# Did I select the correct battery for my 24V scooter?



## WCRiot (Nov 25, 2007)

Hello all
I am a bit of a newbie with the DIY electric vehicle stuff but am very mechanical and capable.
I have a Blade Z scooter running the SLA batteries that came with it. As a learning project, I want to replace these batteries. The Blade Z runs qty. 2, 12Volt 5Ah batteries in series. I wanted to build my own battery purchasing individual cells, as i have resistance welders and soldering irons at my disposal, but it seems cost preventive.

I found this battery as an option that would fit. Voltage is about right and 5Ah is a match.
Polymer Li-Ion Battery: 25.9V 5Ah (129.5Wh, 9A rate) Rechargeable Battery Pack
http://www.batteryspace.com/polymer...29-5wh-9a-rate-rechargeable-battery-pack.aspx

I was going to purchase their recommended charger for it as well.

Is this an equivalent option that would work? 
Why would i want terminals for "Charge" and "Discharge"? Do the discharge wires go to the electric Motor? or is that a separate function all together.


----------



## Yabert (Feb 7, 2010)

WCRiot said:


> Is this an equivalent option that would work?


Yes, almost every 6S lipo battery builded for hobby airplane could do the job (hobbyking as example).
And at 60$ to 100$ for a 5Ah to 10Ah battery that will give you extra money to buy a good balancing charger.


----------



## WCRiot (Nov 25, 2007)

Yabert said:


> Yes, almost every 6S lipo battery builded for hobby airplane could do the job (hobbyking as example).
> And at 60$ to 100$ for a 5Ah to 10Ah battery that will give you extra money to buy a good balancing charger.


What does the 6S mean? is that the size?

I looked into Hobbyking. They do have a 5Ah battery for about $80.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11941

Could someone still explain to me what the Charge and discharge wires are for from the first Battery i posted?


----------



## dougingraham (Jul 26, 2011)

WCRiot said:


> Why would i want terminals for "Charge" and "Discharge"? Do the discharge wires go to the electric Motor? or is that a separate function all together.


In this case of this battery module there is a circuit board that does the BMS thing for you connected to the charge and discharge wires. They try to prevent you from hurting the battery. You must use the charging wires when charging and the discharging wires when discharging with this setup. The spec sheet indicates a 9 amp poly fuse is in the discharge circuit so you would be limited to 9 amps. And 9 amps times 25.9 volts is 233 watts or 0.3 HP. I suspect you will trip the poly fuse all the time so this battery is not really appropriate for your application.

If you want to replace your battery I would go with a 6S (means 6 cells in series which gives a nominal 22.2 volts and a peak voltage of 25.2). And I would select about a 10 to 15 AH pack. This will give you about the same displacement and mass as the original lead acid battery. But for several reasons it will take you at least 4 times as far, possibly as much as 6 times as far. If you choose a 5AH pack you will get about twice the range but at a reduced size and weight of pack.

Good luck!


----------



## WCRiot (Nov 25, 2007)

dougingraham said:


> In this case of this battery module there is a circuit board that does the BMS thing for you connected to the charge and discharge wires. They try to prevent you from hurting the battery. You must use the charging wires when charging and the discharging wires when discharging with this setup. The spec sheet indicates a 9 amp poly fuse is in the discharge circuit so you would be limited to 9 amps. And 9 amps times 25.9 volts is 233 watts or 0.3 HP. I suspect you will trip the poly fuse all the time so this battery is not really appropriate for your application.
> 
> If you want to replace your battery I would go with a 6S (means 6 cells in series which gives a nominal 22.2 volts and a peak voltage of 25.2). And I would select about a 10 to 15 AH pack. This will give you about the same displacement and mass as the original lead acid battery. But for several reasons it will take you at least 4 times as far, possibly as much as 6 times as far. If you choose a 5AH pack you will get about twice the range but at a reduced size and weight of pack.
> 
> Good luck!


Doug
Thanks for the detailed reply.
I am not concerned about range. I use this scooter indoors at our manufacturing facility. I just need to get around here for a day at a time. I will charge overnight. I'm sure there would be goofing off time with that. But 5-10 mins of battery life per day would be sufficient. 

So the discharge wires basically go tot he motor right? That is why you suspect i would trip the fuse often?
What are your thoughts on the battery from Hobbyking that i posted a link for? It's nice and compact but I am concerned it would handle the constant load.


