Maxamps Thread...
 

Yes I had to remove yet another Maxamps thread... Suprise Suprise... :whip:

As has been stated many times personal attacks will NOT be tolerated...

If you want to raise concerns regarding the new design then feel free - I'm happy that Austin has logged in to comment.

For once why not have a similar technical dialogue that we have with Patrick rather than waste bytes of the usual comments on Maxamps pricing and C rating.

Maxamps pricing policy is there choice - I personally would prefer that they use a different C rating methodology for the NEWBs and would gladly have a dialogue with Austin on that if I actually could.

So PLEASE can we move on?

So I request no mentions of Austin, Jason, C rating or Price in any post...

Thank you

PS If you wish to complain about this please feel free to call Mike or Brian...

In relation to the design - The concept is interesting but my concerns are

- People mismatching old and new cells i.e. run a 2s pack 30 times and then adding a cell
- Charging complexity - swapping to 1S parrallel pack... Especially if you linked a charged and uncharged cell or just imbalanced cells
- Losses etc with all of those connections - There would be a lot going on in a 5s pack...

As i said interesting concept just worry about the practical realities...

Should it also be understood that vendors can not come here and make personal attacks themselves? Calling people bullies and such was an invitation for sure.

Reasonable dialogue has been attempted before but the vendor chooses to sling mud. This happened on a thread in which BrianG brought up ideas for C rating standards.

If this were Castle they would have offered to take care of us, possibly even offering for us to try out "new product A" to prove how well it performed.

You can't really compare the two because they really don't compare at all. PDC is an awesome statesman. He took care of me when his product failed with never a hint that I was to blame. He actually stands behind his product and follows through with his commitments. He also doesn't throw fits and send Joe Ford in to fight battles for him calling his detractors names and what not.

Plenty of CC bashing has been seen on this forum, and Patrick has taken it all in stride.

No prob Chris, I understand and apologize to you and Mike as i know I was part of the "problem".

I too worry about what will happen when mixing different age cells and charging them in parallel.

Interesting concept, but I do not see how it "fits" the way we currently use and maintain lipos.

FWIW, I just PM'd Austin with my contact info if he wants to call me and discuss this in person.

I didn't post up any tech concerns in the other thread, but in addition to what Chris said, there are a number of concerns that don't seem to be adequetely addressed in the current design.

Namely:

-Amp capability of the connectors. Given the "60C" rating, that would put over 300A through all those banana plugs, which look like 4mm plugs. Lots of places for losses, esp overtime as the connections are continually reconfigured. Lots of potential for failures.

-Overly complicated and potential for shorting batteries seem high

-Fragile construction. The connection plugs would be taking a lot of the impact forces that would normally be absorbed by doublesided tape/glue/heatshrink in a conventional pack. This is not where I want forces to be absorbed

-No specs or recommendations on balancing differentials. How far out of balance can these cells be before you plug them together?

-Large surge current potential between two out of balance cells. Normal balancers discharge slowly to achieve balance. Paralleling two cells with ea other will force a charge into the depleted pack. Completely different method. Given the (hopefully) low internal resistance of the setup, large current spikes are quite possible. How does this effect long term performance?

-Safety concerns if the recieving pack does not take the charge well. No internal mechanism to stop a runaway failure if it should occur upon connection

-Large amts of additional weight vs conventional design

-I think some price comparisons are valid, but I won't go into them. Ultimately this design has to answer is if, given the above design penalities and safety concerns, does this represent a significant value above purchasing dedicated conventional packs?

I don't see how.
Perhaps this design has some merit in some small scale/ slow speed applications, but for its intended purpose and application (high speed 1/10-1/8 cars) it seems far too much trouble for any convience benefits.

Oops, sorry for my thread =/

an edgy thread and I wasn't involved? somebody call a brotha....:whistle:

I can't find any constructive criticism for MA's new "multi-cell" packs.

Did you guys watch the informative video? You have to play dominoes with your cells to charge them. What a pita. Were people really having that much hassle with balancers?

A 6s pack would be bigger than Bondo's belly.

Finn pretty much nailed the rest of the problems.

I had to chime in over there. You guys ever see a modular V8? Well I just invented one. I'm wondering if anyone has a spare minute to help me remove 3 cylinders? I'm thinking I want a V5 this week, mileage was killing me with the V8!

Actually that is almost a common setup - some of the v8's etc do actually shut down a bank for fuel efficiency...

