30kw electric motorcycle build. 8kWh 26S27P

HanzieO

1 mW
Joined
Dec 23, 2017
Messages
13
Hi guys,

I have started the build on a electric dirtbike. Full size and road registered. I am planning to use a hub motor Enertrac MHM603 http://www.enertrac.net/product.php#b this is so I have more space for batteries. I am planning for big range and around town/bush only so 85km/h max is ok. The motor suits that and is watercooled with a 30kw peak rating.

I have got myself a 450 dirtbike frame and 760 Samsung 30q 18650 cells. Currently in in the battery planning stage and have asked a few questions on FB but want to move it here. https://m.facebook.com/groups/125035107565566?view=permalink&id=1553684961367233&ref=m_notif&notif_t=group_comment_mention

I don't want to put this in the battery section as it will evolve into a full conversion once the battery is sorted.
 
To add a bit of complexity I want my bike to be my solar battery aswell when I'm not riding. This will mean I have to split the 96v battery into 2 x 48v packs to connect in parallel while my inverter is changing and discharging it.

I think this means I need 2 x 48v BMS units that charge and discharge through 1 port instead of separate charge and discharge ports. Do I have to run full battery current through the BMS? I think this will get expensive. The likely currents involved will be:

300A at 96v peak drain when packs in series and I'm riding
63A(3kw) at 48v from each pack while charging and discharging via my solar inverter. I can drop this to 2.5kw that will get me to about 50A. Or 5kw total draw for both.

Cost is an issue BUT I will spend what I need to to protect that pack. I'm hoping I can use 2 x 13S BMS units that can deliver 50-60A to handle inverter charge discharge and then take the 96v straight from the pack while riding bypassing the BMS. Will the BMS still be monitoring the Series packs if the drain current doesn't go through the BMS? I'm happy for a alarm or warning that I can act on manually if there is imbalance or low voltage issues while riding. But the inverter charge discharge needs to be completely automated and protected.

I'm open to any and all technical and design suggestions and input. I welcome it!!! I am not open to any questioning the economics of this venture as I already know it's not really economically viable. I also don't care for opinions that say this is not possible. Everything is possible. Man has been to the moon.

I have a dream of my house powering my vehicle and my vehicle powering my house. Off grid. And if I want to use the washing machine at night for example I will just have to not ride that day... But if this works then the car is next. Now there will be 2 batteries and things get interesting.
 
What you want to build is certainly possible, but you will want a pair of seperate BMS's to enable splitting the pack and re-combining parallel for your home energy storage.

You may find you can skip the inverter and just run all modern home appliances straight from the pack 90vdc. Only a few things like a table saw and older refrigerator/freezer or older AC units would care about needing AC over DC (though obviously test to confirm with a current regulated DC power supply before connecting to the pack in the event it doesn't like DC). TVs, laptops, drills, grinders, vacuums, induction hotplates, projectors have all worked fine in my own home tests running my house from my 28S Zero DSR pack during power outages. This doesn't mean everything you try to plug in won't just immediately explode into plasma or have the switch plasma arc from not being able to break DC when you go to turn it off, but it is at least worth testing if what you've got just natively runs safely on your pack's normal voltage without needing to split it and parallel it or buy an inverter and eat it's added efficiency losses.
 
Very interesting reply. One concern I have is in Australia we use 220v and not 110v like you guys. Its a big difference to 96vDC. Most modern switch mode power supplies take 90-240v ac so 96vDC will probably work on those. I dont have high hopes for the 220v stuff.

I will do some trails.
 
I have just emailed the supplier and asked for some pics. He cant Post the pack to me now as I will not be home to receive them. Im shattered because Im so exited.

Attached is a render of what the battery may look like once welded. A bit of wee came out once I saw it rendered on a block and the realization sunk in what I am about to build.

My Qty was incorrect in the first post its 720 cells @ AU$7.01 incl tax each
 

Attachments

  • Battery v1.png
    Battery v1.png
    81.1 KB · Views: 3,294
HanzieO said:
My Qty was incorrect in the first post its 720 cells @ AU$7.01 incl tax each

So $5k in batteries that discharge 15A and are 3Ah
Now if I am not mistaken, ru.nkon.nl would see cheaper, 2.75E which is 50% more in aus dollar, $4.12ausd of course thats not included s/h, which is an extra 175E so $260ausd. I dunno what your import tax would be.
https://ru.nkon.nl/rechargeable/18650-size/samsung-inr-18650-30q-3000mah.html
 
Thanks Markz,

I was only ever going to buy something this important from a reputable local supplier. I didn't even look at any overseas suppliers nor do care to import cells myself.

Here is a pic.
 
My head is hurting today. I have joined 3 x P packs together but Im struggling to to get my head around a safe and proper way to do it.

Can I ask some of you smart guys to have a look and give me an opinion please. 29x 30Q's shoud be good for 290A. this is my goal. On the first bus-bar connection I used 10 of 0.2x10mm nickel strips spotwelded onto the centre of the blocks isolated from the edge cells.
2018-01-16 12.29.22.png

On the second connection I used 50 of 0.15x8mm strips spotwelded on top of each other onto the centre of the brick joining 2 and 3.
2018-01-16 17.35.39.png

I think the first wont carry the current and the second was a real PITA to weld.

Any Ideas thoughts?? Some more pics just to share what I am up to.
 

Attachments

  • 2018-01-06 09.48.48.png
    2018-01-06 09.48.48.png
    67.5 KB · Views: 3,863
  • 2018-01-06 09.49.17.png
    2018-01-06 09.49.17.png
    76.6 KB · Views: 3,863
  • 2018-01-06 15.12.33.png
    2018-01-06 15.12.33.png
    64.7 KB · Views: 3,863
  • 2018-01-06 23.07.45.png
    2018-01-06 23.07.45.png
    71.1 KB · Views: 3,863
  • 2018-01-07 09.24.46.png
    2018-01-07 09.24.46.png
    71 KB · Views: 3,863
  • 2018-01-09 16.20.34.png
    2018-01-09 16.20.34.png
    74.7 KB · Views: 3,863
  • 2018-01-09 16.22.58.png
    2018-01-09 16.22.58.png
    67.4 KB · Views: 3,863
I have no Idea how mich it weighs or what the spoke count is. I have not received mine
 
Went back and saw it has 36 spoke holes, and it comes laced already onto a 18 inch rim, or you going to lace it to your own rim ?

It does look good.

Are you going to use the Kelly Controller they speak of ?

I think Liveforphysics knows of the better controllers to use for Motorcycle applications . If I remember correctly , Kelly is not the best or even near the best to use for your project.

HanzieO said:
I have no Idea how mich it weighs or what the spoke count is. I have not received mine
 
Back
Top