I think my scooter lead acid batteries died, I want to go with Lithium

[sgtkahuna117]

My scooter is a Yadea S-Like 2000w scooter it is limited to 60 km/h - 37 mph , but recently it lost all the performance, I charged it to 100% but the battery indicator would show 10% when riding, and the performance was very low compared to when the scooter was good.

I assumed it was the batteries, I removed them and I noticed it was using lead acid batteries, I thought they were lithium but they're not.

I'm looking to replace the batteries and go with Lithium now but I don't know anything about electric scooters.

I saw some on Aliexpress but it mentions 20 BMS or 50 MBS, not sure which one should I pick and if that requires configuration. The controller reads: "40±1A"

I took these pictures:





I need some help, please. What should I buy, where can I buy it? which BMS? etc.

Thanks!

 

[jetpackjbd]

Heyyy, I’m in the same situation! You see to have more battery space than I do which makes finding replacements easier. Don’t buy off aliexpress, they’re almost guaranteed to be trash. I’d suggest looking on batteryhookup.com, they’ve got great prices on good quality used batteries with great support and warranties. These might fight your needs but I’m not sure. Tenergy 12.8v 20ah 256wh Lifepo4 Battery with BMS

When looking at battery ratings, go based on the first number. You’ll usually see something like “Continuous Current”, and that’s what you should go by. MBS would be peak current, meaning the most in can handle for a few seconds such as during heavy acceleration.

 

[sgtkahuna117]

Heyyy, I’m in the same situation! You see to have more battery space than I do which makes finding replacements easier. Don’t buy off aliexpress, they’re almost guaranteed to be trash. I’d suggest looking on batteryhookup.com, they’ve got great prices on good quality used batteries with great support and warranties. These might fight your needs but I’m not sure. Tenergy 12.8v 20ah 256wh Lifepo4 Battery with BMS

I believe the new battery has to be 72v 20Ah

 

[jetpackjbd]

I believe the new battery has to be 72v 20Ah

Oh damn, you need 72V? I’m not sure if the battery I linked can support 6 in series, but if it does then it should be a drop in replacement. I’d contact their support to ask about it.
What are the dimensions on each battery? The battery I linked appears to be the same size but I’m not sure without any measurements.

 

[RunForTheHills]

Those are 12V SLA batteries in that scooter scooter. If you connect six 12V batteries in a series you get 72V output. Probably a little more when fully charged. It wouldn't be typical for all the batteries in a scooter to be connected in series though. More likely it is something like 2S3P for 24V output. You can check it with a multimeter or trace the cables to see how it is hooked up.

 

[jetpackjbd]

Those are 12V SLA batteries in that scooter scooter. If you connect six 12V batteries in a series you get 72V output. Probably a little more when fully charged. It wouldn't be typical for all the batteries in a scooter to be connected in series though. More likely it is something like 2S3P for 24V output. You can check it with a multimeter or trace the cables to see how it is hooked up.

For a 2000W scooter 72V sounds about right from what I’ve seen before. If you’ve got beefy batteries that can handle 20-30A each you should be fine with 6 in series. I’d expect a 12V 20AH LFP battery to handle that current.

An equivalent 24V system would draw over a hundred amps at that size motor and be pretty inefficient. I’ve got a 500W scooter that runs on 24V and powering it is a struggle, forget 2000W

 

[sgtkahuna117]

I was looking at these:

https://www.aliexpress.us/item/3256806086943925.html?gatewayAdapt=glo2usa

https://www.aliexpress.us/item/2251832847945217.html?gatewayAdapt=glo2usa

https://www.aliexpress.us/item/3256806224471758.html?pdp_npi=4%40dis%21USD%21US%20%24646.07%21US%20%24516.86%21%21%214634.62%213707.70%21%402101ef8717075000537584454ef6d2%2112000037067803768%21sh%21US%211700822749%21&spm=a2g0o.store_pc_allItems_or_groupList.new_all_items_2007567550998.1005006410786510&gatewayAdapt=glo2usa

 

[jetpackjbd]

I was looking at these:

https://www.aliexpress.us/item/3256806086943925.html?gatewayAdapt=glo2usa

https://www.aliexpress.us/item/2251832847945217.html?gatewayAdapt=glo2usa

https://www.aliexpress.us/item/3256806224471758.html?pdp_npi=4%40dis%21USD%21US%20%24646.07%21US%20%24516.86%21%21%214634.62%213707.70%21%402101ef8717075000537584454ef6d2%2112000037067803768%21sh%21US%211700822749%21&spm=a2g0o.store_pc_allItems_or_groupList.new_all_items_2007567550998.1005006410786510&gatewayAdapt=glo2usa

Ehhh, the prices seem right but I still wouldn’t trust aliexpress.
The first one is a Lithium Polymer battery, which can handle more power in a smaller size, but don’t have a very long lifespan. They’re also the most fire-hazardous of the battery chemistries. Not sure if the ratings are correct though, it seems a bit too small for 72V 20AH.

