New battery for EV global 36 volt bike

[Robertinwc]

Hello all, my name is Robert, and I've got a 36 volt evglobal bike that I want to get back on the road. I also want to stay with the stock bike. I liked it many years ago with the SLA and thought the power was more than adequate.

I also want to keep the new battery in the original removable case. The inside dimensions are 12"x4"x4" and my thinking is that if I could get decent performance out of an SLA of those dimensions I should be able to find something lithium that wold be more than its equal.

I've done a lot of research on this site around the EV global bikes and I realize that many don't think highly of them, my desire is to make this bike work. I have a number of nos parts including a controller so I feel I can keep this bike going a long time.

I saw this recommendation "The lithium battery option is $180 range shipped from Hobbyking. It's two 18.5v batteries (5lbs) you hook in series for 37v (42.5v) & then you need a 36v cheapy chinese charger." And they provided a link to the battery here: http://www.hobbyking.com/hobbyking/store/__20837__ZIPPY_Flightmax_8000mAh_5S1P_30C_USA_Warehouse_.html

I have a couple questions. Since this was back in 2011 and battery technology has changed so much, would this still be a recommendation?

What would you do?

I was looking at this but not sure. http://lunacycle.com/batteries/packs/36v/36v-panasonic-13-6ah-bottle-battery/

The inside dimensions of the ebike battery case are 12.25" x 4" x 4". So this bottle should almost fit. According to the site it's 12.5" x 3.5" x 3.5". I would cut some foam to cushion and stabilize the battery. My plan is to cut a circular hole in the top of the case to allow the nose of the battery to project out slightly from the case since the battery is only slightly longer than the id of the case.

I confess I'm a bit out of my comfort zone and I was hoping you all wouldn't mind providing some guidance.

Thanks!

 

[skeetab5780]

I would personally consider removing the evg battery case. For one it eats up alot of space which could equate to more watthours. And second it has a pretty heavy built in SLA on board charger that will be useless. Furthermore the connection between the battery box and the controller runs thru a contact block which works but is not the best to be fair.

The case does have a pretty little handle that is cool. Thats the only good part.

You can get a pretty large 18650 pack from a random vendor like batteryspace.com that will be heat shrinked and strong enough to survive without the plastic EVG housing

 

[marcelo56]

http://www.electric-bike-kit.com/12v-lithium-lifepo4-replacement.aspx?gclid=CNK14bGVlMwCFVNZhgodc-cNqA

 

[Robertinwc]

Hey skeetab,

Thanks for your quick reply! i see what you're saying about the battery box, and here was my thinking. The bike is going to be stored in a 3 sided carport, like a garage but no door. So while it will be chained up, it will be exposed to passers by. So I want to be able to easily pull the battery out both for security and to recharge inside the house. So the case, with its handle and connection block seem like they would seem to be an asset in my circumstances.

I already took out the old charger from the top of the case, knowing it wouldn't work with the new battery. So that weight is gone. I also know I could get a bigger battery in the opening without the box, but I'm not sure I would need, or ever use, that much more battery. And that much more lithium has a price tag.

So that's why I've been thinking about finding something to fit inside the old case.

Does that sound reasonable?

 

[Robertinwc]

Marcelo thanks for the link. However the size on those don't seem to work. According to the site:
Dimensions: 5.94x2.55x3.74 in.

I'd need three in a 12x4x4 in space.

 

[dogman dan]

Best bet would be to have a custom size pack made from 185650 cells. EM3ev might be the one who can do it for you. Just give him the dimensions, and he may be able to help you out.

It's also possible that other batteries may be the same general size and shape, once you remove the battery from the stock box. So look also at the frame mount packs. One of those may fit in the EVG case.

Nothing wrong with keeping an EVG going, if you don't mind the motor noise. They were great bikes.

 

[dogman dan]

That's true, I bet the 36v allcell will fit in the original box. Or many other brands, in a 36v 10 ah size. It's a very small battery, a 36v 10 ah 18650 pack.

 

[skeetab5780]

This is what mine looks like. I have 20s 8ah 18650 Greenworks old cells they do ok. There is still more room to spare. Notice the nice hole in my frame

 

[Robertinwc]

Hello all,

Thanks for the guidance. I ordered this today from batteryspace: http://www.batteryspace.com/linimnco-battery-36v-15ah-540wh-30a-rate.aspx

It's made of 30pcs of LiNiMnCo 26650 5Ah cells. Cost was $400.

