HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 28, 2012, 12:50 PM
Registered User
flyboy1001e's Avatar
Nelson B.C. Canada
Joined Feb 2003
207 Posts
eflight MV 1s charger

Quote:
Originally Posted by Terry Rigden View Post
You can reduce the charge rate on the charger by opening it up an turning the pots on the PCBs anti clockwise. I did that with mine and it increased the charge time of a 110mAh cell to about an hour so I'm guessing its running at about 100mA but I havent been able to measure it. Anyone out there done the mod and measured the current ?

Terry

I do this to all my 1s chargers
I cut the pot off solder wires to connections on the board and remount in the top half 1/4" hole. I add a book binder sticker for marking current.
I also add a jst connector for parallel charging.

I use the eflight power supply for setting the charge current by connecting four or five discharged cells in parallel as a load. With a amp meter in line I set the max and min and any others I want
I hot glue the pot and jst into place, carefull on the pot too not get glue on the turning part.
I also use a hole punch on the pads to make the screws accessible
Hope this helps.

ps: Charge rates could be a little lower with batteries depending on their state or charge, but you know it won't be higher.

Mike
flyboy1001e is offline Find More Posts by flyboy1001e
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 28, 2012, 01:24 PM
Registered User
3d astronaut's Avatar
United States, MI, Portage
Joined Sep 2011
3,685 Posts
On the topic of chargers.. Is it possible to use a say, 6s 3000mah pack to power a charger like the accucel 6 or a similar charger to charge 1s packs? It seems there has to be a way to use a larger lipo to charge smaller lipos instead of having to haul a power supply around, find an open outlet in an indoor venue etc.
3d astronaut is offline Find More Posts by 3d astronaut
RCG Plus Member
Latest blog entry: Fatshark Attitude 1.3ghz
Reply With Quote
Old Dec 28, 2012, 01:32 PM
Registered User
TurboRacer's Avatar
United States, CT, Waterbury
Joined Oct 2002
1,605 Posts
Yes - but I think you want to use a 3S pack to get the 12v... I could be wrong... 6s is like 22v - I think that will fry the charger..
TurboRacer is offline Find More Posts by TurboRacer
Reply With Quote
Old Dec 28, 2012, 02:05 PM
Gopher huntin' stick jockey
turboparker's Avatar
East Bethel, MN USA
Joined Jul 2009
11,175 Posts
Quote:
Originally Posted by 3d astronaut View Post
On the topic of chargers.. Is it possible to use a say, 6s 3000mah pack to power a charger like the accucel 6 or a similar charger to charge 1s packs? It seems there has to be a way to use a larger lipo to charge smaller lipos instead of having to haul a power supply around, find an open outlet in an indoor venue etc.
It's very common to use a large LiPo for that purpose. As TR noted, you'd want a 3s or 4s pack. The Accucel 6 is designed for 11-17V input, so you'd definitely want to go with a 4s pack to minimize current draw. Just be sure that you set the input voltage cutoff high enough so that you never discharge your source pack deeper than 80% as measured by how many mAh it takes to recharge it. I'd set the input cutoff to 14V initially, and then see how many mAh it takes to recharge it after charging enough of your largest packs to reach the source cutoff.

Keep in mind that the loaded voltage at a particular depth-of-discharge is load-dependent. At low current with respect to continuous discharge C-rating, a 3.8V/cell cutoff can result in a 110% discharge, while at moderate current, a 3.8V/cell cutoff usually results in a 50% discharge. So the source pack's actual discharge depth at a given cutoff voltage will vary, depending upon the source pack's internal resistance and how much current the charger is pulling at the time. Charger current is determined by the voltage of the battery being charged, the programmed charge current, and whether the charger is in the constant-current or constant-voltage segment of the charge cycle. To be sure that you don't kill your source pack by discharging it deeper than 80%, set the input cutoff voltage so that you only use 50% of the source pack's capacity when charging your highest voltage, highest charge packs.

Given that the lowest charge rate is 100mA on the Accucel 6, you'd have to charge a pair of the factory 30 mAh cells in parallel to stay below the 2.5c charge rating. If you want to charge a single factory cell, you'll need a charger that can be set to 75 mA or lower.