The second two are Lithium Iron Phosphate, which have the greatest lifespan but doesn’t store nor output as much power in the same size. Not sure if these would fit in your scooter given their big blocky shape.

Again, I’d look elsewhere. You should be able to find similar prices on more reputable sites. Feel free to take the gamble though, it’s possible you’ll get a great deal. But you never know.
I believe Neptronix made this:

Keep in mind too that you’ll have to replace your charger with something compatible with your new battery chemistry, since lead-acid chargers will kill lithium batteries over time and don’t have the same exact voltages.

 

[sgtkahuna117]

Ehhh, the prices seem right but I still wouldn’t trust aliexpress.
The first one is a Lithium Polymer battery, which can handle more power in a smaller size, but don’t have a very long lifespan. They’re also the most fire-hazardous of the battery chemistries. Not sure if the ratings are correct though, it seems a bit too small for 72V 20AH.

The second two are Lithium Iron Phosphate, which have the greatest lifespan but doesn’t store nor output as much power in the same size. Not sure if these would fit in your scooter given their big blocky shape.

Again, I’d look elsewhere. You should be able to find similar prices on more reputable sites. Feel free to take the gamble though, it’s possible you’ll get a great deal. But you never know.
I believe Neptronix made this:
View attachment 347311
Keep in mind too that you’ll have to replace your charger with something compatible with your new battery chemistry, since lead-acid chargers will kill lithium batteries over time and don’t have the same exact voltages.

What other sites can I find these types of batteries at good prices? I couldn't find anything similar at Genuine Lithium Batteries for DIY Projects

Where I live we have many hills and my scooter struggles with those I believe its because of the lead acid batteries, which chemistry would be better having that in mind?

 

[jetpackjbd]

What other sites can I find these types of batteries at good prices? I couldn't find anything similar at Genuine Lithium Batteries for DIY Projects

Where I live we have many hills and my scooter struggles with those I believe its because of the lead acid batteries, which chemistry would be better having that in mind?

I would just look on Google and search through multiple sites, don’t check just one site.
Any chemistry should be ok, but if you’ll be going up big hills frequently than you’ll probably want something rated for 30A continuous instead of 20 or 30A.

I found this which is a bit expensive but would be perfect for your application, assuming it fits inside your scooter.

76V 20ah Li-ion Battery

This Eon Lithium 76v Li-ion 20ah Battery fits into a variety of small bikes such as the Razor MX series. With a 150amp discharge rating you will be sure to get that next level punch you need for your light weight mini moto. This is our most popular pack in the lineup as it packs an incredible...

electroandcompany.com

 

[999zip999]

I never bought from this company but it sure looks good as it's printed. ???

BtrPower Ebike Battery 72V 30AH LiFePO4 Battery Pack with 5A Charger 5

72V 30AH LiFePO4 Battery can work well for 350W-3000W motor. Quality Cell. BtrPower battery is approved by UL. LiFePO4 battery is more stable and safer than li-ion .Never catch fire.you can use it safely Endurance Mileage: it can up to 45 miles and it’s affected by factors such as load bearing...

www.btrpower.com

I'd also like to try to get some feedback from this forum on this battery site that's another reason I'm throwing this up here. I'm not recommending this because I haven't bought one.
Venezuela I wonder what your import policies are in shipping ?

 

[jetpackjbd]

I never bought from this company but it sure looks good as it's printed. ???

BtrPower Ebike Battery 72V 30AH LiFePO4 Battery Pack with 5A Charger 5

72V 30AH LiFePO4 Battery can work well for 350W-3000W motor. Quality Cell. BtrPower battery is approved by UL. LiFePO4 battery is more stable and safer than li-ion .Never catch fire.you can use it safely Endurance Mileage: it can up to 45 miles and it’s affected by factors such as load bearing...

www.btrpower.com

I'd also like to try to get some feedback from this forum on this battery site that's another reason I'm throwing this up here. I'm not recommending this because I haven't bought one.
Venezuela I wonder what your import policies are in shipping ?

I’m reading mixed reviews on their battery quality but they’ve got good support apparently. Not sure about shipping to Venezuela but if they’re willing to ship from the UK to the US I’d imagine it’s not much different to go further south. Maybe they’ll need someone from the US to smuggle it across the border

 

[E-Moto Tuner]

One or two of your lead acid batteries are likely done and bringing down the rest of the pack. I just had this with my lead acids, one of the six went bad. Replaced it and all is well again.

