FMA Cellpro PowerLab-8. Parallel charging .??

[akouzmit]

I am looking for the charger to charge two 6S LiPo batteries as a single 12S battery in order to balance each cell equally.
For the last 2-3 years I have been using FMA Cellpro 10S charger for 2x5S=10S batteries, but now I am moving toward 12S and I am looking for a single charger with 12S capability.
I contacted FMA with my question and they recommended to use FMA Cellpro PowerLab-8 and charge two 6S packs in parallel.

QUESTION: WIll be the balansing in such parallel configuration performed well on every cell from every battery?

Thank you.
AK.

[TJinGuy]

Here is my article if you would like to read it.
https://sites.google.com/site/tjingu...allel-charging

[akouzmit]

Originally Posted by TJinGuy

Here is my article if you would like to read it.
https://sites.google.com/site/tjingu...allel-charging

Thank you very much for very informative site.

[Gernejr]

Great write up THANKS

[tribe3]

Originally Posted by TJinGuy

Here is my article if you would like to read it.
https://sites.google.com/site/tjingu...allel-charging

I came to this forum to see if I could parallel charge packs with same cell count but different capacity.

Peace

[Jeff396]

Wow Tjinguy, great write up!!

I'm looking to get the FMA Power 8 also but am a little unclear about power supply requirements to take advantage of its power. I am interested in charging two 5000 mah 6s batteries in parallel in the shortest safe time possible. What size power supply would I need to do that in say 30 minutes? I'm new to this electric thing so It's all a bit fuzzy

Jeff

[Howard Matos]

Originally Posted by Jeff396

Wow Tjinguy, great write up!!

I'm looking to get the FMA Power 8 also but am a little unclear about power supply requirements to take advantage of its power. I am interested in charging two 5000 mah 6s batteries in parallel in the shortest safe time possible. What size power supply would I need to do that in say 30 minutes? I'm new to this electric thing so It's all a bit fuzzy

Jeff

Hi,

Here is a good supply I highly recommend:

Mean Well RSP-1500-24

This supply will allow full operation of the PL8.

[Jeff396]

Youch!!!! That's a bit more $ than I was lookong for....at least for now. So the question I have is how can I tell how fast charging will be with that charger and different amp levels of power supplies on the 5000 mah packs. I am currently using a Turnigy acucell 6 with a 20 amp power supply. It took 80 minutes to charge the 5000 mah batteries putting 2200 mah back in the packs. My friend with an FMA 10 is recharging his 2200 mah packs in around 10 minutes where my setup can take just over an hour.

Jeff

[TJinGuy]

Originally Posted by Jeff396

Youch!!!! That's a bit more $ than I was lookong for....at least for now. So the question I have is how can I tell how fast charging will be with that charger and different amp levels of power supplies on the 5000 mah packs. I am currently using a Turnigy acucell 6 with a 20 amp power supply. It took 80 minutes to charge the 5000 mah batteries putting 2200 mah back in the packs. My friend with an FMA 10 is recharging his 2200 mah packs in around 10 minutes where my setup can take just over an hour.

Jeff

Time for some math Jeff. My site covers all of this and more btw.

You want to charge a pair of 6s 5000mAh packs quickly, like in 30min. Well that is approx a 2C charge rate. Here is the math to figure out just how many watts that will require, because watts is what this is all about.

Watts = Volts * Amps = 2 * (6s * 2C) = 2 * (25.2V * 2(5A)) = 504W

So you will need a charger output of 504W to charge what you asked about. Now lets figure out how much charger input you will need to output 504W. To get this number we have to make an assumption, we will assume the charger is only 80% efficient. So we will need 20% more wattage on the input than the output.

Watts(in) = 504W + 20% = 605W

And that is the number you were effectively asking about. To figure out the other PS numbers, volts and amps, you have to assume a voltage and then plug it into the same equation above but shifted around alphabetically. So lets assume you want a 24V power supply.

Amps = Watts / Volts = 605W / 24V = 25.2A

One last thing for you to consider. You only have 6s packs, so you have no way of using the full 1344W output of the PL8. Instead you will be limited to 40A. So keep that in mind when you are sizing a power supply. In other words Howard is correct that the 1500W RSP series Meanwell is a nice match but it is nearly the most expensive PS you can buy. There are many more, much less expensive, options.

[Jeff396]

Thanks, looks like I've got a lot of reading to do before a purchase.

