40ah esr750 hoverboard build

[silviasol]

Just about finished with my 40ah build! Upgrading all the wiring from the controller to batteries and motor to have more flexible wiring. The pack is build of turnigy 5ah 20c cells. Just about as much as you can possibly fit in the pan with a deck spacer.
Costs:
56 cells @ $9 each $504
4x bms/pcm @ $90 each (When new from batteryspace, I salvaged them from dead stock goped lipo packs)
= $900 for a scooter with more amps then the lipo goped's 4k+ price tag! With cells that get 15-20% more range amp for amp! I have just $1200 into the scooter now

Connected cells to 10ah

Adding thermal compound to the controller heatsink to battery pan, maybe will help keep the caps cooler?

Wiring and packs securely fit. Now just to finish the controller wiring, charging port, and waiting for my battery wrap to arrive

More to come this week! Can't wait to test the range on this beast!

 

[torqueboards]

Great photos and build. That's some mad range. LOL! I would imagine on my skateboard I would get at least 48 miles if not a 20-30 more miles LOL. How heavy are those batteries?

 

[silviasol]

Thanks. They are about 7lbs each. The entire scooter will be 70lbs, very heavy.

 

[melodious]

Put a hinged lid for EZ balancing access to the batteries. I've seen a build using a thick slab of clear plastic (the bulletproof stuff you see in a bank teller's window) which was hinged & bolted on the side for easy access.

 

[silviasol]

I have seen a few with the hinges. I just bolt the spacer down with three of the bolts then just one bolt for the deck on the back corner.

 

[omfgitsmateo]

Any update? A step by step walk through would be awesome!

 

[Silenthunter]

Just finished my Goped ESR 750H 38V 37.5 amp 18650 battery pack. My goped weights about 35-40 pounds and I should get about 32-35 miles range per charge.

What speed controller are you going to use?

I would like to see a brushless conversion......

 

[Silenthunter]

Silviasol,

you should try 18650 cells. I only spent $215 for the cells ( 135 cells total battery - 9S with 37.5 Amp) plus maybe $15-$18 for the cooper strips and some heavy soldering work. I also think 18650 cells are much more reliable and safer.

 

[Guy H]

Just finished my Goped ESR 750H 38V 37.5 amp 18650 battery pack. My goped weights about 35-40 pounds and I should get about 32-35 miles range per charge.

What speed controller are you going to use?

I would like to see a brushless conversion......

Brushless?
wait few days for my hoverboard pictures

 

[silviasol]

Any update? A step by step walk through would be awesome!

I am thinking total range is about 40-50 miles in 20mph turbo. Weather got bad up here so it is still too cold to ride. I will be redoing the pack in a month or so to make it fit better in the pan, I will post pictures of the entire build.

Just finished my Goped ESR 750H 38V 37.5 amp 18650 battery pack. My goped weights about 35-40 pounds and I should get about 32-35 miles range per charge.

What speed controller are you going to use?

I would like to see a brushless conversion......

I would assume mine weighs 50-60 pounds. Did you post pictures of your 18650 pack? My current project is for an individually fused 18650 pack. I have the copper strips cut for a pack just need to figure out the fuse part. I figure I can fit about 50ah of the 2.9ah 18650 cells in the pan without a deck spacer which would look really sleek!

Currently I am using the stock controller. When I do the 18650 pack(on my non hoverboard esr750) I will use 8 series power and a brushless motor/controller.

Silviasol,

you should try 18650 cells. I only spent $215 for the cells ( 135 cells total battery - 9S with 37.5 Amp) plus maybe $15-$18 for the cooper strips and some heavy soldering work. I also think 18650 cells are much more reliable and safer.

They are safer but any lithium in my opinion is dangerous without a pcm/bms. Going to take my time to get this 18650 pack right, fuses, pcm/bms, possibly a custom fit carbon fiber battery pan.

 

[Silenthunter]

Guy H,
I have been enjoying my brushless for about 1 year already and it is awesome!
I can't wait to see your conversion. I wish I had the C80100 motor for the next goped conversion.

Silviasol,

I get 12 miles for each 13 amps which should bring me to around 33-34 miles range with 37.5amps. I have 15T and 80T with 27-28 miles/h.
At 20 miles/h you should of get a bit more but not as much as you expect.
My battery is 9S with 34V (I only charge to 3.95V because of Mamba XL 34V limitation) but I am thinking of upgrading to a more powerful ESC and add an extra cell (10S with 41V). I should get over 35miles/h so if I geared it down I should get @30 miles/h and gain some extra miles range.

I have been running 18650 for over 2 months and they don't even get warm. I discharged few cell up to 1.7V under load and the cells came back with no issues. I charge them up to 3.95V-4V and so far only used them up to 3.3V under load and 3.5V with no load. (Charger- Icharge 3010B 1000W).
I balance the pack once every week and so far no issues and the cells perform super well.

I am planning to get some safety equipment and torture, punch through, destroy, over charge and discharge just to see what will happen with cells. I am super confident that 18650 is the safest technology so far.

 

[Silenthunter]

front wiew....

 

[silviasol]

Do you have pics of your pack build?

 

[Silenthunter]

Yes, I wil take some pictures and make some videos....

 

[z50king]

What motor are you running? My stock black can gets about 25Wh per mile.... Ehh

 

[Silenthunter]

My Turnigy SK3 gives me between 1.13 - 1.3 Amps per mile.

 

[silviasol]

I am now redoing the pack to make is fit better in the pan and only use two pcm/bms placed where the charger board which I removed normally goes. 2x 20ah 7s packs. Almost done just need to redo the main terminal since I didn't make it long enough.

 

[z50king]

I would suggest putting some padding down under the batteries in the pan. Dirt will get into the pan and under the batteries. That can be bad with shaking

 

[silviasol]

I have the stock padding that came with it on the bottom. I put alot of viva paper towel stuffed around the battery which works well to soak up any vibrations. I also have it sealed tight so no dirt gets in.

 

[z50king]

That's good. I used the stuff you use to line tool box drawers. I wrapped the batteries in it

 

[silviasol]

That's good. I used the stuff you use to line tool box drawers. I wrapped the batteries in it

Nice, it looks like that is the same stuff that came stock. The cells are such a tight fit I can't even put much padding on the sides(maybe 4-5mm of space), I am just going to rely on them being held firmly in place.

 

[z50king]

Are you using a deck spacer?

 

[silviasol]

Are you using a deck spacer?

Yes, absolutely! I also have the thicker deck(meant for the lipo versions without the spacer) that is bored out above the battery section of the pan. Even with that I had to use some thick rubber tape to raise it up about 1/4". Now with just the cells, without the bms on top, I can use a normal deck and have about 3/8" of clearance from the cells to the deck. Going to put some putty on the top cell on my first ride to make sure I am not bottoming out the deck onto the cells when the deck warps over bumps and stuff.

 

[silviasol]

Finished. Going to take a test run then doing one more upgrade with just one pcm/bms.

 

[melodious]

Wow, that is a HUGE amount of watt/hours for a goped. I believe the highest configuration for a stock goped is 28ah.

So now that your battery setup is legit, are you going to keep the same motor and gearing or are you going to upgrade those as well? 40ah and only being 20mph max (that's a guess) sounds a bit...tame.