For lithium, I would try the local dealers/stores first - more $$ but easier to exchange if there's a problem. Ali-express, or another Chinese sourced will be cheaper but hit and miss as some sellers are reliable and others not so its best to get others opinions on who they used if they had a good experience. I get most of my parts (not batteries so far) from Chinese sellers as they made most of the bikes over there in the first place. I also get some from a certain local dealer when I can as they don't up charge too much like all the other local stores in my city.

 

[999zip999]

It's a Chinese company that has a warehouse in USA and a warehouse in the UK. That's the way I read the sells pitch. That's one of the reasons it got my curiosity up but I'll read it again they just have a couple days shipping in the US.
It said three to five shipping days for the USA and that means they will ship it in 3 to 5 days or I get it in 3 to 5 days ??
Did I read this wrong I thought they had a Us warehouse. Will they USA Warehouse it seems like they have to have certifications and stand behind their product more at least you could go and punch him in the nose.

Destinations​

We only ship orders to Continental US.

Currently we DO NOT ship to Alaska, Hawaii, and Puerto Rico.

All our products are ship from US warehouse.

Shipping fee​

• FREE shipping on all orders
• Shipping method: FedEx Ground

Shipping time​

 

[sgtkahuna117]

One or two of your lead acid batteries are likely done and bringing down the rest of the pack. I just had this with my lead acids, one of the six went bad. Replaced it and all is well again.

For lithium, I would try the local dealers/stores first - more $$ but easier to exchange if there's a problem. Ali-express, or another Chinese sourced will be cheaper but hit and miss as some sellers are reliable and others not so its best to get others opinions on who they used if they had a good experience. I get most of my parts (not batteries so far) from Chinese sellers as they made most of the bikes over there in the first place. I also get some from a certain local dealer when I can as they don't up charge too much like all the other local stores in my city.

How can I test which one is bad?

 

[amberwolf]

What are the voltages of each one when the problem occurs?

How old are the batteries?

If they're all the same age, they're probably all in nearly the same condition, so any that haven't failed yet may soon do so.

It's usually a safer bet to replace the entire pack at once, with identical good-quality batteries that are more than capable of meeting the demands of your system.

The controller says it's 40+/-1A, so any battery you use has to be able to supply *at least* 41A. The more it *can* supply than that when new, the better it will still perform as it ages, and the less voltage sag it will have under just the load it sees in your usage, so the more power you get to the wheel, and the better overall performance it has. Even range is improved because it sags less when it gets close to empty so you can go farther at a higher power level without backing off on the throttle just to prevent shutdowns.

The batteries you already have in there appear to be a standard shape, in series to give you 72v--that takes 6 12v batteries, whcih charge up to nearly 85v full, so any liithium 72v pack that charges to 84v full would be similar voltage.

They're 20Ah, but with lead-acid you really only get about half the capacity when using it in an EV type application, where you should get much closer to rated capacity with lithium.

However, not all lithium cells can provide as much current as lead, so you have to get ones that are capable of at least that 41A your controller may draw, without being pushed to their limits to do it. (otherwise they may not perform any better than the lead, or be worse).

LiFePO4 are the most common type to see built into cases that fit where your lead does. But you may need ones with no BMS to be able to series them for the voltage you need, unless they specifically state they'll work seriesed up to the 84V+ that you'd need. LFP usually is capable of about the same current as it is capacity, or sometimes doulbe that. So a 20Ah battery usually supplies at most 20-40A. Meaning, you might not be able to run the scooter at full performance, if the battery isn't capable of >40A.

You may find other Li types in those cases too, and they may be more capable than the LFP is.


Because Li is so much "better" performing than lead for it's size/weight, it *might* be possible to find a non-LFP Li battery that is 72v and high enough Ah and capable of enough A that will fit in the space where just those three top batteries are. If not, you may find two you can parallel, one in the top space, and one in the bottom. These wouldn't be shaped like the lead ones, but they would functionally do the same job.

If you have to parallel two, you must get BMSes in them that are "single port" or "common port" that charge and discharge from the same wires. I'd recommend this in any case, but it's more common to find "dual port" that have separate sets of wires. (it's not just the wires, the BMS are functionally different, and have to be built to protect the battery in this specific situation).


So, all said, you can probably get a non-LFP type Li battery that's 72v (84v-ish full) and at least 20Ah, capable of at least 41A, to run your scooter, in a number of ways.


I don't recommend buying anything off ebay, aliexpress, amazon, etc., for batteries. I'd recommend locating a local reputable battery seller, and if there isn't one, then at least a reputable seller close enough to you that you can work with them if you have problems with the batteries.

 

[sgtkahuna117]

I'm unable to read the voltage while running the motorcycle

 

[Zambam]

My scooter is a Yadea S-Like 2000w scooter it is limited to 60 km/h - 37 mph , but recently it lost all the performance, I charged it to 100% but the battery indicator would show 10% when riding, and the performance was very low compared to when the scooter was good.

