Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Nov 20, 2012, 09:44 PM
Registered User
Seattle
Joined May 2008
66 Posts
Question
Explain the Benefits of the Multi-Port Safe Parallel Adapter (MPA)

Hi,

I own a couple of Celpro 4s' and I'm looking to upgrade. One charger on my list is the PL6. I've been learning about parallel charging, and I've read all the features of the MPA boards, but I don't quite understand what all those features (fuses, thermal indicators, etc) protect me from. Can someone explain?

Also, when using the MPA's do you still have to make sure that all the batteries are in a similar state of charge, or is one of the benefits of the MPA that you don't have to worry about that.

Thanks in advance for any information.
torquenut is offline Find More Posts by torquenut
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 20, 2012, 11:25 PM
Registered User
Seattle
Joined Sep 2007
2,145 Posts
With any parallel board or harness its very easy to accidentally plug one in backwards. Even though the plugs are keyed, the evidence keep mounting that people are still doing it. Additionally if a cell on one of the packs fails in a way that its voltage drops, the fuses will prevent high rates of current from the other cells in parallel from flooding into the weak cell.

This is more common than you might think. Yet many still use unfused boards. Or worse, use this as a reason to stop parallel charging. The MPA addresses these risks.

Traces Burned
http://www.rcgroups.com/forums/showthread.php?t=1620728

Traces Burned Twice
http://www.rcgroups.com/forums/showthread.php?t=1634850

Three Reports of Burned traces
http://www.helifreak.com/showthread.php?t=383073

Balance wire burned
http://www.helifreak.com/showthread.php?t=424281

Wire Burned
http://www.rcgroups.com/forums/showthread.php?t=1670469

Balance Wires Shorted
http://helifreak.com/showthread.php?t=430573

Charge Lead plugged in backwards
http://helifreak.com/showthread.php?t=436224

Balance wires burned
http://www.rcgroups.com/forums/showthread.php?t=1743871

Paraboard burned
http://www.rcgroups.com/forums/showthread.php?t=1773045

Batteries balance wires burned using parallel board.
http://helifreak.com/showthread.php?t=472663
Gregor99 is offline Find More Posts by Gregor99
Reply With Quote
Old Nov 23, 2012, 10:57 AM
Registered User
Chicago 'burbs
Joined May 2006
1,694 Posts
Quote:
Originally Posted by torquenut View Post
Hi,

...<snip>.....

Also, when using the MPA's do you still have to make sure that all the batteries are in a similar state of charge, or is one of the benefits of the MPA that you don't have to worry about that.

Thanks in advance for any information.
It is less important for the packs to have similar states of charge, primarily because the balance tabs fusing prevents currents much higher than 2A from flowing. In other words, if you connect the balance tabs first, before the main charging leads, the packs will tend to quickly come to similar charge states, but with currents that aren't overwhelming.

Anyway, that's what I do, and only connect the main leads some seconds after all the balance plugs are connected. I also will note that I don't connect fully charged packs with depleted packs, but connect packs that I have flown that day, so all have been discharged at least some, and most are probably at similar charge states.

added: Just one more comment--you do need to be a little careful if one of the packs is pretty small in capacity --such that 2A is a very high charge rate for it. If the other pack is a much larger capacity, and also in a much higher charge state, it could be possible that you could be charging the small pack at a very high rate. Not sure how likely this is, because the small pack will raise its voltage pretty fast so the current will drop off fast. But just saying that one should use some common sense.
Alan Hahn is offline Find More Posts by Alan Hahn
Last edited by Alan Hahn; Nov 23, 2012 at 11:03 AM. Reason: added last paragraph
Reply With Quote
Old Nov 23, 2012, 12:24 PM
President, FMA, Inc.
Tim Marks's Avatar
Joined Mar 2008
1,051 Posts
Quote:
Originally Posted by Alan Hahn View Post
It is less important for the packs to have similar states of charge, primarily because the balance tabs fusing prevents currents much higher than 2A from flowing. In other words, if you connect the balance tabs first, before the main charging leads, the packs will tend to quickly come to similar charge states, but with currents that aren't overwhelming.

Anyway, that's what I do, and only connect the main leads some seconds after all the balance plugs are connected. I also will note that I don't connect fully charged packs with depleted packs, but connect packs that I have flown that day, so all have been discharged at least some, and most are probably at similar charge states.

added: Just one more comment--you do need to be a little careful if one of the packs is pretty small in capacity --such that 2A is a very high charge rate for it. If the other pack is a much larger capacity, and also in a much higher charge state, it could be possible that you could be charging the small pack at a very high rate. Not sure how likely this is, because the small pack will raise its voltage pretty fast so the current will drop off fast. But just saying that one should use some common sense.
Hi:

Actually, the thermal fuses limit current flow to 1A, not 2A.

Tim Marks
Tim Marks is offline Find More Posts by Tim Marks
Reply With Quote
Old Nov 25, 2012, 08:06 PM
Registered User
Chicago 'burbs
Joined May 2006
1,694 Posts
Quote:
Originally Posted by Tim Marks View Post
Hi:

Actually, the thermal fuses limit current flow to 1A, not 2A.

Tim Marks
Sorry, I was pulling that current from my memory! But 1A is even better!
Alan Hahn is offline Find More Posts by Alan Hahn
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion 2 CP8S-TP/PQ6S-PAR Safe Parallel Adapters or MPA board traxx de maxx FMA Direct 2 Sep 04, 2012 03:42 PM
Discussion MPA Safe Parallel Module KAW_Concours FMA Direct 2 Aug 21, 2012 08:15 AM
For Sale MPA - Multi-Port Safe Parallel Adapter for XH Compatible Battery Packs dae77 Aircraft - Electric - Batteries & Chargers (FS/W) 1 Jun 18, 2012 03:47 PM
Mini-Review F.M.A. Multi Port Adapter Stumblebee FMA Direct 0 Jan 19, 2012 08:13 PM
Discussion Hyperion 6 Port Parallel Charge Adapter tripleup05 Batteries and Chargers 3 Aug 10, 2011 11:45 AM