I went with batteryspace for two reasons. They seem trusted by this community and they are about a 30 minute drive from my house. They are going to have to build it, so if anyone thinks I've made a mistake let me know and I can probably change the order... If I act quickly.

I'm anticipating a nice change from the SLA 36v 8ah battery the bike came with originally. And like I posted previously I was happy with it!

Thoughts??

 

[gogo]

You should get 3X more miles out of that and less voltage sag. Unlike SLA's rugged plastic box, this is a 'bare' pack, so be careful not to dent the cells!

 

[Robertinwc]

Thanks for the comment! The extra range should be great. And the new battery (270 mm(10.6") x 84 mm(3.3") x 82 mm (3.2") is going to fit inside the evglobal rugged ( 12 x 4 x 4 ) battery box with its great handle. So it's going to be protected.

 

[Cephalotus]

Make a well designed battery pack with Sony US18650V or similar LiMn2O4 (LMO) cells.

10 in series, parellel as many as you like.

Include balancer cables to ckeck cell voltages once a year. Just in case.

Super cheap.

Super long life. Can last 500 full cycles or 10 years if charged only to 41V and not stored in the heat.

10 times as good as lead acid (but not the best available in energy and power densitiy, but you do not need that)

No electronic is needed.

 

[Robertinwc]

Thanks for the idea, but making a battery pack, particularly one "well designed" is beyond my knowledge. I don't know where I'd start, and if I were to figure it out my confidence level in it would be limited.

 

[dogman dan]

That will do er. Just pack it into the box, using some kind of relatively soft shim material to keep it from rattling inside the box.

I'm sure you know this, but you can't use the original charger anymore. But you can remove the original charger from the battery box, and wire your charge wires to that plug. Then put the matching plug on your new charger.

 

[Robertinwc]

You're right, I've already removed the existing charger, knowing it wouldn't work. I bought a 3amp charger from the same fellow who sold me the battery. I figure doing so would avoid any compatibility issues. I like the idea of making the old plug work with the new charger! The charger comes with a tamiya connector as standard and I was think of how I might be able to mount it flush to the outside of the box.

 

[Robertinwc]

Hi all,

Well I picked up my LiNiMnCo Battery 36V 15Ah 540Wh, 30A rate from batteryspace yesterday. (Nice people to deal with btw.). I've loaded it into the old evglobal battery case, using some styrofoam sheets I cut to fit the bottom, sides and a short filler in front. It actually fits this case about as perfect as could be, allowing for just enough room to add some cushioning.

I need to find some connectors from the battery leads to the battery box, and I assume I'd just use some spade or bullet crimp-on's unless someone has a better recommendation. These won't be used often as I shouldnt have any reason to take the battery out of the box.

Here's a pic:

 

[skeetab5780]

Nice battery space tends to have what people need for low power options. I always suggest that place. Glad it fits how does it perform?

 

[Robertinwc]

Good question! I haven't made the final connections in the battery box yet. It's raining here today, so I'll head over to radio shack to by some connectors in a bit. When that's done I'll put the lid on and be ready to go tomorrow, when we are supposed to have better weather.

 

[dogman dan]

Maybe your radio shack is better than mine, they did not have much in the way of a 30 amps connector.

But any car parts store will have the yellow spades, for a big wire. Those will do.

Best would be Anderson power poles, or one of the RC type connectors such as 4 mm bullets.

 

[skeetab5780]

Ya unfortunately my favorite lil nerd kid hobby store i grew up in(radio shack) is now just a useless cell phone store.

 

[Robertinwc]

You're right! Radio Shack was a total bust. So I went to Frys Electronics and found some yellow Nylon insulated 10-12 ga spade connectors. I went looking for the Anderson or bullets and couldn't find anything. There is no amp rating on these spade connectors, so I'm a little concerned. They're made by Installbay, who I've never heard of... But I'm thinking a 10-12 ga wire is going to have some current flowing so a connector that size should work. Hope I'm right!


So I made my connections and then put the charger on the new battery last night. It's a 3 amp charger, and it ran about 5 hrs before the green light came on. I'm ready to put the lid back on and go for a ride later when the weather is suppose to clear this afternoon.

Here's a pic