Yes, please show more pics, sides, back, etc

Originally Posted by misternatural

Well, I'm not skilled in the field, but what finally dawned on me as a layman is that they should promote:

1. You CAN PUSH ONE BUTTON to get the charge or discharge going if you want, and don't have to go through a whole series of them, UNLESS you want to;

2. YOU DON'T HAVE TO BUY AN EXPENSIVE POWER SUPPLY since it can run with what YOU ALREADY HAVE, and if you don't have a power supply, YOU CAN START WITH WHATEVER YOU CAN AFFORD CONSISTENT WITH YOUR PRESENT NEEDS;

3, These things are more than chargers, and are really diagnostic devices with fully functioning computer interfaces; and,

4. Though assembled "off shore," you have U.S. telephone support from guys who know what they are talking about AND YOU CAN GET REPAIRS, not just discounted replacements.

Now, if that doesn't convince someone to not buy Chinese, I don't know what will-PUT ALL THIS IN ADVERTISING SPEAK, FMA!

You might ask, "How do you know all this?"

Well, I bought a boatload of Chinese you know what believing you need a honking big power supply for top-end FMA products, etc.

My bad.

Hi:

Point taken. We'll see if we can run some PR with "tech talk" toned back down the road.

Thanks for the ideas too!

Tim Marks

Originally Posted by Speeddaddy

Yes, please show more pics, sides, back, etc

Hi:

Will see what we can do. Need a little time. All we have right now are engineering prototypes, and they don't look so great.

Tim Marks

Hi:

We just posted the new PowerLab 6 Power Calculator spreadsheet on the Revolectrix web site. Go to the Resources tab page (link below), and click on the 2nd link of the pane to download a zip file containing the Excel spreadsheet.

http://www.revolectrix.com/PL6_links_tab.htm

The Power Calculator has questions and answers to the most common questions about Input Power Supply as well as output batery amps and currents which can be attained when using the PowerLab 6. Plug in your information and the calculator shows you the results.

This is release 1. If you see any problems, or have any questions, be sure to let us know.

Tim Marks

Hello,

Electric newbie question here.

I am trying to decide between the powerlab 6 and the powerlab 8. I am purchasing an 800 W 24 V power supply, and I don't forsee my needs going beyond this. However, I plan to fly one aircraft that will take an 8 cell pack
(2 4s packs). I think the 6 is more appropriate for my needs in terms of price and wattage, but I would need to charge my 8s as two parallel 4s's.

Is it worth the extra cost to get the 8 to charge my 8s? My main concerns are safety, performance and longevity of the battery, rather than charge time.

Thanks for any help!

PL8 will be larger, so if you are field charging consider how you will carry it. Because parallel charging does a less than perfect job balancing, you would get better results from the PL8. Having recently expanded to two PL8 setup, dual charging in a master/slave config is quite nice. IMO, two PL6's would be much nicer than one PL8.

But that's quite a bit more than you are asking for. Given your constraints, I would go with the PL8 and avoid parallel charging. If you have plans of running dual 6s packs at anytime in the future, dual PL6s would be better in the long run.

Gregor99,

Thanks, that is helpful! I did not consider the dual charging perspective. I probably wont get there, but it is interesting to think about. Your comments are making me lean a little bit toward the 8.

Originally Posted by Gregor99

Because parallel charging does a less than perfect job balancing.

Care to elaborate?

Two cells in parallel, by definition, will soon be at the EXACT same voltage. As such, charging two 4S packs in parallel will be no less perfectly balanced than charging the two packs as an 8S pack.

One could even argue that the parallel charged packs will be better balanced as fewer balance circuits (that are subject to subtle calibration variances) are involved.

As such, I would save the $$, get the PL6, and have money left over for more batteries.

Mark

Originally Posted by mrforsyth

Two cells in parallel, by definition, will soon be at the EXACT same voltage.

But the question is "How soon?" The answer might surprise you.

