HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 16, 2010, 05:25 AM
Registered User
ggcrandall1's Avatar
USA, GA, Marietta
Joined Aug 2005
5,892 Posts
Quote:
Originally Posted by ScotY View Post
Ah, okay...I think I understand now! For the CellPro Multi-4, you charge through balance type wiring only, i.e. there are no straight positive/negative leads for charging. To charge a non-FMA pack, you need an adapter just like you'd need for adapting, say, a TP pack to an Align charger, and you'll be balance charging. To charge unbalanced (the equivalent of connecting straight to plus/minus charger outputs), you need an adapter to go from FMA balance connectors to various non-FMA connectors. Is this correct?

Yes. I think you've got it.

If so, I guess that answers my questions and the PL8 can do this type of charging utilizing only it's balance port wiring (current limited, of course).

The PL8 can charge two ways. It can use both the balance taps and main discharge leads which allow charging at the highest possible rate. Or it can charge through the balance taps only which limits the charge rate to 3 amps maximum.

FMA, as long as I can recall, has always done things a little differently from everyone else. I guess that's why it wasn't apparent to me after skimming through the manual and various reviews.

Yes FMA is a bit different but then Thunder Power is different and PolyQuest is different and Align is different. There is not standard for balance tap wiring. It's something we just have to live with.

Thanks, Scot
I hope I have answered your questions. If you have more don't hesitate to ask. Someone on the beta test team will have an answer.

Glen
ggcrandall1 is offline Find More Posts by ggcrandall1
Reply With Quote
Sign up now
to remove ads between posts
Old Feb 16, 2010, 01:19 PM
3DHS 'native'
going4speed's Avatar
USA, TX, Spring
Joined Jan 2008
5,929 Posts
Well for me I have only known charging through the balance leads and that is why I never thought about all the charge current going through the main leads. Thanks for the clarification as I had no idea it would only be pulling low current through the balance taps.

I wonder do you still get a good enough 'feel' for balancing a pack with only discharge through the discharge leads?

It would seem the charger would have a better idea of what was going to the battery if it only charges through the balance taps instead of expecting all the cells in a battery to respond the same to the inbound current.

Quote:
Originally Posted by jfetter View Post
Agreed!!! You folks that want to charge through the balancing leads get over it, the balancing leads have a specific purpose and charging isn't it. You have one extra connection to make, is it really that much easier anyway?

Jack
going4speed is offline Find More Posts by going4speed
Reply With Quote
Old Feb 16, 2010, 03:06 PM
Registered User
ggcrandall1's Avatar
USA, GA, Marietta
Joined Aug 2005
5,892 Posts
Quote:
Originally Posted by going4speed View Post
Well for me I have only known charging through the balance leads and that is why I never thought about all the charge current going through the main leads. Thanks for the clarification as I had no idea it would only be pulling low current through the balance taps.

I wonder do you still get a good enough 'feel' for balancing a pack with only discharge through the discharge leads?

It would seem the charger would have a better idea of what was going to the battery if it only charges through the balance taps instead of expecting all the cells in a battery to respond the same to the inbound current.
Regardless of which method is used for charging (balance taps only or both) the charger is monitoring each cell. Therefore the charger can adjust the charging current to prevent over or under charge for each cell.

Glen
ggcrandall1 is offline Find More Posts by ggcrandall1
Reply With Quote
Old Feb 16, 2010, 09:03 PM
Registered User
Seattle
Joined Sep 2007
2,246 Posts
Quote:
Originally Posted by going4speed View Post
Well for me I have only known charging through the balance leads and that is why I never thought about all the charge current going through the main leads.

I wonder do you still get a good enough 'feel' for balancing a pack with only discharge through the discharge leads?

