, 10:46 PM
Frankenstein recycled packs
rampman's Avatar
USA, AZ, Gilbert
Joined Jan 2006
8,805 Posts
Depends on charger and its settings.
Pre and post voltages look ok so my guess is you have a low end charger.

Rick
rampman is offline Find More Posts by rampman
Reply With Quote
Old May 05, 2014, 02:09 AM
Registered User
Letchworth, Great Britain (UK)
Joined Jul 2004
11,700 Posts
In theory, if you charge a battery at 1C rate it should take about 1 hour if it was only about 20% full when the charge started. For a 3000mAh battery, 1C equates to 3A charge rate.

The fact that your pack is taking twice as long suggests that either the charger is unable to achieve a 3A charge rate with a 6S pack (that's 80 watts or so) because it's too small, or the battery is poor quality, and the balancing part of the charge cycle is taking far too long.

What charger have you got? Does it have a display that shows you how many amps it's actually putting into the battery? If it does, and you watch it, you should see it maintaining the full amp rate until the battery reaches 4.2v per cell, at which point it will gradually reduce the amps while maintaining the battery at 4.2v per cell. These two phases of the charge are referred to as the CC (constant current) and CV (constant voltage) phases, and the CV phase can take a while with a poor battery.

What brand pack are you charging? Is it new, or did you buy it used?
abenn is online now Find More Posts by abenn
Reply With Quote
Old May 05, 2014, 02:34 AM
Good Ole American Bad Az 4real
tntpoof's Avatar
Joined Aug 2012
480 Posts
That is a normal charge time for a 6 cell lipo with a 3 amp charger.. you can also use charger without balance setup your charge time will be less.. Im guessing its a 50 watt charger..so all is good I read ur post unlike others who ask Q's u have answered in 1st post..
so what charger ?
tntpoof is offline Find More Posts by tntpoof
Reply With Quote
Old May 05, 2014, 08:40 AM
Registered User
SubaruMike's Avatar
United States, DE, Magnolia
Joined Nov 2011
400 Posts
Thank you for your responses everyone!

Charger: Thunder T6 Multi. I am not sure of the wattage of it.

Battery: Brand new from the factory Haiyin
SubaruMike is offline Find More Posts by SubaruMike
RCG Plus Member
Reply With Quote
Old May 05, 2014, 01:21 PM
Registered User
Letchworth, Great Britain (UK)
Joined Jul 2004
11,700 Posts
Quote:
Originally Posted by tntpoof View Post
That is a normal charge time for a 6 cell lipo with a 3 amp charger.. ...
I disagree If the charger can output 3 amps, then the charge time for a 3000mAh battery should normally be around 1 hour, not close-on 2 hours.

Trouble is, the OP's charger is rated for 50 watts, so with a 6S LiPo that means it can only deliver less than 2 amps, even if the charge setting is set for 3 amps. That explains the extended charge time, but not the slight imbalance between cells.
abenn is online now Find More Posts by abenn
Reply With Quote
Old May 05, 2014, 01:32 PM
Registered User
SubaruMike's Avatar
United States, DE, Magnolia
Joined Nov 2011
400 Posts
Can anyone suggest an affordable charger that is up to the task? Also, what specs should I be looking at?
SubaruMike is offline Find More Posts by SubaruMike
RCG Plus Member
Reply With Quote
Old May 05, 2014, 02:26 PM
Good Ole American Bad Az 4real
tntpoof's Avatar
Joined Aug 2012
480 Posts
Its a new lipo and his charger will not charge at 3 amps on a 6 cell battery so it is NORMAL for that charger as 4 slight cell outa balance New battery ..

You would like a charger that can handle 28vdc input..
tntpoof is offline Find More Posts by tntpoof
Reply With Quote
Old May 05, 2014, 02:29 PM
Good Ole American Bad Az 4real
tntpoof's Avatar
Joined Aug 2012
480 Posts
Quote:
Originally Posted by abenn View Post
I disagree If the charger can output 3 amps, then the charge time for a 3000mAh battery should normally be around 1 hour, not close-on 2 hours.

Trouble is, the OP's charger is rated for 50 watts, so with a 6S LiPo that means it can only deliver less than 2 amps, even if the charge setting is set for 3 amps. That explains the extended charge time, but not the slight imbalance between cells.
_pure 100% counter-diction ..oh his charger explains the extended charge time LOL
tntpoof is offline Find More Posts by tntpoof
Reply With Quote
Old May 05, 2014, 04:12 PM
Registered User
ggcrandall1's Avatar
USA, GA, Marietta
Joined Aug 2005
5,696 Posts
SubaruMike,

Pease read this: http://www.tjinguytech.com/charging-how-tos
Also check the specs on your charger.