I worry abut the safety aspect - Even in the video jason was about to plug things in the wrong way around a couple of times and had to correct himself.

I know this setup is only intended at advanced users whilst I do think that it is very innovative my safety concerns for Newbs would personally mean I not recommend it. I would rather get 2 x 2s and a 3s pack with traditional connections and be able to make : 2S, 3S, 4S, 5S, 7S.


Another thought - Chargers I don;t think will like the 20 amps 3,7v setup as they are going to have to do a lot of voltage reduction... vs a 5amp 14.8v charge

and only the best chargers will even do 20 amps. It's noobs that buy MA, not "experienced hobbyists". They will have dynamite chargers (like freezebyte wants) and not have the discipline to always assure correct polarity.

I can foresee esc and motor failures happening as people try "one more cell" and exceed specs.

I think this is bad for the lipo industry in general. Bad joojoo comrades.

Agree in that a lot of chargers are 5amp 50w - with a 3,7v cell you'd be only using maybe 20W of your 50W capacity charging at 5amp

Don't agree as that can happen with any setup to a degree

Not into joojoo - i'm a touch more positive I actually LIKE that they are trying something new and thinking out of the box - There is a good idea in here; its just not quite right now IMHO.

Ha! I'm not really into joojoo either. Like has been stated there is a lot of room for error, and I would just hate to see lipo accidents cause stricter regulations.

What do you guys think the shrinkwrap + hardcase on every cell will do to lipo temps? Negligible? It can't be good...

I understand they are the first to sell individual Lipo cells to stack like this but people have be doing "multiple voltage" lipos since forever. Its called a multiple packs and plugging them in series. For example, look at Chris's post below...



Also, a guy said it best on rcgroups.com:

Powerpoles are very user friendly for wanting to make series or parallel connections. This is just a spin-off of this.

Money making spin off even?

Companies like Thunderpower, Neu, Hyperion have very clear generations of cells & innovate with new technology & chemistry to offer people the lastest and greatest ( even hobbyking have the nanotech cells that Im sure we're all eager to hear testing results for ). Maxamps innovated by selling cells seperately and have the customer work out the correct assembly prodecure; no fewer than 7 connections with a 6s pack, and 12 male + 12 female connections, made with tiny ~4mm bullets. That isnt progress, thats a health hazard. ¬_¬

I guess all in all I fail to see a market need here.

Smaller, lighter, and less expensive packs with higher c ratings are the way of the future. It's just to much of a hassle to try and get one type of cell to be the end all and be all for all of my vehicles.

I also see too many potential problems here for most to want to mess with them. Trying to keep up with each individual cell and it's cycle number will be a headache in and of itself.

I just see a whole lot of down for very little if any up side.

The only thing i see as an advantage is varying the voltage, for an outrunner direct drive. If you have this set you can adjust the voltage for where you are comfortable then buy solid packs. I would consider it for that and testing it only

They should include an extra lead so that it can also be used as 2 2s lipos, at the price I don't see how some extra deans wire and two bananas with a traxxas plug could hurt.

If there were to be done a more safe way, and you wished to avoid a lot of potential product liability risks, you would design a better connector that would prevent any accidental misconnections.

Something like a modular molex connector into which snapped individually hardcased 1S cells. The connector & cell would be polar so it cannot be plugged in backwards and short a cell. Another molex could snap in the back of the pack for support, and all the structural strength would come from the cases and connectors.

I still think the balancing technique is questionable however, and does not solve mismatch of differently aged cells. Overall I think it has limited market appeal and seems more like a solution in need of a problem

You have to remember, they don't make cells, they just assemble Grade A cells here in America.

I am not too sure about this but I am having a hard time visualizing how this can be shorted. If you plug one cell in backwards, say in the 3s conf, wouldn't it just make the pack a dud. So your leads will either be positive and positive, or negative and negative.

(
+ -
.......)
- +
(......
- +
.......)

As far as innovation goes, it is gimmicky to me.

I think the resource that they expended on this project would have been better utilized to pushing the 5c charge ratings and informing the newer hobbyist about fast charging.

Get the prices down on the 5c capable chargers and power supplies to match. This is the next big thing to hit lipo, 10 min charge times. Only thing keeping it from happening is cost. Most if not all of the new packs are 5c capable, but having a charger that can fast charge a 4s 5kmah pack is costly, 500watt chargers are expensive and not mainstream at all. Now a big hyperion (250watt output model) can do a 2s 5k pack at 5s, and for the t/c or 2wd racers who run 2s I would think it was the way to go...

