Citycoco disaster

I recently acquired this old scooter from a friend.
A little about me, I know my way around a combustion engine, but know close to nothing about electric. I have a lot of experience on a soldering iron (built my own box mods, as well added LEDs to my motorcycle). I tend to take on projects that are at first over my head, but with a little research I can make due. I feel as though now I have a basic understanding on how electric engines are driven and powered but I don't trust certain websites to have the correct hardware that I am looking for. I do have the confidence to build my own battery. Though I have never used a spot welder, it looks extremely simple.

The things I am stuck on: (basically everything)

I believe my motor is in good shape, so I will reuse. I also believe that it is a 1000w hub motor

I don't know if the controller is good or not. I don't really care though because I'd like to upgrade to be able to set the parameters of the battery output.

I do believe that my battery is bad though. If I'm not mistaken it is a 16 series 7 parallel 18650 battery pack. Not sure about the BMS, or even if there is one.

The things I'd like to accomplish:
I'd like to have a working system and be able to go about 20-25 mph. If I cannot with this 1000w motor... So be it.
Would it be better for me to buy a battery instead of building one?
I'm hesitant to pull the trigger on anything from anywhere because I don't know what sites I can trust.
I'd like to be able to get something for this battery. Is there somewhere I could return the cells and get a discount on new cells?
I have some pictures below, any input is much appreciated. I'm not really looking to move forward until I have the necessary knowledge to do so. (Not trying to spend more than I have to)
-thanks, CJ

ceejemeister said:

I do believe that my battery is bad though.

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Test don't guess. If you don't have one? Get a multimeter.

What I would do. Put it all together. Charge battery. See if it works. If it's not broke? Don't fix it.

Like the PINK fenders. Or is that PURPLE?

ceejemeister said:

Is there somewhere I could return the cells

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As far as I know unless you have a boat or train load of batteries, they have no value. Take old batteries to Home Depot for recycling. Or check your local garbage / recycling rules.

Old batteries have no trade-in value and are considered hazardous waste in most places.

Reputable sources of cells -

Buy a $10 volt-ohm meter and check your existing pack before doing anything. It's the most expensive thing that you have there. Your EVE cells are rated at 2550mah.

Diggs said:

$10 volt-ohm meter

Click to expand...

Na...... buy the best tools you can afford.
Money saving idea? Check warranty at fluke.com. Buy a used Fluke multimeter on eBay. If it's broke? Think Fluke will repair or replace.

marty said:

Na...... buy the best tools you can afford.

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A cheap one is better than nothing and today's cheapest are more accurate than 1/2 the stuff I grew up with. Yes, I have a Fluke on the bench in the basement but cheapies in the garage, van and backpack.

You sure have a bms, it is the thing the red wires go to. The cells are from a good chinese manufacturer, they can very well be worth to use if they are in good shape. Try googling the markings and see what you can find about specifications.
Edit, ok these are 2550mAh 7,5A cells.. Not much fun if you want performance

marty said:

Test don't guess. If you don't have one? Get a multimeter.

What I would do. Put it all together. Charge battery. See if it works. If it's not broke? Don't fix it.

Like the PINK fenders. Or is that PURPLE?

Click to expand...

I have tested it. The whole system reads 8.17 volts from the positive and negative sides of the nickel leads
Thought the wires that lead to the charger it reads 8.10.
That means I have a drop of .07 through the BMS, correct?
Also. No charger.

Diggs said:

Old batteries have no trade-in value and are considered hazardous waste in most places.

Reputable sources of cells -

https://batteryhookup.com/

18650 Battery Store - Trusted Supplier of Lithium Ion Batteries

18650 Batteries | 18650 Chargers | 18650 Accessories | Discover a wide selection of high-quality 18650 batteries and accessories at 18650 Battery Store. Shop with confidence knowing you'll find top brands, exceptional performance, and competitive prices.

www.18650batterystore.com

Buy a $10 volt-ohm meter and check your existing pack before doing anything. It's the most expensive thing that you have there. Your EVE cells are rated at 2550mah.

Click to expand...

Thanks diggs, made an account gonna grab 150 18650 batteries. For the 60v 20ah battery I'm going to build, got some nickel fuse, and I can pick up wire at my local electronics store(going to stick with the same gauge that was used on thr previous battery. The couple things I'm curious about, once I complete my battery, how will I know if I shorted a cell during construction? I can't just charge it with any old charger, will I have to build a charger as well? If I decide to put more amp hours into the battery and have another row parallel, will that affect the choice of my BMS? What BMS do I go with? Once decided on the BMS, how do I test the entire system ( I don't have the high tech device to show which group is good and bad, and what voltage they are at. Also, not sure of what controller would be best for my system.

And at the very end, I am going to need a screen and throttle ( I'm not using the one on there)

I know I said I don't want to spend a lot on this, but making my own battery will save me upwards of 100. And I know the cells will be good. I also don't want cheap things in the system, or to mickey mouse the build. This will be used by my family. And trying to make it pretty cool.

Sorry for the list of questions. If there is instead a website I can learn these things from, please don't hesitate to guide me there.