Knowing the specs on your charger and the charging requirements of your battery would have answered your original question.

Glen
ggcrandall1 is online now Find More Posts by ggcrandall1
Reply With Quote
Old May 05, 2014, 05:11 PM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
21,006 Posts
Quote:
Trouble is, the OP's charger is rated for 50 watts, so with a 6S LiPo that means it can only deliver less than 2 amps, even if the charge setting is set for 3 amps. That explains the extended charge time, but not the slight imbalance between cells.
Right on abenn.
And Mike, with hobby grade electronics, a 0.01V difference would be meaningless.
hoppy is offline Find More Posts by hoppy
Last edited by hoppy; May 05, 2014 at 05:19 PM.
Reply With Quote
Old May 05, 2014, 05:49 PM
Registered User
SubaruMike's Avatar
United States, DE, Magnolia
Joined Nov 2011
400 Posts
So why exactly is my charger not charging at 3 amps? I will need to upgrade my charger and power supply? I'm sorry for the ignorance, but anything electric is over my head.
SubaruMike is offline Find More Posts by SubaruMike
RCG Plus Member
Reply With Quote
Old May 05, 2014, 07:13 PM
Registered User
ggcrandall1's Avatar
USA, GA, Marietta
Joined Aug 2005
5,696 Posts
Quote:
Originally Posted by SubaruMike View Post
So why exactly is my charger not charging at 3 amps? I will need to upgrade my charger and power supply? I'm sorry for the ignorance, but anything electric is over my head.
It's a matter of maximum power. Your charger has a 50 watt limit. The battery to be charged a 3 amps requires 75 watts. (25.2V * 3A = 75.6W)When he charger reached 50 watts it had to reduce the current to keep from destroying itself.

Here are the specs on your charger:

Specification:
Operating voltage range: DC 11~15V
Power source: 12V DC (car battery) / AC mains PSU (>200Watts)
Charge power: 50watts, current is regulated accordingly
e.g. 11.1V battery, charge current approx. 4.5A
e.g. 22.2V (6s) battery, charge current approx. 2.2A
Discharge power: 5 Watts, current is regulated accordingly
Cell count : 1-15 Ni-xx / 1-6 Li-xx / 1-10 Lead acid cells (2~20V)
Current drain for balancing li-xx: 300mA
Charge termination Ni-xx: Automatic, negative Delta Peak method
Charge termination Lead acid & Li-xx: Automatic, voltage dependent, CC-CV process
Dimensions: 225.4x158.6x62.4mm
Net weight: 1.09kg

To be able to charge at the full 3 amps you will need a charger capable of at least 75 watts.

Glen
ggcrandall1 is online now Find More Posts by ggcrandall1
Reply With Quote
Old May 06, 2014, 02:26 AM
Registered User
Letchworth, Great Britain (UK)
Joined Jul 2004
11,700 Posts
Quote:
Originally Posted by SubaruMike View Post
So why exactly is my charger not charging at 3 amps? I will need to upgrade my charger and power supply? I'm sorry for the ignorance, but anything electric is over my head.
Quite simply, watts = amps x volts

So, a 50 watt charger might be able to do 3 amps with a 3S battery (3 amps x 12.6 volts = 37.8 watts), but when you give it a 6S battery it can't do it because of its watts limit (3 amps x 25.2 volts = 75.6 watts = too much for the charger), so it keeps the amps down to whatever gives 50 watts.

Note that I've used the battery's fully-charged voltage of 4.2v per cell, instead of 3.7v per cell used in the manufacturer's spec.
abenn is online now Find More Posts by abenn
Reply With Quote
Old May 06, 2014, 02:28 PM
BGR
Foam Junkie
United States, CA, Oceanside
Joined Dec 2003
1,656 Posts
The charger is limited but it chargers the battery though rather slowly. The slow charge is great for the battery but no great if your in a hurry.

A middle of the road 250 watt charger and power supply is around $125.
BGR is offline Find More Posts by BGR
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Little play in my motor shaft ? Shung Electric Warbirds 7 Mar 28, 2014 07:42 PM
Discussion Lipo alarm a little too much for my tastes! chrisely24 Multirotor Electronics 4 Feb 17, 2014 11:58 PM
For Sale New Celectra 1S DC 6V input variable rate LiPO charger $15 shipped Tomy. Aircraft - Electric - Batteries & Chargers (FS/W) 1 Feb 17, 2014 10:32 PM
Sold Vintage Midwest Das Little Stick Kit New in the Box hobbyfun100 Aircraft - Fuel - Airplanes (FS/W) 1 Oct 29, 2013 05:40 PM
Sold Vintage Midwest Das Little Stick Kit New in the Box hobbyfun100 Aircraft - Electric - Airplanes (FS/W) 3 Oct 29, 2013 05:39 PM