See posts 3226 through 3229

http://www.rcgroups.com/forums/showt...76112&page=216

Originally Posted by mrforsyth

One could even argue that the parallel charged packs will be better balanced as fewer balance circuits

One could also validate a theory and take measurements as I have. Perhaps parallel charging produces a more balanced pack(s) than an inexpensive chinese charger can produce. But in my tests with a PL8, balancing accuracy was 10 times worse charging more than one pack. I guess the FMA products have spoiled me and I've come to expect a better balancing result than is possible with parallel charging at greater than 0.5C charge rates.

Originally Posted by Gregor99

But in my tests with a PL8, balancing accuracy was 10 times worse charging more than one pack.

You must have either: A) Poor parallel cables, or B) very poorly matched packs that have a tendency to go way out of balance.

I have been parallel charging multiple packs on my iChargers at 2 to 3C charge rates for years and I have never had deviation beyond 1mV as measured by my Tektronix DMM. But then I use high quality parallel cables that I made myself and I exclusively purchase good quality packs.

Mark

Originally Posted by mrforsyth

I exclusively purchase good quality packs.

For the reasons Charles cited on that thread, the issue is going to less severe with higher quality matched cells. The cells I tested were Voltz, NanoTechs and Hyperions. Except for the Hyperions, not the best cells. However I would guess they are the quality that is typical for most modelers. What packs are you using?

Follow up questions:

Is there a commercial adaptor that allows the pl8 to charge 2 4s packs as one 8s? My understanding is that fma does not recommend this option due to potential safety issues:

http://www.rcgroups.com/forums/showthread.php?t=1437834

Would it be correct to infer that the pl8 is basically a 6s charger unless you are using packs with fma connectors, or a non-fma serial adaptor for greater than 6s packs?

Thanks!

Originally Posted by Gregor99

What packs are you using?

My most used packs are Hyperion, Gens Ace, and Billowy Power. All of these have proven to be quite well-matched with respect to capacity and internal resistance. Posted my experience with these here. Will be buying more of the Hyperions and Gens Ace when my current packs finally go south.

Mark

When I ran 8s in one of my helicopters and had Bob Fix make me enough 4s to 8s adapters to perminantly attach them to the packs. I left the pack's discharge leads configured in series and never seperated them. It was always charged and used as an 8s pack.

Send Bob a PM for pricing
http://www.rcgroups.com/forums/member.php?u=160513

This was before had a built up some stock of connectors. Today make my own adapers. For safety I would leave them attached to the packs.

EDIT: PL8 thread for further PL8 discussion
http://www.rcgroups.com/forums/showt...76112&page=222

Originally Posted by lgibjones

Follow up questions:

Is there a commercial adaptor that allows the pl8 to charge 2 4s packs as one 8s? My understanding is that fma does not recommend this option due to potential safety issues:

http://www.rcgroups.com/forums/showthread.php?t=1437834

Would it be correct to infer that the pl8 is basically a 6s charger unless you are using packs with fma connectors, or a non-fma serial adaptor for greater than 6s packs?

Thanks!

Hi:

The PL8 is an 8s device. The adapters which support the Cellpro batteries do go up to 8s. The adapters which support all other brands go up to 6s. This is because, at the time they were engineered, nobody was offering anything > 6s. If you need to adapt another brand's 8s battery to the PL8, you can do it a couple ways:

1) You can purchase Cellpro 9 pin battery pigtails, cut off the other brands balance connector, and solder ours on (one wire at a time). Then the pack will plug directly into the PL8.

2) Or, if you want to be able to connect to the PL8 via a Cellpro adapter, install 2 Cellpro pigtails to your pack; one 5 position, and one 6 position. This is a good idea if you want to charge these packs in parallel. Then they will plug into the Cellpro Safe Parallel Adapters.

Following are the links to all the pigtails I mentioned above, as well as a link to the Cellpro battery pack wiring conventions.

9 position Cellpro battery pigtail:

http://www.usastore.revolectrix.com/...-10-9-Position

5 position Cellpro battery pigtail:

http://www.usastore.revolectrix.com/...-10-5-Position

6 position Cellpro battery pigtail:

http://www.usastore.revolectrix.com/...-10-6-Position

Cellpro battery pack wiring conventions:

http://revolectrix.com/support_docs/item_1315.pdf


Any questions, just ask.


Tim Marks