As for an update, can't really proceed. Just took apart the motor and gave it a clean. Magnets were lightly coated with debris of some sort. Hit it with some rust remover and reassembled.

Have you a reliable battery spot welder? The cost of it and it's power supply, let alone the learning curve, makes a build your own battery for a one-off deal quite expensive.
Battery building is a superpower, though it seems that we battery builders might soon become outlaws.

Actually, a decent spot welder for battery assembly can be had pretty cheap. The one I use can be had both on Amazon or Aliexpress. Depends on how much you want to pay and how fast you want it. It works great! Just don't skimp on a battery to power it. Use a car battery. (Many YouTube demos. It has been improved in several ways since the early versions.) There are also quite a few YouTube videos on battery construction.

You can add another cell in each group (8p) if the bigger pack will fit in the scooter. No need to build a charger as 60v chargers are relatively inexpensive and available on Amazon/Ebay/Aliexpress.

Building a battery is tedious. All cells need to be set at the same voltage. Cells should be tested, sorted and the 16 groups should have the all have the same mah total of battery capacity. I cycle all my new/used cells first with a Lii-500. It's not the most accurate but good enough to rank all my cells against each other allowing me to build equal parallel groups.

You got 8.17 volts when testing between the far right and far left single nickle strip on the battery pack you pictured above? That's basically dead. Once a Li cell goes that low it shouldn't be used. Your cells may be gone but the BMS may still be good. Can't say for sure.

Then there is the red balance wires. They go on the positive (+) end of each parallel group. When you build your own they are usually soldered. Do you have a soldering iron/solder/flux and the skills/procedures to make good solder joints?

To make a long story short. Watch some battery building YouTube videos. It' a bit more involved than it looks.

I actually watched this entire video. It’s very detailed.


Still, I’m not building a battery. It’s just too dangerous and expensive to just build one pack.

gromike said:

Have you a reliable battery spot welder? The cost of it and it's power supply, let alone the learning curve, makes a build your own battery for a one-off deal quite expensive.
Battery building is a superpower, though it seems that we battery builders might soon become outlaws.

Click to expand...

Thank you Mike, though I do believe there will be a learning curve for this project, I have the utmost confidence in my ability. I also believe that buying a reliable spot welder and making my battery with a BMS, some .15 nickel strip, a couple waterproof connectors, and some outer battery protection would be cheaper than buying one that is AS reliable as the one I can make.

If you're saying that I am wrong, can you point me in the direction of a reliable battery with cells that that I know will all individually have the same voltage (or close) ?

The spot welder I'm thinking of getting would be the docreate 2.7v 3000f model, it's 130$ on Amazon.

Diggs said:

Actually, a decent spot welder for battery assembly can be had pretty cheap. The one I use can be had both on Amazon or Aliexpress. Depends on how much you want to pay and how fast you want it. It works great! Just don't skimp on a battery to power it. Use a car battery. (Many YouTube demos. It has been improved in several ways since the early versions.) There are also quite a few YouTube videos on battery construction.

You can add another cell in each group (8p) if the bigger pack will fit in the scooter. No need to build a charger as 60v chargers are relatively inexpensive and available on Amazon/Ebay/Aliexpress.

Building a battery is tedious. All cells need to be set at the same voltage. Cells should be tested, sorted and the 16 groups should have the all have the same mah total of battery capacity. I cycle all my new/used cells first with a Lii-500. It's not the most accurate but good enough to rank all my cells against each other allowing me to build equal parallel groups.

You got 8.17 volts when testing between the far right and far left single nickle strip on the battery pack you pictured above? That's basically dead. Once a Li cell goes that low it shouldn't be used. Your cells may be gone but the BMS may still be good. Can't say for sure.

Then there is the red balance wires. They go on the positive (+) end of each parallel group. When you build your own they are usually soldered. Do you have a soldering iron/solder/flux and the skills/procedures to make good solder joints?

To make a long story short. Watch some battery building YouTube videos. It' a bit more involved than it looks.

Click to expand...

The spot welder your talking about is a little advanced for me, I think the setup of that for this one project would be too much. I have seen someone use the docreate 2.7v 3000f spot welder, and that seems more my level. If I do end up getting more into electrical battery work then I will upgrade later.
That brings me to a great point! I don't have the Lii-500 or any kind of tool to rank batteries, can I use a multimeter to rank by voltage?
Yeah, I figured. it is much below half it's original voltage. I don't want to put it together with the old BMS just to find out that it didn't work. Better to cover all my bases and get a new BMS
I do have the soldering skills and resources, for those balance wires.
For the past 10 days I've probably logged about 8 hours a day watching every kind of battery building video, controller limits blah blah blah.
I still can't grasp what kind of BMS I'm looking for and as well, what kind of controller. I don't want to just use what was in the original bike

Thank you diggs!!!!!

slaphappygamer said:

I actually watched this entire video. It’s very detailed.

Still, I’m not building a battery. It’s just too dangerous and expensive to just build one pack.

Click to expand...

Thanks dude! I've watched this video a long with others from this guy. Much appreciated