LiPo to Li-On Battery swap out.

[deano]

Have decided to ditch the LiPos and create a battery pack of 18650s Li-Ons

I can get 96 18650s into my case. Will be using Panasonic NCR18650B. http://www.ebay.co.uk/itm//112128089731

I am going for a 24s/4p Pack. This will give me 88.8 V

Motor controller is a 9 FET IRFB4110 INFINEON CONTROLLER. http://em3ev.com/store/index.php?route=product/product&path=41_38&product_id=80

Motor is a MAC 500/1000W MOTOR http://em3ev.com/store/index.php?route=product/product&path=50_40&product_id=52

Will the above controller and motor be able to cope?

What 24s BMS is recommended ?

What charger is recommended ?


Goal:- 60 Mile range 30+mph. Level ground.

 

[999zip999]

1800 watts best. Depend on weight and hills. Flat land maybe 2,000 watts. That's a 30 amps controller 34 amp spike. The battery 24s x 4.2 = 100.8 v a little to high for controller. 100.8v x 30amps = 3,000 watts it will melt over time. Time ?
15s x 4.2 = 63 volts 63× 30 = 1890 watts. For long life. 2,500 watts could be a gamble. Hills ?, weight ?

 

[amberwolf]

If your current "LiPo" pack is the same voltage and capacity as the proposed pack, then some of the considerations below won't apply. If it is not, it might be helpful to specify exactly what you already have, and what speed and ranges you get out of it, and what power usages you already see at those speeds and ranges, to help people give better information to you.


24s is a little over 100v fully charged, at 4.2v/cell. Does your controller's specs handle that? If not, you'd either need to upgrade it (replace FETs or caps or other parts), or get a new controller that does.

I don't know if the controller can put out the power you need to maintain those speeds.

The motor would be fine as far as volts go; just rmemeber that if the volts you have now are less than the volts you will have, the speed of the motor at full throttle will be proportional to that.

I don't know if the motor can handle the extra heat from the power you need to maintain those speeds.

The main question beyond controller voltage is whether the cells can handle the current you'll be pulling from them without overheating or having too much voltage sag (especially when they get low on charge). You'll probably want to look up the cell you're wanting to use here on ES (there's a lot of threads about various types) and make sure that 4p will handle your usage.

I don't remember what cells are in a 4p 18650 pack I have here (there's a thread about it with "luna" in the title, if you search threads I started), but it gets warm and cuts off early because it's cells cant' handle the usage my SB Cruiser puts it thru. (which isn't surprising )



I don't know that you'll get anything like the range you're after, though, especially at the higher speeds. You may need more than one of those packs to do what you want, given the extra power usage you'll have just from wind resistance at those speeds, and the voltage sag you may have from the current you'll pull from it.


Oh, and I also recommend looking around ES to find a known reliable supplier, because there are a lot of fakes out there, or recycled garbage. If your proposed supplier hasnt' been used by someone else here on ES to build a pack of those specific cells, with results posted, you won't know if what you get is any good until you get them and test them.

 

[DAND214]

Those cells are only 2c. So at power you will be cooking them. Also, a MAC doesn't like that voltage. My MAC 12t at 18 is good for right around 30 with 26x2.4 tires. At that voltage it runs cool and does the controller. My 8t at 12s is as fast+ and runs cool too.

I would cut back on the S and add more P to the build.

Dan

 

[dogman dan]

Why do you need 100v to go 30 mph with that motor? Seems like just a little bit over 48v should do er, depending on which wind you chose. Possibly 72v, if you chose the 12t. If you have the 8t, then 14s ought to be perfect. 30 amps at 56v (14s) will give you 1500 peak, about right for the max for that motor.

Can't do 100v anyway, your controller is listed as 90v max, and has a high voltage cutoff. Unless, as AW said, you already get it to work with 100v. I'm assuming the cutoff is somewhere above 90v, and below 100.

You'd be better off to run 5 or 6 p at a lower voltage, than 4p at 100v. Because in 4p, those cells will be getting a good whacking on the starts.