It would seem the charger would have a better idea of what was going to the battery if it only charges through the balance taps instead of expecting all the cells in a battery to respond the same to the inbound current.
This confusion may have its roots in FMA marketing such as this;

Quote:
FMA’s Cellpro Node Connector is a key part of the system. It enables the charger to monitor individual cells and independently charge each cell to its optimum level.
The method used by other manufactures was to charge with the discharge leads, then use a balancer attached to the node connectors to "bleed off" current from the higher cells until the lower cells catch up. The FMA method didn't require any wasteful bleed off of current and was said to be faster since the balancing started earlier on during the charge cycle. It was later discovered (by someone who claimed it have Cellpro 4s schematic) that the Cellpro 4s was charging through the two outside leads and bleeding of current just like the other brands. I'm not sure if there is any truth to that.

Regardless of what method is being used, its important not to exceed the max current of the node wires, and that the charger is connected to each cell for balancing and monitoring, leaving asside the parallel charging discussion for simplicity. Attaching the node wires is required. Attaching the discharge leads is optional as long as you don't exceed about 3.5 amps.
Gregor99 is offline Find More Posts by Gregor99
Reply With Quote
Old Feb 16, 2010, 10:16 PM
Registered User
ScotY's Avatar
Joined Feb 2001
2,818 Posts
Thanks, Glen...all my questions have been answered. Appreciate it! Now the only big challenge in my mind is finding a power supply that's plug and play and costs less than the darned charger! I assume that's not possible at this time. I'm no electronics person and don't like dealing with anything that's 110v.
ScotY is offline Find More Posts by ScotY
Reply With Quote
Old Feb 16, 2010, 10:20 PM
Registered User
ScotY's Avatar
Joined Feb 2001
2,818 Posts
Gregor99,

Yes, I noticed that yesterday when I was reading the Cellpro 4 manual...it is a bit confusing and lead me to believe incorrectly that it could only charge FMA batteries. They should rewrite that so as not to drive away potential customers.

Okay, now you've got me wondering about the Cellpro 4, and the PL8 now. How do the chargers charge each cell individually? Wouldn't it be the equivalent of having 4 channels, i.e. four chargers integrated into a single case for the Cellpro 4 and 8 channels for the PL8?
ScotY is offline Find More Posts by ScotY
Reply With Quote
Old Feb 16, 2010, 10:49 PM
Registered User
Seattle
Joined Sep 2007
2,246 Posts
Quote:
Originally Posted by ScotY View Post
Gregor99,

Okay, now you've got me wondering about the Cellpro 4, and the PL8 now. How do the chargers charge each cell individually? Wouldn't it be the equivalent of having 4 channels, i.e. four chargers integrated into a single case for the Cellpro 4 and 8 channels for the PL8?
I don't make the news, I just report it

http://www.rcgroups.com/forums/showp...&postcount=325
Gregor99 is offline Find More Posts by Gregor99
Reply With Quote
Old Feb 17, 2010, 01:38 AM
Registered User
Melbourne, Australia
Joined May 2006
6,407 Posts
They don't, they charge via the overall pos/neg and balance via the intermediate nodes.
kgfly is offline Find More Posts by kgfly
Reply With Quote
Old Feb 17, 2010, 03:31 AM
Registered User
SteveM732's Avatar
United States, OR, Beaverton
Joined Feb 2008
1,976 Posts
I have looked at the balance current flow in a 3S charger that was made up of a single cell ICs to individually charge each cell. The only difference is that instead of current only traveling out of a balance wire it can also flow into the battery cell via the balance wire.

Now if you have an ideal battery in perfect balance there will be no current flow in or out of the balance wires regardless of the balancing method used. The danger with being able to inject current via the balance taps is that you now have extra current flowing into a cell that could be significant compared to your charge current, resulting in one or more cells being charged at a higher than desired rate. With the method used by FMA (and pretty much all other chargers) you'll know that no cell will ever get more than the target charge rate.
SteveM732 is offline Find More Posts by SteveM732
Reply With Quote
Old Feb 17, 2010, 12:30 PM
CPII HD & PL8 beta tester
Jack Doherty's Avatar
Aubrey, Texas
Joined May 2009
92 Posts
PL8 Balancing

The screen shot below shows an out of balance 6s 3000mAh battery pack and how the PL8 handles it. The PL8 can be set to balance charge two ways 1) Digital ON/Off or 2) 32 step Proportional (the default).