Joel
turboparker is online now Find More Posts by turboparker
RCG Plus Member
Last edited by turboparker; Dec 28, 2012 at 03:23 PM. Reason: Added info
Reply With Quote
Old Dec 28, 2012, 02:30 PM
Registered User
flyboy1001e's Avatar
Nelson B.C. Canada
Joined Feb 2003
207 Posts
Quote:
Originally Posted by 3d astronaut View Post
On the topic of chargers.. Is it possible to use a say, 6s 3000mah pack to power a charger like the accucel 6 or a similar charger to charge 1s packs? It seems there has to be a way to use a larger lipo to charge smaller lipos instead of having to haul a power supply around, find an open outlet in an indoor venue etc.
3d

Keep in mind that the charger you use, needs to be able to charge at less than 100ma, if you want to charge a single 30mah cell at 1c

Mike
flyboy1001e is offline Find More Posts by flyboy1001e
Reply With Quote
Old Dec 28, 2012, 03:26 PM
Registered User
3d astronaut's Avatar
United States, MI, Portage
Joined Sep 2011
3,685 Posts
Hey thanks guys. Has anyone actually done this? off to find the biggest 4s lipo I can find flyboy, great idea on that jst plug. I always seem to fly all 3 packs for my mv then realize that I probably should have started charging one a few minutes after it hit lvc.
3d astronaut is offline Find More Posts by 3d astronaut
RCG Plus Member
Latest blog entry: Fatshark Attitude 1.3ghz
Reply With Quote
Old Dec 28, 2012, 04:51 PM
Whatever goes up must go BOOM
joker24458's Avatar
United States, OH, Kent
Joined Mar 2012
1,855 Posts
Wait a minute........this big batt/charger/small batt idea is very appealing to me because I have an Accucel 6. I do not have a 4S pack, as I currently do not have a plane that needs 4S, but I do have 3S packs. But the thing is that I have never found out how to change the charge rate on the charger. How do you do it? On another note, what is the formula to find the charge rate that a battery(ies) charges at?

-joker
joker24458 is offline Find More Posts by joker24458
Reply With Quote
Old Dec 28, 2012, 05:07 PM
Kit Manufacturer
coreman's Avatar
United States, MA, Southbridge
Joined Feb 2010
3,359 Posts
Quote:
Originally Posted by joker24458 View Post
Wait a minute........this big batt/charger/small batt idea is very appealing to me because I have an Accucel 6. I do not have a 4S pack, as I currently do not have a plane that needs 4S, but I do have 3S packs. But the thing is that I have never found out how to change the charge rate on the charger. How do you do it? On another note, what is the formula to find the charge rate that a battery(ies) charges at?

-joker
I almost always charge at 1C because I have time. A fully discharged battery will charge in an hour at 1C. If you have a 1000mah battery, that means a charge rate of 1000ma or 1 amp. A 100mah would be .1 amps (100ma) which is about as low as most chargers can go. So charging a 30mah battery at that rate is 3.33C. As someone mentioned earlier the battery itself says to not charge at higher than 75ma so you really need to charge at least 2 batteries in parallel at .1 amp

And to charge at 2C, you double the capacity of the battery 2C stands for "2 times the Capacity"
coreman is online now Find More Posts by coreman
RCG Plus Member
Latest blog entry: The Gia Normans are coming
Reply With Quote
Old Dec 28, 2012, 05:11 PM
Elfi Flyer
Doug Sipprell's Avatar
Rock Hill, SC
Joined Oct 2002
5,534 Posts
One of the reasons I like my EFT 4-Play chargers is that I can set the charge rates, per battery (up to four individual charge ports) at what charge rate I might need for a single cell Lipo. In the photos, you can see a 30mAh stock EF Lipo for the MV being charged at a rate of 50mAh, which is well within the 2.5C rating. I could also go conservative and charge it at 30mAh, setting the DIP switches to 10 + 20, for a total of 30mAh charge rate. I use a 3S 2200 Lipo to power the charging device. This set up, in most of my Micro fleet's "hangars", has provided mobility and proper charging of 1S Lipos ranging from 30 - 280mAh ratings. Nice way also to put "older 3S Lipo's" back in service. FWIW

RD
Doug Sipprell is offline Find More Posts by Doug Sipprell
RCG Plus Member
Last edited by Doug Sipprell; Dec 28, 2012 at 10:27 PM.
Reply With Quote
Old Dec 28, 2012, 05:30 PM
Whatever goes up must go BOOM
joker24458's Avatar
United States, OH, Kent
Joined Mar 2012
1,855 Posts
Ok, so would this setup work?