Just my thoughts.

I could see doing something like MA did with the enerland style cells, tabs on each end of the pack. You could have polarized connectors, permanently attached to the cells, that could only be assembled as a series pack. That way you would not run into getting it wrong. Plus have snap over hard cases that are sized to fit 2s,3s,etc packs, keeping all of the cells together and protected.

You would need some sort of balancer harness, as I do not think parallel charging is a good idea. Or maybe do something like the little HC charger that charges the cells individually, and just hook them up one by one to that. But that requires new equipment, and dis-assembly every time you want to charge or run.

Having to take a lipo pack apart that often is just not smart. There is no benefit to parallel charging, not with the modern internal balancer chargers. I just do not see it...

For testing purposes, maybe, but we know what will work with 95% of the setups run. Not a big market in the other 5%...

It's not the issue of when the batteries are simply connected to themselves, but when you connect the pack to something else, either ESC or charger.

I see the flying gurus are not going for this idea either. So it's not just us RCM bullies after all.

Mods dont cringe, I'm playing nice here and sincere apologys for previous posts.

I just watched the video and my concern isn't so much how they should or shouldn't charged etc because thats ben thoroughly covered. My thoughts are on how the metal plugs are going to prevent these packs fitting a lot of batterys trays. Then the trays they will fit, the metal plugs will likely be damaged from the packs whacking around in the tray during crashes and bad landings. The design of the packs almost seem like a good idea but it's gonna take the right person to utilize the design and not get fustrated with the method of swapping everything around per application and charging.
Def not Noob friendly, IMO they look to be a pita ?

Thank you for all playing by the rules - A constructive maxamps thread... :)

Still the most that would happen is reverse the poles. Most esc and chargers have something to detect this.

OK, imagine a 2s pack. You stack the cells like so for running:

On the left is the jumper, on the right are the wire leads to the ESC.

Now, let's say you forget to re-orient the cells and install the jumpers for parallel charging, like so:

That will cause a major issue!

BrianG, If i'm right, you will get a spark from a closed loop long before getting to the charger. but you are right, that's a closed loop and likely to swell the pack

I see Brian!

I don't think you will even get as far as getting the bullet in before something bad happens.

I pray for the first person who gets the banana in too far!

most esc's fry with reverse polarity

I like Maxamps, they have the slickest marketing that captures their market very well. I've lost count of how many forum users are prepared to have foot stamping arguments defending the brand...compelling stuff

This latest product is interesting. Someone is going to get their fingers burnt...I can't view the video from my current PC but the 'disclaimer' "Note: ADVANCED ELECTRICAL KNOWLEDGE REQUIRED! VIEW OUR HOW-TO INSTRUCTIONS AND VIDEO BEFORE USE." & the idea of people playing with these things at night is a worry

Oh yeah, that will be a very large spark. We can hope that the connector or the jumper blows before the pack goes into thermal runaway.

the video is amusing PBO. Jason almost mismatches them a couple of times, and you have to turn the pack into some sort of dominoes transformer in order to charge it. Good stuff.

He mentions the packs are still water proof, yet there are open female banana plugs in all the cells. How does that work?

Lipo packs are inherently waterproof. The polymer has to be completely sealed inside the casing or you would have a no go. The waterproofing advertisement is a gimmick and something a user could do for less than 10 cents at home. It's basically a coating like plastidip or the like on the tabs, that's it.

I run cheap zippy rhino packs in my SCX10 submerged quite often and have never had a single issue from the pack.

IIRC, they were saying that the tabs/connections were waterproofed to keep corrosion/oxidation away...

It's a very cool idea, but I don't think it will catch on.

Like many have said, there is too much room for error. It's easily possible to short-out cells, but I think (hope) most people would catch that before it caused any damage. My biggest worry looks like this:

/+=====-____(-)
\-=====+\
/+=====-/
\+=====-____(+)

where one cell (in a supposed 4s pack) is reversed in polarity. If you manually set the charger to 4s, the charger will detect the error. If the charger auto-detects (like hyperion does), it will see a 2s pack. If you aren't paying attention and charge anyways that WILL cause a problem. Of course any problem you can forsee with this pack system can be prevented by using caution. However, even I have seen sparks because I was in a rush.

Edit: It may have been implied, but your truck will not run very well, either, if you hook-up a pack in this manner. :mdr:

Since you should not mismatch cells of different usage (age or number of cycles) that pretty much cans this idea.