Note in this battery pack that cell #4 is low at start of charge and cell #6 is even lower. As the battery is charging the higher voltage cells are being Bypassed at up to 50%. Cell #4 is catching up and is being Bypassed 9%, while cell #6 is receiving a full current.

After charging less than three minutes cell #4 is almost balanced. The current to it is now only decreased by 9%. Remember 32 step proportional not just On/Off.

At the end of 4 minutes all 6 cells are in balance.

Hope this helps illustrate how the PL8 balances a pack.

Jack
Jack Doherty is offline Find More Posts by Jack Doherty
Reply With Quote
Old Feb 20, 2010, 12:53 AM
Registered User
Himalaya's Avatar
Joined May 2009
510 Posts
Thanks Jack, very clear explaination. The variable balancing rate is a great advantage over other chargers.
Himalaya is offline Find More Posts by Himalaya
Reply With Quote
Old Feb 21, 2010, 03:29 PM
Registered User
Joined Aug 2008
14 Posts
Tim Marks,

Is there any news on the "smart parallel adapter" or equivalent by chance?

I've purchased FMA products in the past and love them but my buying decision for this charger will be based on the ability to charge multiple batteries, hopefully 4 or possibly more.

I'm hoping you will have details soon as I would like to make a decision on a new charger before the end of FMA's introductory price.

Thank you,

CMorgan
Cptmorgan is offline Find More Posts by Cptmorgan
Reply With Quote
Old Feb 22, 2010, 08:51 AM
Registered User
FliteMetal's Avatar
Joined Mar 2009
416 Posts
Parallel Adapter Availability?

Quote:
Originally Posted by Cptmorgan View Post
Tim Marks, Is there any news on the "smart parallel adapter" or equivalent by chance? I've purchased FMA products in the past and love them but my buying decision for this charger will be based on the ability to charge multiple batteries, hopefully 4 or possibly more. I'm hoping you will have details soon as I would like to make a decision on a new charger before the end of FMA's introductory price. Thank you, CMorgan
Ditto the above! I need to charge multiple 12S 7400's for a twin project and see your smart parallel as the practical path. I too want to take advantage of your pre-release pricing on two and in all probability four 8's considering I have a partner in this crime who will need a pair.

Tim, for some reason, inquiries to your email address go unanswered. I did consult with George M. who agrees with my assessment of the 8's for my B-47's needs. Would be good to receive a reply to my inquiries.
FliteMetal is offline Find More Posts by FliteMetal
Reply With Quote
Old Feb 22, 2010, 10:46 AM
Registered User
Efloatflyer's Avatar
Winston-Salem, North Carolina
Joined May 2003
225 Posts
I really like the battery clamps (Alligator clamps) that come with this charger.
Can a pair be purchased from FMA? I would like to use these in a project ...
I have never seen them before anywhere... if not then perhaps a link to a supplier.
Efloatflyer is offline Find More Posts by Efloatflyer
Reply With Quote
Old Feb 22, 2010, 11:29 AM
Mis-guided heli guy
Jeff_edge540's Avatar
Austin, TX USA
Joined Mar 2007
1,470 Posts
Anyone know where we can find a 1000w 24v AC/DC power supply?
Jeff_edge540 is offline Find More Posts by Jeff_edge540
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Sneak Peek! 2, 1:8 scale scratchbuilts ooby Scale Boats 32 Sep 17, 2014 04:09 PM
Discussion Proposed schemes for 2010 season RAF BAe Hawk display-sneak peek! Matt Halton Electric Ducted Fan Jet Talk 3 Dec 20, 2009 04:11 AM
Discussion Sneak Peek at the New Creation Museum Miami Mike Life, The Universe, and Politics 38 May 30, 2007 06:01 PM
Hey Mr. Lin, how about a sneak peek at the Hellcat? splatman GWS (Grand Wing Servo) 1 Jul 05, 2003 05:43 AM