jonescg's E-max 110s lithium conversion

[jonescg]

So here is my build log for the E-max scooter. These E-Max 110 scooters came with glass mat - lead cells. About 100 kg worth of them. So embarrasingly heavy they would state the mass as AGM 12 V batteries: 25 kg (x4)

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I picked this one up from Patrick at Electric Autos. He's winding down this business so I picked it up as a glider for $1000. I bought 16 LiFePO4 GBS cells from EV Power. Rod also supplied these little balance bleeders which trim any cell to 3.5 V each. One for each cell top and that more or less covers high voltage cut-off.

silver Emax upgrade 003.jpg (131.72 KiB) Viewed 7810 times

Low voltage will be managed by a centralised BMS using 2.54 mm pitch connectors.

Will post more after I go to work...

[Rodney64]

Subscribed Chris, any more scooters left

[jonescg]

Yeah mate, he's still got the two Pottz and I were racing - they just need mirrors and a kick stand and they're good to license. They have 60 Ah 48 V packs from Voltron 1. He's also got a couple of the little scooters - you know, the 55-60 km/h ones.

So over the last few days I set about installing a charger permanently onboard the bike. The charge port sits under the seat, but you need to bring the charger with you and leave it on the ground while it charges.

silver Emax upgrade 006.jpg (91.1 KiB) Viewed 7943 times

I had one of these 7 A, 48 V chargers from the AEVA scooter (also up for grabs) so I swapped it for the 10 A off-board charger and mounted it up under the front battery cover, just behind the main control board. Before I could mount it though, I had to take a piece of sheet metal (1.6 mm stainless steel I had lying around) and make it fit inside the frame rails behind the forks. I'm holding it to the frame rails using 25 mm P-clamps. These are not easy to use in this application, but they worked. I then pumped 4 M5 Riv-nuts into the sheet for the charger to screw to. To my frustration, the IEC C16 plug (kettle lead) wouldn't fit behind the frame rail when plugged into the charger, so I had to go and buy one of the 90 degree ones.

Then I cut the lead and soldered a male IEC connector and mounted it up on the front panel. Now I can just plug a kettle lead in and the scooter will start charging. A full charge will take a little under 10 hours, but we rarely need it quicker. Best of all, the large Anderson under the seat still works, so if you needed a quicker charge, use two chargers

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silver Emax upgrade 005.jpg (133.76 KiB) Viewed 7943 times

The charger still has good airflow, as this is largely exposed to the wheel well.

Unfortunately the top of the fork tubes touches the stainless plate I held in place with the P clamps. It's not critical, but you struggle when you get to full lock - only really an issue when locking the steering on the bike. Otherwise it looks good and is pretty convenient.

I'm in the process of wiring up the balance leads which will be used for balancing and eventually, the low voltage cut-off feature on the BMS. The battery needs to be lowered into place as two half-packs, and the joining connector screwed down once they are in place. Hope to have these done tomorrow around lunch time.

[jonescg]

I think this might be the shortest build thread I ever do! The scooter is effectively done - all that's left to do is get it licensed.

Today I soldered the balance wires onto each half of the battery. 8 cells each, so I just used these 14-way Molex knock-offs which do a pretty good job.

Finished pack.jpg (78.1 KiB) Viewed 7750 times

LiFePO4 cells are funny. They can look like they're all over the place, but as long as they're over 3.35 V at rest, they're probably full. It makes battery management a PITA because voltage is such a poor indicator of state of charge. Still, I know it's full because I balanced the pack with the trusty BC168 charger.

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The battery is assembled into the bike as two half packs. Front half first, then the back half. I have to tape them up using some fairly strong tape as they aren't locked into place at this state. Kapton was overkill, but it's strong.

Half packs for assembly.jpg (137.11 KiB) Viewed 7750 times

I drop the front half in and push it all the way to the front. I then cut the cable ties on the wiring which goes down the side of the scooter as it tends to get in the way when lowering the second half in.

Second half to go in.jpg (113.97 KiB) Viewed 7750 times

The second half won't drop in unless you undo the screws holding controller compartment. All of the fairing screws have to come out so that it can shuffle up about 25 mm. This is just enough room to fit the rear half-pack through the gap and gently dropped into place. The screwdriver is my top tip for this stage

Top Tip for installation.jpg (152.18 KiB) Viewed 7750 times

Then after pushing it forwards about 10 mm and joining the two half packs, I go about attaching the main positive and negative leads to the final terminals. They're bent up a bit so they fit properly without fouling the cell top covers.

Re-cable tie the wiring down the side and plug it in for a top-up. So easy now!

On charge.jpg (124.13 KiB) Viewed 7750 times

I have to find the other battery cover to put across the top, and install a top box for Katherine to stow her helmet. But that's it - how to turn a lead sled into a viable scooter in 2 days! We get about 70 km range on a charge, and that's at full throttle everywhere you go. I will eventually get a BMS installed for low voltage limits, but for now we keep a pretty close eye on the state of charge. We never go further than 60 km in a day anyway.

Best of luck with your E-max lithium prescription!

