Shop our Airplanes Products Drone Products Sales
Thread Tools
Feb 13, 2017, 05:12 PM
Registered User
Question

Powerlab 8 w/MPA parallel charging issue


First off, I love my Powerlab 8 and use it to charge a wide variety of battery chemistries. I've noticed some strange behavior when parallel charging Lipos. The IR of batteries when charged alone (on the MPA board) shows consistent IR (all cells very close), but when I charge two or more batteries (same capacity, same amount of cells, same amount of charge on them) the IR of cell one reports far higher than every other cell, and far higher than it reports when charging each battery separately.

Occasionally I'll get similar IRs for all cells when parallel charging (what it should be) but most of the time cell one is drastically higher. I assume that this is the reason that I often have out of balance packs when done charging. For example, today I charged two 6S 5000mAh packs at 10 amps each, both starting at about 3.8V per cell. When they were finished, I had cells up to 4.23V and as low as 4.17V. Sometimes despite the crazy high IR it shows on cell one, the multiple packs will be well balanced, but more often than not they are out of balance by .03-.07V, which doesn't seem right to me.

Because of this I've been charging each battery individually at 3C-4C so each pack will charge quickly with excellent balance at the end, but I feel like I shouldn't have to.

Has anyone seen the IR of one cell (cell one on my charger) significantly higher when charging in parallel? My current firmware is 3.33. Could it be the MPA board or the charger? Any other ideas? By the way, this didn't happen when I first got the charger/MPA board about 1.5 years ago when I was on a previous firmware version. Thanks.
Sign up now
to remove ads between posts
Feb 14, 2017, 04:04 AM
Registered User
ggcrandall1's Avatar
It's time to clean all the connector/pins. Get some electronic contact cleaner, I use Deoxit D5, and clean all the pins and sockets on your batteries, MPA board and the charger. https://www.amazon.com/Hosa-D5S-6-De...1529VV0Y2P2BAZ

If that doesn't solve the problem try running your charges with different positions in the MPA board. Possibly there is an open fuse or circuit, that will not show up while parallel charging.

Glen
Feb 14, 2017, 10:08 AM
Registered User
I'll give the contact cleaner a shot. I've tried a lot of different variations with regards to using different amount of batteries over a variety of the 6 inputs.

However, this bit of info may be relevant. I strictly avoid using 2 of the channels on the board as one of them I shorted a battery on ( I think?) as it caused a pop and slightly altered the Deans connector so that it doesn't fit as well. The other connector I avoid, because when used, it basically guarantees that the charger enters the "safety charge" 500mA mode. I don't recall anything negative ever happening to that input, it just stopped working well. Any of the other four will charge single packs to perfect balance.
Feb 18, 2017, 05:54 PM
Registered User
I found the issue. It appears that the MPA to cellpro interconnect cable I was using was not performing properly. I happened to have another one on hand, and once I hooked it up, the IR readings were proper and balancing issues sorted out. I'm glad it was a simple fix.
Last edited by Bird09; Feb 18, 2017 at 06:00 PM.
Feb 19, 2017, 06:24 AM
Unregistered User
vimy g eaou's Avatar
Quote:
Originally Posted by ggcrandall1
It's time to clean all the connector/pins. Get some electronic contact cleaner, I use Deoxit D5, and clean all the pins and sockets on your batteries, MPA board and the charger. https://www.amazon.com/Hosa-D5S-6-De...1529VV0Y2P2BAZ

If that doesn't solve the problem try running your charges with different positions in the MPA board. Possibly there is an open fuse or circuit, that will not show up while parallel charging.

Glen
Hello Bird09, Glen,

This problem has a vague familiarity about it.

Looking back through my posts, I was on a thread discussing similar problems with the V3 Safe Paraboard:

https://www.rcgroups.com/forums/show...tially-serious

Glen, cleaning pins could be the fix for that one too.