----------



## samwichse (Jan 28, 2012)

BTW, I had an old Razor (Pocket Mod) scooter I replaced the 24v lead with 36v (also lead, unfortunately)... the controller took the 50% overvolt just fine and bumped the top speed up significantly. It seems like a lot of these scooter companies sell separate 24 and 36v products that use the same controllers.


----------



## WCRiot (Nov 25, 2007)

samwichse said:


> BTW, I had an old Razor (Pocket Mod) scooter I replaced the 24v lead with 36v (also lead, unfortunately)... the controller took the 50% overvolt just fine and bumped the top speed up significantly. It seems like a lot of these scooter companies sell separate 24 and 36v products that use the same controllers.


That is excellent info. and I would really prefer to bump up the power. Mo POWA!!!!


----------



## dougingraham (Jul 26, 2011)

WCRiot said:


> So the discharge wires basically go tot he motor right?


No, they go to the motor controller.



WCRiot said:


> That is why you suspect i would trip the fuse often?


I am guessing that under normal circumstances you pull more than 9 amps at startup. However I could be completely wrong about that. It depends on things I don't know the answer to and you probably dont either. For example, what is the peak battery current? We can estimate it if you can tell me how long can you drive it around without stopping before it needs recharging?



WCRiot said:


> What are your thoughts on the battery from Hobbyking that i posted a link for? It's nice and compact but I am concerned it would handle the constant load.


I think that pack is way overkill for what you need. That pack is capable of doing 150 amps and is perfectly happy if you were to fully discharge it in 2.4 minutes. This would be 4.5 hp of drain. I am guessing you are looking at having to go 30 to 40 mph to get that kind of load.

Let me look at a less expensive HK pack. This looks like the least expensive one HK sells. 5AH LiPo Pack

There is nothing at all wrong with these packs. It can do 100 amps continuous. I am guessing you need an average of something less than 10 amps. If your average is 10 amps you could drive for 30 minutes. I mentioned a larger pack and the largest they sell as a 6S would be this:

10AH LiPo Pack

This would double your range vs the 5AH pack. In either case you will see a little higher speeds and more range.


----------



## WCRiot (Nov 25, 2007)

I ordered the 1010P charger and a 24V 5000Mah battery.
I'm gonna use a power supply I have laying around for now. I will reply back once everything comes in and I can test it.


----------



## WCRiot (Nov 25, 2007)

dougingraham said:


> No, they go to the motor controller.
> 
> 
> 
> ...


Guys
I just want to publicly thank Doug for all his help. He and I have been private messaging. He has guided me and is spoon feeding me.
He's been a great help and is definitely a star on this forum.


----------



## Sunking (Aug 10, 2009)

WCRIOT Rc batteries are kind of a niche product/ IO am am RC pilot of 40 year so I have quire a bit of experience with them. 

Really good LiPo packs get 200 to 300 cycles. Cheap one like HK considerable less. LiPo Watt Hour are still high, have come down some but still high compared to LiFePo4. Why RC pilots and modelers pay so much for them is the extreme Discharge rates of 30 to 100C. To put that into perspective discharged in 30 seconds to 5 minutes or less. We have to sacrifice cycle life and value for extreme performance. 

In a electric powered vehicle, unless you are a drag racer, you do not need that performance. Having said that for an ebike the expense of a Lipo is not extreme at $100 to $300 if you are OK with short cycle life. About the same as AGM, but no where near LiFePO4 of 1000 cycles. It is all about trade-offs.


----------



## piotrsko (Dec 9, 2007)

And if your cycles aren't rc model severe, the cells last longer.


----------



## WCRiot (Nov 25, 2007)

Hey guys
I'm back at it. I bought another identical scooter that the current Lead Acid batteries were shot. 

This time, I am replacing the motor, the controller and the batteries. If i have to build a customer motor mount, I will.

I bought a 48Volt, 1,000Watt motor/controller setup. I am planning on running at least two batteries in series as power. I might even run a third battery if it makes sense to go that route. These LiPo batteries are small enough to fit inside the scooters, battery area.

Do you guys suggest I go with a pair of the 22.2Volt 10,000Mah batteries from Hobbyking? Something like this one that was previously suggested:
http://www.hobbyking.com/hobbyking/...pacity_6S_10000mAh_Multi_Rotor_Lipo_Pack.html

I forgot to mention that my biggest requirement is to be able to continue to use the 1010P charger. I understand that i might have to two the two batteries separately.


----------