I would like to make one of the anti spark "Y" harness as that really freaks me out when I connect the batteries. I feel like I'm welding. I assume you connect the bullit connector last but how do you decide on what size resistor to use or doesn't it matter?

Again, great web site, very helpful!

Jeff

[TJinGuy]

Originally Posted by Jeff396

Thanks, looks like I've got a lot of reading to do before a purchase.

I would like to make one of the anti spark "Y" harness as that really freaks me out when I connect the batteries. I feel like I'm welding. I assume you connect the bullit connector last but how do you decide on what size resistor to use or doesn't it matter?

Again, great web site, very helpful!

Jeff

Really the spark is no problem. It can be worse on some connectors, especially Deans but the shielded ones are no big deal. For example my 12s 550e makes almost no spark when I connect it. Besides the spark is on the rim and the current is passed on the sized of the connector, so it really is not a problem.

[Tim Marks]

Hi:

We have developed a very useful tool to answer all your questions about power. Check the following PL8 tabbed page titled "Resources". Click on the 2nd link of the tab to download the PowerLab 8 Power Calculator spreadsheet. The latest version supports v1, v2, and even has a custom settings sheet. Let me know if you have any questions.

http://www.revolectrix.com/pl8_links_tab.htm

Also, with regard to your concern about sparking, if you are worried about the connectors sparking when you plug the pack into the PL8, we got you covered already. If you follow the recommendation in the manual and plug the balance connector in first, we have included surge protection circuitry that discharges the output capacitors instantly. There is little to no spark on the balance connector, and there will be no spark on the discharge leads when you connect those up.

Tim Marks

[Jeff396]

Thanks Tim!

I get no spark when plugging into my current charger. I was talking about when I plug the batteries into the ESC on the heli. I am using a Y harness with Deans connectors. One of the guys at the field questioned whether those connectors are adequate for my application. He didn't know either as he's into smaller electrics currently. I have a Trex 700E running the stock Align 5000kv motor with a 160 Amp CC esc with two 5000 mah 6s batteries. Are Deans okay for that?

It is kinda fun to freak people out when connecting the battery): First time I did it was when it was dark. I though I ruined something!!!

Jeff

[whytlotus]

For what it's worth, my PL8 v2 arrived yesterday. Hooked it up to a Meanwell RSP-1500 24 and charged a Hyperion 12s 4500mah split pack in parallel. From a storage charge of 3.79 volts per cell, I put back 2645mah to fully charged 4.2 volts per cell on the high rate of charge setting. It was set to 34 amps. Done in 17 mins 11sec. I use 5.5mm bullets and had no sparking upon connecting. One word.....SWEET!

[Jeff396]

Okay, been reading when time permits. I just realized that my current Turnigy Accucell 6 is only charging my new 5000 mah 25C Thunder Power batteries at 2.2 amps though I set it for 5 amps. Am I correct to assume that the power supply is not up to the task or could it be an issue with the charger or is that normal? Charge times are from 1.5 to 2 hours with a 60 to 80% drain on the batteries. The power supply is a 12 volt 20 Amp unit but it doesn't list its wattage.

Jeff

[Gunnarjohn]

The Accucel 6 charger is a 50 watt charger so if you a charging a 6 cell battery (25.2v fully charger) at the start of the charge it can push the 2.2 amps (battery at 22.72v or 3.78v per cell) 2.2 amps X 22.72 volts = 49.98 watts.

[Jeff396]

Thanks, that helps a lot......time for a bigger charger!!!

Jef

[BRUSKI]

What are you going to get now Jeff. You just need 20000 packs and alot of cheap chargers and you will be fine. If you like I can bring a cord to the field and we can hook it up to our trucks so you can get some extended flights, LOL.

See you this weekend.

[Jeff396]

Bruski,

Has solar power been looked into

Beren's in pieces.......again! Waiting on parts So it's gonna be a very oily weekend!

Jeff

[Jeff396]

I got my new PL8 FMA charger. After a day of disappointment I finally figured out that going to the faster and fastest charge levels did not mean that you were charging at a higher C rating.........I read the directions Now I'm charging my Thunder Power 5000 mah 6s packs with an 80% drain at 2C in 30 minutes. I'm still using my 12 volt 20 amp power supply. Today I'm going to try parallel charging both packs at once! This thing is great!!!!

Now I just need to get my 42 Amp 24V power supply from Feathermerchant wired and life will be good

Jeff