HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 28, 2012, 11:50 PM
Registered User
octanejunkie's Avatar
United States, CA, Santa Monica
Joined Dec 2011
135 Posts
Discussion
Balance charging 6 1S lipo batteries at once

So I just got my Thunder AC6 charger and want to charge mutliple 1S lipos simultaneously, but I want to charge using the balancer as not to have to worry about the state of each cell...

Does anyone know if a cable like this exists, or if I have to make one what the pinout is? I know there is one for mCP X batteries, but I have not seen one for the little ones used for the mSR X.

I am assuming that the XH Adapter (in pic below charger) that came with the charger has a 6S connector with 7 pins: far left black cable is neg and each of the other 6 are for each individual cell of a 6S battery.

If I am to make an multi pigtail cable then neg is common to all leads and pos goes to each one of the other 6 pins in the 7-pin connector?
octanejunkie is offline Find More Posts by octanejunkie
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 29, 2012, 03:24 AM
Registered User
Letchworth, Great Britain (UK)
Joined Jul 2004
11,892 Posts
1S packs don't need balancing because there's no other cell to balance them against

1S packs are most commonly charged in parallel. Connecting them in parallel ensures that each pack is at exactly the same voltage as all its neighbours. You then set the charger for 1S, and set the amps for X times the amps you would use for a single pack, where X is the number of packs you're charging.

You could, if you want, charge them in series, using the charger's balancing function to keep each cell in step. To do this you'd have to get, or more likely build, a harness that connects the packs in a chain -- pin 1 would be + of the first pack, pin 2 would be - of the first pack and + of the second pack, pin 3 would be - of the second pack and + of the third pack, and so on. So you'd end up with a balance plug that has one more pin than the number of packs. One problem with this approach is you may not be able to use a 6S plug, for example, if you've only got four packs ready to charge, so you may have to make a different harness for every different cell-count. Series charging is generally not recommended with multi-cell packs, but I don't see why it shouldn't be okay for single cells with similar characteristics, provided you're using the balancer and not the charger's main charge leads.

With parallel charging, you simply plug in however many packs are ready for charging -- it doesn't matter if there's a few unused slots in the parallel board/harness.
abenn is offline Find More Posts by abenn
Reply With Quote
Old Feb 29, 2012, 02:55 PM
CP heli ≠ 3D heli
Gedexas's Avatar
United States, NJ, Point Pleasant Beach
Joined Mar 2009
1,676 Posts
When charging in series, you'd have to connect all 6 packs or otherwise the circuit will not be complete. You could build a harness with a switch to select how many packs you are charging, but that would make one clumsy harness.
Gedexas is offline Find More Posts by Gedexas
Reply With Quote
Old Feb 29, 2012, 11:31 PM
Registered User
octanejunkie's Avatar
United States, CA, Santa Monica
Joined Dec 2011
135 Posts
Quote:
Originally Posted by abenn View Post
1S packs don't need balancing because there's no other cell to balance them against
For sure, that's not news to me

Quote:
Originally Posted by abenn View Post
1S packs are most commonly charged in parallel. Connecting them in parallel ensures that each pack is at exactly the same voltage as all its neighbours. You then set the charger for 1S, and set the amps for X times the amps you would use for a single pack, where X is the number of packs you're charging.
Yea I'm too lazy for that, it requires math and stuff, I'm looking to use the technology in the AC6 charger and charge in series - thanks for a well written reply abenn

