Cellpro Multi4 Announced - Page 5 - RC Groups
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Dec 10, 2008, 09:23 AM
Registered User
DarkStarPDX's Avatar
Quote:
Originally Posted by Howard Matos
Hi,

Originally, we thought utilizing the balancers to facilitate 200 mA discharge feature would be a no-brainer. This is of course why we published the spec before we completed the R&D, and our preliminary testing supported the original assumption. But once we got deeper into it, we realized that it would take additional hardware to make it feasible and reliable. At this point, the decision was to re-design the PCB to meet our previous published spec, or to remove the feature altogether. Had we elected to re-design, it would have meant discarding the first batch of production, plus another 1000 bare PCB's. There would have had to be changes in the charger enclosure to accomodate additional heat sinking, additional components, a price increase, and of course dreaded delays that customers do not tolerate well. When we started to look into it further, we realized that doing all this to give customers a feature which was already sub-optimal (only 200 mA) did not make sense. We realize that some will be disappointed by this change. This is why we broadly publicized it. This is not simply a software issue that can be turned on later. It would require a new design and ultimately a new product. Whether or not we elect to pursue that option remains to be seen. But we are confident that for the money, the new Multi4 will prove to be an exceptional value to meet the needs of the market as a substantial improvement to the original Cellpro 4s charger. After all, this was originally intended to be a charger and a great charger it is. We can't wait to get them out in the field and see the reaction.
Cool, thank you for the explanation. I just thought it seemed kinda weird that the removal of the feature was announced just days before shipping... I actually already have plans to get the computerized battery analyzer from West Mountain Radio to handle my discharging and analyzing so we're good!

I hope the Multi4 ends up being a successful product, I'll definitely put mine through the paces!
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Dec 10, 2008, 09:30 AM
Registered User
I was originally waiting for this charger, I am now not entirely sure. For a company to promise a product on a certain date, and then decide to change a major part of the package AFTER the promised date, the only thing worse would have been to release on time and not have mentioned anything. I have heard the good and the bad regarding FMA, including up to the latest credit card issues with them, I just can't believe that this issue turned up now.
Dec 10, 2008, 09:31 AM
Registered User
Quote:
Originally Posted by Howard Matos
......Had we elected to re-design, it would have meant ........... dreaded delays that customers do not tolerate well.
Dec 10, 2008, 09:33 AM
bad speller extraordinair
TucsonClint's Avatar
Quote:
Originally Posted by Sisyphus
But wait, there is more....
Sisyphus - Enough already.
Dec 10, 2008, 09:35 AM
Suspended Account
Sisyphus's Avatar
Quote:
Originally Posted by TucsonClint
Sisyphus - Enough already.
Dec 10, 2008, 10:52 AM
Mt. Dora, Florida
mtdoramike's Avatar
Come on guys, give FMA a break here. There were so many people that were simply giddy over the release of a new Cellpro charger that had the ablility to charge a multitude of batteries. Yes, it has been a while in coming, but you get an anouncement that it is nearly ready, but there has been some unfortunate design changes. A dis-charge function would have been nice, but how many would have been willing to spend over $100.00 for the extra feature. What people really loved about the Cellpro 4s was how much bang you got for your buck and pound for pound it was the best charger out there for the money and very well thought of by the masses. I don't think it has a discharge function either. But correct me if I'm wrong.

I believe FMA is trying to keep the price comparable to that of the Cellpro 4s since it was such a big seller. As far as the credit card thing goes, I have had my credit card info stolen twice before I even started using it online. It gets hit like once a year like clock work for the past 3 years. It's like on a timer or something. I mean should we draw & quarter FMA for a mistake?

At least FMA is an American based company so if you have an issue, which I had with the Cellpro 4s charger not once but twice and had to send them back. I just received my money back from the second charger that had an issue. Yes. it cost me about $16.00 in all the shipping, but I also got to use a fantastic charger for 3 months. Unfortunately for some reason the Cellpro just didn't like me. I really miss that charger each time I go to charge my batteries on the Dynamite charger I'm using now.

My point is, FMA did me right from the git go until the end. Their customer service was fantastic, which is one of the major complaints that people have had with FMA. The turn around for shipping a charger to them and back to me was a week, you can't beat that. Some people just can't be satisfied no matter what the situation is.

OK, I'm off the soap box now!