I assumed it was the batteries, I removed them and I noticed it was using lead acid batteries, I thought they were lithium but they're not.

I'm looking to replace the batteries and go with Lithium now but I don't know anything about electric scooters.

I saw some on Aliexpress but it mentions 20 BMS or 50 MBS, not sure which one should I pick and if that requires configuration. The controller reads: "40±1A"

I took these pictures:

View attachment 347272

View attachment 347275

I need some help, please. What should I buy, where can I buy it? which BMS? etc.

Thanks!

My 1500 watt Fly 7 scooter has 3,000 Km on the odometer & still running on its 60 V 20 AH lead acid batteries. How many miles/ kilometers before your's died. I am looking to replace the lead acid when they die and would be interested in what you find as a replacement.

 

[sgtkahuna117]

My 1500 watt Fly 7 scooter has 3,000 Km on the odometer & still running on its 60 V 20 AH lead acid batteries. How many miles/ kilometers before your's died. I am looking to replace the lead acid when they die and would be interested in what you find as a replacement.

If I recall correctly, about 2,700 km

 

[Zambam]

If I recall correctly, about 2,700 km

Did you ride it easy or hard? I ran mine on level 2 (of 3 power levels), rarely use full throttle, always gently accelerate and kept the battery fully charged. Wonder how much longer my SLA's will last.

 

[sgtkahuna117]

Did you ride it easy or hard? I ran mine on level 2 (of 3 power levels), rarely use full throttle, always gently accelerate and kept the battery fully charged. Wonder how much longer my SLA's will last.

Mine only have eco and sport, I always use sport it only goes up to 60km/h

 

[Zambam]

Mine only have eco and sport, I always use sport it only goes up to 60km/h

Mine goes up to 60 km/hr also. In your first pic, I see only 5 batteries. Is there one more mounted elsewhere to make it 72 V?

 

[E-Moto Tuner]

How can I test which one is bad?

I did a full charge then rode about 10 minutes to get the batteries under load, then checked each battery with a multimeter to get the voltage of each. Bad one/s will drop off quite a bit more than the rest after being under load. I also picked up a cheap $20 digital battery tester later from Ali-express which confirmed the one that needed replacement as when I tested the one I changed out it showed "replace".

My bike has a similar setup to you (37a 72v controller and same 20ah batteries). Most in my area replace with a 72v 20ah or 30ah lithium for my style of bike (Honda Grom clone).

 

[Zambam]

I never bought from this company but it sure looks good as it's printed. ???

BtrPower Ebike Battery 72V 30AH LiFePO4 Battery Pack with 5A Charger 5

72V 30AH LiFePO4 Battery can work well for 350W-3000W motor. Quality Cell. BtrPower battery is approved by UL. LiFePO4 battery is more stable and safer than li-ion .Never catch fire.you can use it safely Endurance Mileage: it can up to 45 miles and it’s affected by factors such as load bearing...

www.btrpower.com

I'd also like to try to get some feedback from this forum on this battery site that's another reason I'm throwing this up here. I'm not recommending this because I haven't bought one.
Venezuela I wonder what your import policies are in shipping ?

Looking to replace 60V 20 AH lead acid battery

I bought my Fly 7 moped new in Dec 2021 and have since put 1800 miles on its 60 V 20 AH lead acid battery. I took these measurements today: Fully charged 66.5 V. @ full throttle it sags down to 55 V with a draw of around 34 amps per my clamp ammeter. Does that sound typical for a 3 year old...

endless-sphere.com

 

[Chalo]

I never bought from this company but it sure looks good as it's printed. ???

BtrPower Ebike Battery 72V 30AH LiFePO4 Battery Pack with 5A Charger 5

72V 30AH LiFePO4 Battery can work well for 350W-3000W motor. Quality Cell. BtrPower battery is approved by UL. LiFePO4 battery is more stable and safer than li-ion .Never catch fire.you can use it safely Endurance Mileage: it can up to 45 miles and it’s affected by factors such as load bearing...

www.btrpower.com

Pedicabbers often use those packs, usually in even larger capacities. The BMSes are cheap and somewhat failure prone, but (relatively) easy to replace as needed. But when cells fail as they sometimes do-- maybe from defects, maybe from physical damage, maybe from failed BMS-- the packs are generally not worth fixing because all the pouch cells are glued together into an inseparable lump. Individual replacement cells have never been available when I looked for them.

It's plausible to jumper over the bunk cell(s) and run at a lower voltage, but that requires both BMS and charger be replaced. For probably USD $700-800 shipped, I'd want a battery that responds to repair efforts better than that.