Quote:
Originally Posted by Gedexas View Post
When charging in series, you'd have to connect all 6 packs or otherwise the circuit will not be complete. You could build a harness with a switch to select how many packs you are charging, but that would make one clumsy harness.
Probably going to build a harness to charge 2 or 3 batteries at once, though the idea of topping off 6 batteries at once might have me build more than one harness...
octanejunkie is offline Find More Posts by octanejunkie
Reply With Quote
Old Feb 29, 2012, 11:43 PM
CP heli ≠ 3D heli
Gedexas's Avatar
United States, NJ, Point Pleasant Beach
Joined Mar 2009
1,676 Posts
Quote:
Originally Posted by octanejunkie View Post
Probably going to build a harness to charge 2 or 3 batteries at once, though the idea of topping off 6 batteries at once might have me build more than one harness...
I'm making one right now for my mCPx batteries that can handle six batteries, but has a selector switch for 2,3,4,5 and 6. I found a need for such a harness, because I have already made one that can do six, but I have nine 300mAh batteries and two 250mAh, so instead of having separate cables for charging all these cells, I'm making one that can be universal. This way I can charge all my batteries in a rotation while flying non-stop.
Gedexas is offline Find More Posts by Gedexas
Reply With Quote
Old Feb 29, 2012, 11:51 PM
Registered User
octanejunkie's Avatar
United States, CA, Santa Monica
Joined Dec 2011
135 Posts
Quote:
Originally Posted by Gedexas View Post
I'm making one right now for my mCPx batteries that can handle six batteries, but has a selector switch for 2,3,4,5 and 6. I found a need for such a harness, because I have already made one that can do six, but I have nine 300mAh batteries and two 250mAh, so instead of having separate cables for charging all these cells, I'm making one that can be universal. This way I can charge all my batteries in a rotation while flying non-stop.
Next heli I am doing it right : buy 10 of the same batteries at once, number them then fly and charge in series just like you suggest

I'd like to see a pic and schematic of your switched harness if you wouldn't mind, I like options and projects

FWIW, a parallel version of the 6x mCP X harness already exists and might be a cheap donor for connectors...
octanejunkie is offline Find More Posts by octanejunkie
Reply With Quote
Old Mar 01, 2012, 12:00 AM
CP heli ≠ 3D heli
Gedexas's Avatar
United States, NJ, Point Pleasant Beach
Joined Mar 2009
1,676 Posts
Quote:
Originally Posted by octanejunkie View Post
Next heli I am doing it right : buy 10 of the same batteries at once, number them then fly and charge in series just like you suggest

I'd like to see a pic and schematic of your switched harness if you wouldn't mind, I like options and projects

FWIW, a parallel version of the 6x mCP X harness already exists and might be a cheap donor for connectors...
Two six cell parallel cables are what I dissected to make mine.

Here's the only difference between the regular series cable and the switchable one: I'm planning to use a switch like this and put it between the positive cable [where banana plugs connect] and each balance connector wire. I'm also thinking to substitute the switch with leftover 3mm banana plugs I have leftover from previous motor/ESC setups.
Gedexas is offline Find More Posts by Gedexas
Reply With Quote
Old Mar 01, 2012, 12:13 AM
CP heli ≠ 3D heli
Gedexas's Avatar
United States, NJ, Point Pleasant Beach
Joined Mar 2009
1,676 Posts
Below I attached the wiring diagram for the plugs I'm making. The selectable cable design is not final, I may replace the switch with banana plugs. I also have standardized everything to deans plugs, but that's obviously not a requirement.
Gedexas is offline Find More Posts by Gedexas
Reply With Quote
Old Mar 01, 2012, 12:31 AM
Registered User
octanejunkie's Avatar
United States, CA, Santa Monica
Joined Dec 2011
135 Posts
Quote:
Originally Posted by Gedexas View Post
Below I attached the wiring diagram for the plugs I'm making. The selectable cable design is not final, I may replace the switch with banana plugs. I also have standardized everything to deans plugs, but that's obviously not a requirement.
Cool, make me one with mSR X plugs and I'll be your pal forever

Seriously though, thanks for posting that; can't wait to hear how happy you are with the final product

BTW - late for you now isn't it?
octanejunkie is offline Find More Posts by octanejunkie
Reply With Quote
Old Mar 07, 2012, 10:35 AM
Registered User
octanejunkie's Avatar
United States, CA, Santa Monica
Joined Dec 2011
135 Posts
Serial "balancing" adapter = done!

So following the diagram provided by Gedexas sans selector, along with the pinout in my AC6 manual, and some polarity testing, I have created a 3 x JST balanced adapter.

Here is a pic



I set my charger to 3S, 11.1v as follows



I connected 3 x 1S 3.7v 500mAh 12C batteries and started charging after having flown to LVC, as you can see all cells were slightly different voltages

Apparently the AC6 is smart enough to adjust each individual cell in the series, without using the Balance charge feature...


I monitored progress and kept an eye on both battery temperatures and voltage and in about 20 mins at 0.3A rate, all 3 cells evened out and the charger stopped



I then measured each battery individually with my standalone 8S voltage meter and found the cells to be around 4.18v which I think is acceptable.