Accucel 6 powered by a 3S 2200mah pack charging two or more 1S 30mah batteries.

-joker
joker24458 is offline Find More Posts by joker24458
Last edited by joker24458; Dec 28, 2012 at 08:40 PM.
Reply With Quote
Old Dec 28, 2012, 05:54 PM
Registered User
3d astronaut's Avatar
United States, MI, Portage
Joined Sep 2011
3,685 Posts
Quote:
Originally Posted by Doug Sipprell View Post
One of the reasons I like my ETF 4-Play chargers is that I can set the charge rates, per battery (up to four individual charge ports) at what charge rate I might need for a single cell Lipo. In the photos, you can see a 30mAh stock EF Lipo for the MV being charged at a rate of 50mAh, which is well within the 2.5C rating. I could also go conservative and charge it at 30mAh, setting the DIP switches to 10 + 20, for a total of 30mAh charge rate. I use a 3S 2200 Lipo to power the charging device. This set up, in most of my Micro fleet's "hangars", has provided mobility and proper charging of 1S Lipos ranging from 30 - 280mAh ratings. Nice way also to put "older 3S Lipo's" back in service. FWIW

RD
where do you get that charger?
3d astronaut is offline Find More Posts by 3d astronaut
RCG Plus Member
Latest blog entry: Fatshark Attitude 1.3ghz
Reply With Quote
Old Dec 28, 2012, 06:16 PM
Registered User
Bill Glover's Avatar
United Kingdom, Bracknell
Joined Nov 2000
11,019 Posts
Quote:
Originally Posted by coreman View Post
A fully discharged battery will charge in an hour at 1C
No it won't, because when the cell voltage reaches 4.2V Lipo charging switches from constant current mode (the rate you have set) to constant voltage mode (at a lower and steadily reducing current). So it takes more than an hour to give a full charge at 1C.
Bill Glover is offline Find More Posts by Bill Glover
Reply With Quote
Old Dec 28, 2012, 07:08 PM
Kit Manufacturer
coreman's Avatar
United States, MA, Southbridge
Joined Feb 2010
3,359 Posts
Quote:
Originally Posted by Bill Glover View Post
No it won't, because when the cell voltage reaches 4.2V Lipo charging switches from constant current mode (the rate you have set) to constant voltage mode (at a lower and steadily reducing current). So it takes more than an hour to give a full charge at 1C.
Correct, but this compensates for the fact that the battery is never totally depleted to start with. It was an example to show the rating of the battery (30mah) as being a charge rate of 30ma for 1 hour, 30mah without getting too distracted with the actual constant current/voltage functionality of a modern LiPo charger. There are always losses in the process
coreman is online now Find More Posts by coreman
RCG Plus Member
Latest blog entry: The Gia Normans are coming
Reply With Quote
Old Dec 28, 2012, 08:40 PM
Whatever goes up must go BOOM
joker24458's Avatar
United States, OH, Kent
Joined Mar 2012
1,855 Posts
Quote:
Originally Posted by joker24458 View Post
Ok, so would this setup work?

Accucel 6 powered by a 3S 2200mah pack charging two or more 1S 30mah batteries.

-joker
REPOST

-joker
joker24458 is offline Find More Posts by joker24458
Reply With Quote
Old Dec 28, 2012, 10:12 PM
Registered User
I R Irv's Avatar
United States, IL, Washington
Joined Nov 2008
1,921 Posts
Quote:
Originally Posted by 3d astronaut View Post
where do you get that charger?
Post# 605
I R Irv is online now Find More Posts by I R Irv
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Wanted I Need a Parkzone (Vapor) DSM2 Rec/ESC/servo "Brick" *** Joe Pierson Aircraft - Electric - Micro & Indoor Airplanes (FS/W) 2 Mar 25, 2012 10:27 PM
Sold parkzone vapor bnf original $50.00 shipped chrisb22 Aircraft - Electric - Micro & Indoor Airplanes (FS/W) 3 Mar 03, 2012 01:25 PM