Magic Pie Vector 4 running on 63v?

[RooGM]

I read somewhere here that the Magic Pie Vector 4 can handle up to 63v.  That's got me thinking about using my 3 x 5S Lipo packs instead of 2 x 5S and a 4S which I currently use.  The reason being to simplify the charging process.  I can charge 3 x 5S packs in parallel instead of having to charge just two and then charge the 4S pack separately, adding a lot more time and some more effort to the charging process.  The 3 5S packs connected in series would be sitting at 63 volts fully charged.  I would probably wait a few hours between charging and riding to be safe but my question is has anyone else successfully been running their Mp4 on a 15S Lipo?

[Sam.Vanratt]

Hi
the internal Elkos allow a max of 63V (PEAK!) If you use 15*4,3V (4,3V LiPo Max)=64,5V and hear two nice pop's and need a new controller as soon as you use Regen braking. Even when cut of at 4.2V each, it's on it's braking point. With high temperatures Elkos dries out it's electrolyte and is less capable in voltage over time. You will find here surely a few threads about burned out (the FETs are surely 50-70V types as well) controllers. I was told the Mp4 has a better electronics, but as mentioned in old threads GM don't see cutting edge wheelers (overvolting, overpowering and supercharging) as their primary customers, so the electronic is not out for high specifications=> 48V Battery Packs (so 16 LiFePO4 or 20 LTO or 12 LiPo) is the spec....
There are a few here who goes that thin line and hopefully for a long time :-)
Cheers
Sam

[RooGM]

Hi Sam,

Thanks for the reply.  Do you think the larger risk is when using regen?  I don't use regen and have it disabled.  My lipo batteries charge to 4.2v per cell.  It would be so much easier if I could run 3 identical 5S packs in series and parallel charge them all together. 

[Sam.Vanratt]

Hi RooGM
It's hard to tell as I don't have the schematics of the controller to tell the (expected) braking points. Even with Regen disabled the Freewheeling function in the controller will put energy back when you rolling down the hill. When the battery could not put load unto the controller the controller will take it and => right burn out. There has been a few threads about this problem (about 2,5 years ago): how fast (better how much RPM) is  the MP3 allowed to go. With small 20" tires even 40km/h is too fast.
I understand your problem with charging... one of my reasons to take big (20Ah each) industrial cells with external wiring (=8S1P), so I'm only charging one cell (1S8P) with just a different wired charger connector.
Charging internal wrapped batteries at the same time is something I'd not advise. One weak cell (or a strong one which is not so discharged as the other ones) could drop the charging to a minimum when it reaches it maximum point in a short time.
Buying/using three chargers (if you need to start/finish the charging at the same time) is quite worth it as it prolonge the lifetime of every cell. ...
Cheers
Sam

P.S.: Using 14 cells is already over the spec (48V packs), which is only 12...13 cells  on 3,6/3,7 (both have the familiar 4,2/4,3V max) per Cell LiPo/LiIon...