Chris

[Scottydog]

nice, pointed a friend to this thread as I know someone with one, maybe they will part with? Could easily do the same mod!

[mistercrash]

I can't help but thinking how small and light a battery made of 18650 cells would be.

[Scottydog]

I can't help but thinking how small and light a battery made of 18650 cells would be.

would be half the weight. But for many the comfort level using them might be lacking.

[Hillhater]

And a similar pack size would need approx 300 cells !....
..that's at least 600 connections to make and keep secure !

[jonescg]

And would they come in at under 54 cents a watt hour? And take about 4 hours to assemble?

Sure, a lighter pack would be nice, but really, this scooter doesn't need 150 km range. My arse is sore after 25 km!

[Samd]

Love it.
What's the powerplant in those?
I'm intrigued as to the expected performance.

[jonescg]

It's got what looks to be a Golden Eagle 4000 W hub motor. It will do 70 km/h top speed, and if you dial up the Sevcon for more amps (hope to do that soon) you can get there in a hurry too. Quicker than most sedans to the other side of the intersection. I just fitted a top box and installed the covers. Time to get it licensed!

Oh, and I fueled up my Blackbird (Honda CBR1100) and it cost me $35. $35 I don't really have, so this scoot's gonna get some commuter time!

[mistercrash]

And would they come in at under 54 cents a watt hour? It's possible. And take about 4 hours to assemble? Definitely not.

Sure, a lighter pack would be nice, but really, this scooter doesn't need 150 km range. My arse is sore after 25 km! It's more a question of handling, these scooters handle so much better when lighter. Anyway, I was just thinking about it.

[jonescg]

Ironically I think it handles a bit worse The shock was set up for 100 kg of lead, so now that we've shed 65 kg, it's a pretty hard and high ride. I think I need to take some preload out But otherwise it handles okay. Being lighter it takes off like a scooter should.

Just put the top box on but I can't get it licensed until after we get back from Canada. Not enough time to deal with the bureaucracy.

[Samd]

Ha. I know nothing about swingarm spacing on motos, but I am assuming you could do something like put one of the 22kg Quanshuns on it for a few hundred bucks and have a pretty funny sleeper around town to cause a few grins at the lights...

[DarylMc]

Hi Chris
I have a question regarding the EMax
Does the single sided swingarm allow for tyre changes without removing the motor or do people generally remove the motor anyway?

Nice work by the way.
That's my kind of machine:)

[jonescg]

Hi Darryl!
Yes you can change the tyre without ever needing to take it off the swingarm. It uses an inner tube. Just undo the 12 allen key bolts and take the rim off - the tyre slides right off.

Hey we're back out at QR tomorrow with Voltron - call Warren and get everyone out for the day!

[Scottydog]

Jones what is the top speed with the 48V setup? My mate sounds keen to get the free roller and do the same as you did. While it might be tempting to go with 60V it could complicate with controller and other component issues. If the 48V can do 52 - 54 kph then it's livable.

[DarylMc]

Hi Chris
I was a bit slow getting organised and neither Warren or I could make it there.
The websites for the series and QLD Raceway are terrible.
Warren tells me the bike went down?
I hope it was still a good weekend and please make it loud and clear when you are coming back again.
Good chance I will be able to tee up some accommodation and a proper bed next time at the Aratula McMansion if you are interested.

[DarylMc]

If you get the chance check out this song.
https://www.youtube.com/watch?v=JGhoLcsr8GA
I don't think I've ever heard a song about scooters before.
Maybe someday I will be hearing a song about electric ones:)

[whereswally606]

What capacity gbs cells did you use jonesy

[jonescg]

GBS 60 Ah LiFePO4.

Oh, and I've put 1200 km on it in about 2 months

[whereswally606]

that sounds like what I need, my commute is 23 miles each way and I want to do that on the scooter in warmer weather.

I have a few issues with my build though. I can get hold of a sevcon controller size 2 gen four but I can not for love nor money find the dcf file particular to these proud eagle hub motors.

I have 2 emaxes with older proud eagle controllers (read no where near as good) and a spare 4kw hub to bench test. if I could find a bonafide dcf file for the motor Id pull the trigger on the controller and the programming tool.

[jonescg]

that sounds like what I need, my commute is 23 miles each way and I want to do that on the scooter in warmer weather.

I have a few issues with my build though. I can get hold of a sevcon controller size 2 gen four but I can not for love nor money find the dcf file particular to these proud eagle hub motors.

I have 2 emaxes with older proud eagle controllers (read no where near as good) and a spare 4kw hub to bench test. if I could find a bonafide dcf file for the motor Id pull the trigger on the controller and the programming tool.

Next time I get the PC with the file on it, I'll copy the one currently on my scooter for you.

[whereswally606]

Jonescg, you are an F£%king legend as the pommes would say.

[jonescg]

Hey! Just thought I'd bump this thread so anyone working on a scooter can benefit from my experiences in this thread. Putting an onboard charger up behind the wheel well is a winning idea - highly recommended.

Clocked up 4100 km since October last year. Winning