13AH 18AH Battery Mix or Not

[vipertriplex]

Just a little quick advice is all I seek.
I am presently running a Twin Motor Setup of a 5000w rear hub motor and a 2000w front. This setup was to have a 86v 13AH 100A continuous battery installed but never made it to the build at the time of shipping. Instead, the 100A battery was substituted with a 86v 13AH 60A continuous that leaves the bike amp starved killing the bikes performance. After repeated complaints to the manufacturer of the rig, they sent me another battery of 86v 18AH and they say its 100A continuous but doesn't state it on the battery. Now after installing the bigger 18AH battery I did notice an overall increase in performance as well as top speed but still not exactly what I was expecting. My CA is giving me a reading of only 62A at full throttle and I have it set for 70A max but never seems to get there.
What I was thinking was to parallel the two batteries to get me to that 100A continuous in order to use this rig at the intended operating range or would this be a bad idea? I had also purchased a Cromotor V3 that is going to replace the 5000w rear motor and the 5000w is taking the front seat eliminating the 2000w from the build. A Lyen 24FET is going to power the new rear only after I can find someone who can beef up the Controllers Amp Capabilities to better then 60A. Not hard to see that extreme speed is what in after.
Im new to this whole Ebike thing so if there is any additional information you require to better advise, please feel free to ask and thanks...

 

[vipertriplex]

Actually what I have are UN 38.3 Certified Li-NMC Batteries. As for the exact cell model would mean I would have to open up the pack thereby voiding the warrenty. These are pretty expensive packs and from what I understand were designed for minimal voltage sag.

 

[vipertriplex]

First and foremost I would like to that you for your replies concerning this topic.
I was really trying to avoide throwing these guys out there but if it would help to better advise the company is HPC
The bike is the XC-2. Crystalyte 5000w Revolution motor in the rear with a Crystalyte 2000w H 2480 motor up front on dual Crystalyte controllers. Must admit that this bike left me with a bad taste in my mouth. Was nothing like what I expected. I come from I long and painful background in motocross as a kid then jumped into sport bike to a Roadking. When the idea of having a bicycle with the capabilities of tuned down moto came up, I couldn't pass up the chance. Sadly, it would appear I have to keep searching. As an exterist Im forced to ride it till the wheels fall off. Ive read all the web pages I could now come here in hopes of finally answering the question of if it can be done.
What I seek is an all out balls to the wall, neck jerking 100mph Beast!!! They say the Cro could get me closer to my mark so I picked up a V3. Ive read a lot of good things about Lyen so I picked up his 24FET Freeway controller. I knew going into this that rebuilding was going to be something unavoidable am I on the rite track. I chose HPC because of its low weight that looks more like a bike then a Dirtbike.
Any suggestions that would greatly increase my overall speed or more then welcome. Ive been gas powered all my life but its never too late to learn a new science.

 

[vipertriplex]

The batteries are also from HPC. Prismatic Pouch Cells from my understanding. First one is HPC ELITE 90V 13Ah Li-NMC Ultra High Performance Battery. The second one is also HPC Elite 90v in 18AH but this one supposedly is in an HD version that supposed to put out 100A continuous, yet Im not so sure. In the world of cars I can always put a load tester to the battery to see its actual output, respectively. With my minimal experience concerning these batteries Im not so sure of that being a good idea in testing these batteries or can I? If not then what would be the most accurate way of testing the output of these batteries. Also, would they be safe to parallel? Ive read a lot of articles concerning the mix of different AH packs to not be a wise idea and is this something you would do?
Thanks again.

 

[vipertriplex]

I fully agree with you.
Only after searching the internet for a few hours did I come up with something like the info you asked for.
I read an post from a member who stand that HPC was somehow very secretive about the type of cells they use and boast of how their cell technology is exclusive to them and their suppliers. Thats a petty big claim.
I then came across this video https://www.youtube.com/watch?v=GcggKY9l7m8
Here he went into detail concerning the packs and gave a pretty accurate account of their capabilities.At least to my understanding.
The cell tech is lithium manganese cobalt in both packs. The 90v 13AH is rated at 7C/12C Burst. The 90V 18AH is rated at 10C/20C.
Alone on the bike, both packs preformed well I guess. Its only when you hit both throttles to full that leaves me somewhat dissatisfied. The front motor would cut out on me at times only because insufficient amp draw from the 13AH battery and would only preform well just after full charge. With this battery I wasn't able to exceed 40MPH
Now, with the 18AH battery performance was much better and consistent through the discharge and put me at a 49MPH top end. Is this due to the max capabilities of the motor?
Again I tried to find stats on their 5000w Revolution motor and found nothing. I went over to the simulator as you advised and ran the numbers using the 5403 model only to find that what I was getting out of my rig was just what the simulator predicted. Pretty Cool! This is pretty much what I expected but needed to make sure there wasn't any stones I left unturned that could boost my speed. So, now I throw in the Cromotor V3

 

[docw009]

No one mentioned running each motor off its own battery? They're only sharing the battery right now?