Oh, let me add one more thing, every time I emailed tech support I received an email back from Howard within 24 hours each time. Try that with other companies. So even as busy as Howard is, which I'm sure is every bit as busy as a one arm wall paper hanger, he still makes the extra effort to get back with you. My hat is off to Howard.
Last edited by mtdoramike; Dec 10, 2008 at 12:49 PM.
Dec 10, 2008, 12:28 PM
Registered User
SteveM732's Avatar
Quote:
Originally Posted by Howard Matos
Hi,

Originally, we thought utilizing the balancers to facilitate 200 mA discharge feature would be a no-brainer. This is of course why we published the spec before we completed the R&D, and our preliminary testing supported the original assumption. But once we got deeper into it, we realized that it would take additional hardware to make it feasible and reliable. At this point, the decision was to re-design the PCB to meet our previous published spec, or to remove the feature altogether. Had we elected to re-design, it would have meant discarding the first batch of production, plus another 1000 bare PCB's. There would have had to be changes in the charger enclosure to accomodate additional heat sinking, additional components, a price increase, and of course dreaded delays that customers do not tolerate well. When we started to look into it further, we realized that doing all this to give customers a feature which was already sub-optimal (only 200 mA) did not make sense. We realize that some will be disappointed by this change. This is why we broadly publicized it. This is not simply a software issue that can be turned on later. It would require a new design and ultimately a new product. Whether or not we elect to pursue that option remains to be seen. But we are confident that for the money, the new Multi4 will prove to be an exceptional value to meet the needs of the market as a substantial improvement to the original Cellpro 4s charger. After all, this was originally intended to be a charger and a great charger it is. We can't wait to get them out in the field and see the reaction.
This explanation makes a whole lot more sense than "Based on feedback from customers and final design meetings, FMA decided to drop the discharge feature from the Multi4 charger." May I suggest that you change the notice on the FMA website to be a little more clear that the feature was dropped due to reliability concerns. I think we all realized the balancing circuit was being used for the discharge and can grasp the concept that the thermal considerations of a balancing circuit and a discharge circuit are different. The announcement as it is worded makes it sound like there is no technical reason for removing the feature, which is why I previously stated that I think the decision FMA made was poor. Now that you have let us know the true reason I amend my statement to say that I agree with the decision and I think that most of the customers will too if you give them the full picture like you did for us.

Ignore customers that whine about late products , do like Castle Creations does and say that a new product "will be done when it is done" and not give a specific date.

Despite losing the discharge feature (for a good reason as we now know) and the CC issue I agree with everyone else that has voiced support for FMA. I love my Cellpro 4S and heartily recommend it.
Dec 10, 2008, 12:35 PM
Sindland MC SAA
Howard Matos's Avatar
Hi,

Here is the link to the manual:

http://www.fmadirect.com/support_docs/item_1271.pdf
Dec 10, 2008, 12:56 PM
Intensely Calm
write2dgray's Avatar
From manual page 9:
Quote:
Because FMA’s cell balancing technology monitors individual cells, you don’t need to cool
a pack before charging it. Go from flying to charging to flying again without waiting. FMA
cell-balancing chargers are the only ones
that can charge a pack immediately after discharge
without damaging the pack.
LOL. That's crazy talk.
Dec 10, 2008, 01:36 PM
Southern Pride
everydayflyer's Avatar
My favorite:

From Cell Pro 10 Manual

In Low Voltage Restore Mode
,the charger automatically attemps to repair an overdischarged pack. Cells discharged as low as 0.5V may be repaired to as much as 98% of capacity.


To the best of my knowledge Thunder Power 1010C / 210V)was first LiPoly charger/ balancer to automaticly use a reduced charge rate when cells were overdischarged and is still the only one I am aware of that uses an appropiate reduced charge rate.


Charles
Dec 10, 2008, 01:37 PM
Registered User
SteveM732's Avatar
Quote:
Originally Posted by write2dgray
From manual page 9:LOL. That's crazy talk.
Care to qualify that remark? Do you have a reason why FMA could not throttle charging current to a hot battery? Somehow my 4S can accurately guess the appropriate 1C charge rate for my batteries so I don't see why they can't adapt that routine to account for the effects of a hot battery.

Howard, that PDF is formatted/paginated for printing, do you have one formatted for electronic viewing?
Dec 10, 2008, 02:12 PM
Sindland MC SAA
Howard Matos's Avatar
Quote:
Originally Posted by SteveM732
Howard, that PDF is formatted/paginated for printing, do you have one formatted for electronic viewing?
Hi,

Please try it now.
Dec 10, 2008, 03:30 PM
Intensely Calm
write2dgray's Avatar
Quote:
Originally Posted by SteveM732
Care to qualify that remark? Do you have a reason why FMA could not throttle charging current to a hot battery?
Sure, Steve. The statement is, "Because FMA’s cell balancing technology monitors individual cells, you don’t need to cool a pack before charging it." Many chargers monitor individual cells. Your reference to the charge rate being established based on IR (impedance) measurements is accurate, but IR alone can not determine charge rate for "hot" batteries. If a separate temp probe was used, there could be credibility in this approach.