After about 15 mins I set the charger to storage mode and ran the 3 batteries down to store


Only things I wish I knew
1) how to change the voltage settings on the AC6 charger, only allows me to select cell count, not set target voltages
-like it wants to store to 3.80v and I want to set to 3.85v
2) why the AC6 and my standalone volt meter disagree with each other
-I can understand and accept a 0.01+/- variation but it is more like 0.03 off

Next I will experiment with parallel charging and will just order the 6 x JST and 6 x pico cables from hobbyking.com
octanejunkie is offline Find More Posts by octanejunkie
Reply With Quote
Old Mar 07, 2012, 02:31 PM
aka: A.Roger Wilfong
gnofliwr's Avatar
Novi, Michigan, United States
Joined Jan 2001
2,543 Posts
Seems like a lot of work to avoid going 3, 6, 9, ... to figure the charge current. But if you're going to use a DIP slide switch (or any other single pole, multi-position switch), make sure it is "break before make". Otherwise, you'll need to make sure you set it before plugging in the cells and that you don't have it set half way between two positions.

It it's "make before break", the slider will make contact with two cells at the same time and it's going to short out a cell. The short, even briefly, won't do the cell any good; and the spark might weld the slider in place, ruining the switch and putting a short across the cell until you unplug it from the harness.

- Roger
gnofliwr is online now Find More Posts by gnofliwr
Reply With Quote
Old Mar 07, 2012, 03:37 PM
CP heli ≠ 3D heli
Gedexas's Avatar
United States, NJ, Point Pleasant Beach
Joined Mar 2009
1,676 Posts
Quote:
Originally Posted by gnofliwr View Post
Seems like a lot of work to avoid going 3, 6, 9, ... to figure the charge current. But if you're going to use a DIP slide switch (or any other single pole, multi-position switch), make sure it is "break before make". Otherwise, you'll need to make sure you set it before plugging in the cells and that you don't have it set half way between two positions.

It it's "make before break", the slider will make contact with two cells at the same time and it's going to short out a cell. The short, even briefly, won't do the cell any good; and the spark might weld the slider in place, ruining the switch and putting a short across the cell until you unplug it from the harness.

- Roger
I thought of that, so I went with leftover banana plugs instead of the slider switch.
Gedexas is offline Find More Posts by Gedexas
Reply With Quote
Old Jan 01, 2013, 01:56 PM
Registered User
Joined Dec 2012
4 Posts
I hope it's okay to add to a 9 month old thread.

So if I charge 4 150/160 packs at the 1c rate, then I choose 1s, set .15 x 4 for .64?

Some use a 2c rate so that would be .3 x 4 for 1.2?

Am I understanding it.
MLFLY is offline Find More Posts by MLFLY
Reply With Quote
Old Jan 01, 2013, 02:33 PM
Registered User
So. Cal.
Joined Oct 2004
8,374 Posts
You got it!!

Mark
mrforsyth is online now Find More Posts by mrforsyth
RCG Plus Member
Reply With Quote
Old Jan 01, 2013, 02:51 PM
Registered User
Letchworth, Great Britain (UK)
Joined Jul 2004
11,892 Posts
... except that .15 x 4 = .60, not .64

Happy New Year
abenn is offline Find More Posts by abenn
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
For Sale NIB Paraboard for Parallel Charging up to 6 Lipo batteries RC Accessory Aircraft - Electric - Batteries & Chargers (FS/W) 8 Apr 27, 2012 09:09 PM
Sold parallel charge and balance cables for charging up to 6 lipos at once ff954 Aircraft - Electric - Batteries & Chargers (FS/W) 1 Sep 27, 2010 12:09 PM
For Sale Ultra Micro Lipo Charging Harness, Charge 5 batteries at once. bpink43 Aircraft - General - Miscellaneous (FS/W) 1 May 30, 2010 12:08 AM
For Sale Ultra Micro Lipo charging harness, charge 5 batteries at once bpink43 Aircraft - Electric - Helis (FS/W) 0 May 19, 2010 11:55 PM
Help! Balance Charging Two LiPo Batteries at the Same Time with One Charger and Balancer write2dgray Batteries and Chargers 18 Aug 22, 2007 02:20 PM