 

[vipertriplex]

You know... I was thinking about just that today... The only problem I would have there would be connecting another CA to keep track of the pack which would be too dam confusing, or I could always throw on a little digital volt meter or even a BMS screen. I was planning on changing over a few things and one of them was to change over both controllers. I was planning on going with either a Kelly or an Adapto 14kw to power the Cromotor V3 thats will be going in the rear. The 5000w Revolution motor is going up front using the Lyen 24Fet meaning even greater Amp demands from the two. Last time out I was powering a 7000w setup, now I hope to cram 14kw into the two. I believe the only way I would be able to use this setup efficiently enough would be to parallel the packs......... Or should I just go with a whole new custom battery.... Was thinking something in 32S and use the other two for future project bikes... I have 2 in the works now...Im hooked... But like all things, this will take a little to get the hang of, but thanks to the help offered by members like yourself amberwolf and others, I think Ill hit my mark, or get dam close... That and better battery technology...

 

[vipertriplex]

Can mean there's BS involved somehow, whenever vendors refuse to give out info like that.

I went into this without any knowledge concerning ebikes or what it took to make them go fast. Ive broadened my knowledge a bit since but chose to do business with this company on account of a couple of good reviews Ive read, along with a handful of videos that I was sold on. Like any gearhead, Id just buy myself a High Powered bike, reverse engineer the thing, learn the available science at present and see what I could do to improve on it. Ive been doing this all my life. All of this is made so much easier when you know exactly what it is you have and what it is capable of at the very start. I was under the impression that because these guys knew how to make a bike fly that perhaps they might be able to fill me in on the more advance stuff. Sadly, the only thing thats been flying from the start was the BS

Without a manufacturer spec sheet, I wouldn't believe anything unless I tested it myself. (and unless it's a known-trustworthy manufacturer, I'd still test it myself)

What I would really like to do is send the batteries out to have them completely evaluated by an outside source.Ive been dealing with high amps all my life but in 12v. 100+v is german to me and my available toolset. I was tempted to put my 12v load tester to it but was afraid Id blow out my meter. How am I going to explain that to my Snap On guy. Bottom line, Im the one dealing with them and sadly, I don't trust these guys at all. I knew I would find myself on one of these forum eventually because there are somethings that are better off explained.

If that doesnt' happen on the rear wheel under teh same conditions, given that it is supposed to be a much higher power (higher current) motor than the front, then that means the controllers are not both setup with the same LVC, which is pretty wierd for a bike meant to be 2WD and running off just one battery--they should be setup with the LVC for the battery pack provided with it, and both should be the same.

I questioned this exact same thing and was told that the front motor was set to a 40A max (governed by the CA. from what they explained, the CA was connected to the front controller, set to a 40A profile them removed. Ive say that were possible) then that the rear was set to 60A thereby utilizing the batteries continuous 100A output. The front wheel was not to be run continuously but mores as a speed booster to get you to top end a lot quicker. Not putting any crazy demand on the battery and operating within its constraints would insure long life... Ill go with that... Problem is I never got a 100A battery. My 100A HD battery was substituted for an Elite 60A. And that is a whole other story... WOW... Anyway, The best I could get was what I have now and either i have to make these work or spend a few grand on a whole new pack.

If it happens on *both* rear and front under same conditions, then it means the battery's BMS is cutting out on it's own cell-level LVC (or overcurrent protection if it has any), to protect the cells.

The rear goes shortly there after

I don't know, because I don't know what your motor's winding is (K/v). You can play wiht the simulator with your approximate setup and see what it's max speed should be, and it should at least be close to what you get in reality. I'm not sure if you already did taht based on your post.

I ran the sim but again couldn't get the exact stats because HPC has their motor model number on it. Now again they say they have a special winding that have no available stats. I used the 5403 model of the Cry because thats what it best resembles. Seems that the numbers I have been getting (and it came within 1.7 mph to my actual) were from a battery of 62A. This is why I figured Id just parallel them to get them to their projected values. But I really would like to know what I have at present. Perhaps someone knows of an outside evaluating source.

 

[pdr]

You can always parallel packs as long as they are same chemistry, number of series cells, and state of charge. Best also if they are same age, but if not it still works.

There is another subject in Endless Sphere running on the matter of parallel batteries ("Portable Range Extender"). Where one member posts that he is using different batteries in parallel for years with good success.

So me and many in the community want to find out finally the last word about the promising possibility of combining batteries. I guess a simple answer on such an obvious matter is available, but where?

Here goes my question:
Putting batteries in parallel must be the best thing reducing the current drain and voltage sag from both batteries and increasing you range. Perfect! A many gents and dames are looking for this, the golden egg, the way to maximize ecologically the lifetime of a battery which would not serve stand-alone,
BUT: it is not simple connecting in parallel, there is something more to it. To start with how to coop with (unintended) difference of voltage because of different SOC?
And secondly, once you prevented flow from on battery into another, is there any other risk of a just plain parallel connection of two different batteries, let us say, for example
a new 15Ah 36V 2C lithium battery 100% charged together with
an old 10Ah 36V 1.5C lithium battery 80% charged and of slightly different chemistry?

So please which basic circuitry (only diodes?) is needed to have it save, simple and functional? Could you hint us, newbies, on that? Thank you so much!