96 cells,, 16s x 6p. 60v 20 ah. There is the optimum pack you should build. 67v leaving the garage, 2000w peak power, but still 1800w mid ride. 30 mph should be there even mid ride. Pulling 45 watt hours per mile at 30 mph, you will have 29 mile range. You'll need about 3000 wh battery to go 60 miles at 30 mph. That's more like 230 cells.

19s 5p will also work for your pack space.

 

[wesnewell]

30A from a 4p pack is 7.5A per cell/ They're only rated for 6.8A per cell. Expect a .4V per cell voltage drop under a 30A load. So a voltage sag down from 100.8V to 91.2V. My 4+ yo 20C 10ah 24s lipo pack didn't sag half that much with a 40A controller.

 

[deano]

A massive thanks for the Input. I see now 24s 4p is "mental" and is close to the controllers maximum.

So because my Lipos were total of 62V. I will go for 16s x 6p. 60v 20 ah. That will allow for voltage drop as motor is 48V ?

I am happy with 30 miles range and a speed around 28 to 30 mph. My regular journey is all flat, no hills and I weigh 10 stone.

I got two of the batterys from http://www.ebay.co.uk/itm//112128089731 Charged and discharged them on my I-Max 6 Hobby charger and was getting 3.100mah read out with batterys down to 3.2v. So I guess genuine.

What 16s BMS is recommended ?

What charger is recommended ?

 

[deano]

I have sketched out the battery. The sketch is for one side of my pack, so I will just mirror this. Giving me 16s 6p



I have not a clue on correct BMS or charger. If anybody could help? It would be really appreciated.

 

[dogman dan]

Uh,, yeah,, 16 s does leave you screwed for choices on the charger or bms. What is standard for a 60v scooter? Is that 16s?

I'd start by asking EM3ev if they know where to get. Not sure if you can turn a 14s charger up enough to go 16s or not. I wasn't even thinking bms.

Chargers do exist for lead. http://www.ebay.com/itm/Electric-Bike-60V-2-5A-PC-PORT-Battery-Charger-E-bike-Scooter-Ebike-US-Seller-/321744141076?hash=item4ae971fb14:g:FrAAAOSwcwhVRSvO

16s,, tends to just get you lifepo4 bms.

 

[wesnewell]

Your sketch looks all screwed up to me for a 16s3p pack with voltages reversed, etc. If you're making a 16s balance plug, you need 17 wires. But for a bms, you normally only hook the positive side of the cells to the bms, which would be 16 wires, since they usually parallel the #1 cell negative to their balance circuit. I hope you know what you are doing.

 

[wesnewell]

Oh, you can find 16s bms's for 4.2V cells all over the place. Then use a 67.2V bulk charger to connect to the bms. Or if you prefer to use a balance charger, you can either use 2 8s chargers or parallel each 8s section and use a single 8s charger. That would require you build the pack in 2 8s balance sections and be able to split the mains in the middle.
http://bestekpower.com/592v16spcmbmspcbforli-ionli-polymerbatterypack/
http://www.batterysupports.com/lion-lipo-nbsp-60v-nbsp-16s-c-32_45.html
https://bmsbattery.com/bmspcm/733-10s-16s-50a-lipo-bms-system-battery-management-system-bms-pcm.html#/109-cells_in_series-12
Good luck.

 

[deano]

Your sketch looks all screwed up to me for a 16s3p pack with voltages reversed, etc..

Are you sure? battery starts at No 1 (last column/bottom cell) on bottom image. Top image is reverse side starting at No1 (1st Column/bottom cell)

 

[wesnewell]

I meant it just looked confusing with the voltages/battery images reversed. Would have been much clearer if you hadn't reversed the images, or just made it a simple diagram without trying to show all the details. At first glance it looks like 2 48 cell packs instead of just 1.

 

[deano]

Started new thread at https://endless-sphere.com/forums/viewtopic.php?f=2&t=85469

Had a brainstorm and are going with a 18650 Compression Battery Pack Build.