The statement that "FMA cell-balancing chargers are the only ones that can charge a pack immediately after discharge without damaging the pack" is (IMO) bad marketing and very misleading. Many chargers are capable of safely charging a pack immediately after discharge, provided the battery is not too hot and the proper charge rate is selected. That said, I believe it is bad practice to take a battery hot off a hard run (>120F) and place it on ANY charger, including this one from FMA.
Quote:
Originally Posted by everydayflyer
My favorite:

From Cell Pro 10 Manual...
Now that is surprising, I thought for sure your favorite would be (also from Multi4 manual page 9):
Quote:
Overdischarging an A123 pack below 2.0V/cell will damage the cells (contrary to some
reports). The Cellpro Multi4 Charger requires a minimum pack voltage of 1.5V to activate
charging. If an A123 pack is below this voltage, do not try to repair the pack by boosting
voltage. Even if you manage to repair the pack, it will not have many cycles left and the charger
will reject it for multiple reasons (as indicated by displayed safety codes).
???

- David
Last edited by write2dgray; Dec 10, 2008 at 03:36 PM. Reason: typo
Dec 10, 2008, 03:58 PM
Registered User
SteveM732's Avatar
Thanks for clarifying, I also would not charge a hot pack if for no other reason than I am never in enough of a hurry to feel the need to push my batteries and chargers to the limit.

My favorite quote is also from page 9:
Quote:
You can top off packs, or remove them when they are partially charged. There is no way to damage a pack when using the Cellpro Multi4 Charger.
When I was a kid there was a saying "never say never" but I guess if FMA wants to make that boast and then be liable for it that is their prerogative.

I have the following comments/questions from my first scan through the manual:
  • The manual is a refreshing change from the typical charger manual that is a poor translation riddled with bad grammar and spelling errors. Thank you FMA!
  • The specs on page 1 and page 14 (and the website) are slightly different in that LiMn is sometimes not mentioned and 1S is either included or excluded from the list of balanced/unbalanced cell charging capabilities. These are obviously minor issues but I thought I would mention them.
  • The unbalanced connector is never described. What type of connector is it?
  • It sounded to me like installing and updating CCS would require Internet Explorer to be the default web browser. Most people probably don't see a problem here, but I do hope that FMA will work to remove this limitation in the future so that my choice of battery charger does not dictate my choice of web browser. It already dictates that I launch a virtual WinXP machine to run the software so I'd love to see that limitation go too.
Dec 10, 2008, 06:04 PM
Southern Pride
everydayflyer's Avatar
Quote:
Now that is surprising, I thought for sure your favorite would be (also from Multi4 manual page 9):

Quote:
Overdischarging an A123 pack below 2.0V/cell will damage the cells (contrary to some
reports). The Cellpro Multi4 Charger requires a minimum pack voltage of 1.5V to activate
charging. If an A123 pack is below this voltage, do not try to repair the pack by boosting
voltage. Even if you manage to repair the pack, it will not have many cycles left and the charger
will reject it for multiple reasons (as indicated by displayed safety codes).

???

- David
I fully admit that I only scanned over the new chargers specifications so missed that jewel.

So let me see if I have the "facts(?)" striaght. A severely overdischarged LiPoly can be repaired but a marginally overdischaged A123 can not be.

Strange as I have recovered a A123 cell from 0.59 volts and well over a year and many flights latter it continues to perform just fine.

Wonder why A123 Racing states?

Recomended charge and cut off V below 0 C 4.2 to 0.5V.

but then on the other hand what exactly does

Quote:
Overdischarging an A123 pack below 2.0V/cell will damage the cells (contrary to some
reports). The Cellpro Multi4 Charger requires a minimum pack voltage of 1.5V to activate
charging. If an A123 pack is below this voltage, do not try to repair the pack by boosting
mean?

If one has a 4S packs the required 1.5V min. could be meant with 0.4 volts per cell.

I also thought that A123s could be charged without the balancing leads connected so how does this effect the safety codes?

What about the 300 cycles of a single cell to 0 volts and charges to 4.3?

https://www.rcgroups.com/forums/showthread.php?t=732148

Charles
Last edited by everydayflyer; Dec 10, 2008 at 06:15 PM.