After you see that you cannot have a pack that you can run as a 2s some time or a 3s sometime, or whatever you get back to the only benefit I can see:

You could run 4 (or 6) of these cells in a few different vehicles that operate on the same voltage, but use either singe or dual battery trays. For example, you have a flux, erevo, and a converted truggy. You run 4s in them all, and they all have castle 2200 setups, and are all geared for around the same speed/draw. So you "could" use the same lipo setup in all and it would be within the parameters of the lipo. Since you can configure these cells you can split them up and run 2 2s packs in the dual trays of the flux and erevo, and then make a single 4s pack to run in the truggy.

There, I found a use for them!!!!! Yay, and this is acutally a good idea if you have multiple trucks and you only want one lipo. This way you can get your use out of the lipo (and the 300 cycle warranty) as ytou could use it in all of your rcs.

Even if you had a 10th vehicle that you use 2s in you could wire the pack as a 2s2p (may have to make your own adapters) as long as it would fit, and get big runtime for bashing. The kicker is that you would want to use all 4 cells all the time to keep them at the same usage level.

I can think of a few setups that I currently have that I could use these cells with. If they are good enough, and I get a 50% discount... Price is still too high, IMO, but the idea is growing on me. Lack of a balance connector is a deal breaker, as I am sure a shizz not going to parallel charge lipo cells at 20amps... Maybe have a dedicated charge board/dealey that allows you to easily plug in all of the cells and has the balancer and main leads hard wired to it?

I can see some versatility here. I always just had specific packs for most of my vehicles, as I bought lipos used and really did not have a ton of money in them, nor really used each pack all that often. But for a user that has a few rcs and runs on the same voltage there could be merrit.

Since I have a bunch of loose fp cells I may give it a try designing my own setup that does this. Would be good for my boats, and in the few 4s vehicles I have. All my 6s stuff has the same tray and uses the same lipo.

I watched the video. Looks easy to make a mistake & as a consumer I'd be more interested in avoiding the headache of numbering my cells to keep track of cycles & charging, losing all the connectors, breaking all the connectors etc & just buy another complete pack. As long as HC are still selling, it's hard to justify needing all those MA bits & pieces just to have a run

Having said that, I'll bet they sell truckloads of them

Anyone that's been around RC for any length of time, knows Lipo Packs have special needs.

Someone just getting into the hobby, for example, will ruin a few good packs before they suddenly "discover" they should have used a low voltage cutoff.

After feeling the hit on their wallet, this person decides its time to learn a little more about batteries and why they didn't get their money's worth. Who's fault is this? It's a learning curve.

With this stackable cell configuration, there are just too many things that can go wrong.

With the unknowing new person that is just getting into the hobby, there are too many things that can and will go wrong.

Electricity just fascinates people. Have you ever seen someone that wasn't savvy on electronics try to "fix" something?

They may just decide to wire the thing up an entirely different way to see if it works now. LOL

When something goes wrong with a setup, you can bet, if it can be plugged up the wrong way, they are going to try it. Just to see if that fixes it. Afterall, it should work. They paid ALOT of money for this thing. In their desperation, this WILL happen. Then who's fault is it?

I would NOT want to be facing the blame game over liabilities when the unknowing gets together with poor engineering practices. :whistle:

Why are most power plugs reverse polarity protected? So the Unknowing, won't plug it up wrong! It doesn't matter what color things are! If it can be plugged up wrong, it will be! LOL

Two cells, connected together wrong, if the plugs actually plug and weld together, will go ballistic before anything can be done about it.

4S configuration, with the last cell backwards, will attempt to reverse charge the backwards cell, using the force of 3 cells to do it, as soon as the ESC is switched on.

These scenarios are NOT pretty.

When bad things happen like this, it isn't going to be a blame game over warranty issues. Or "We won't warranty that, but we will sell you another one".

It's going to be lawsuits over people getting hurt and property losses.

What about the pissed off parent that just bought this "toy" for their child?

Why did the house burn down? Who's fault is this?, says the insurance company.

Before you release these to the public and start selling truckloads to the unsuspecting, and the unknowing, you better rethink this one Maxamps.

Something like this, could lead to your demise as a company.

If any Mod feels like what I have posted is unreasonable, or if you consider this to be "just bashing", please feel free to delete this post. - *** Its fine as I read it , expresses my concerns - Arct1k ***

Thank you.