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Discussion Starter #1 (Edited)
Hi everybody, Ella here.
have you seen these lightly used Tesla batteries from EV west?
they seem like a really good deal, and I'm feeling frustrated with the low range on my lead acid batteries. (I don't go farther than 6 miles round trip) my question is can I operate my motor with just 57 volts? it says on it 48v/72v.
I don't need more than 25 mile range so I thought just 3 of those 3kwh batteries would suffice.
my other question is: can I keep my old controller?
thank you for your patience!

thank you!
Ella from Virginia.

72 Karmann Ghia with 6 12v lead acid batteries
 

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Hi
I would suggest getting some Volt modules - they are cheaper than Tesla and seem to be very robust
They come in effectively 24v and 48v modules - complete volt batteries seem to go for around $1800 and have seven of the 48 volt modules and two of the 24 volt modules
The 48v units are 2 kWh and the 24v units are 1 kWh

Your motor will love about 150 volts - but your controller may be voltage limited

I would suggest getting a Volt battery and arranging it as two batteries in parallel to drop the voltage down to about 150 volts

If you use two of the 48v and one of the 24v in each string you will have 10 kWh - and three 48 volt modules left to use on an electric lawn mower or something

This is my setup three 48v and one 24v (twice) - but I have them in series - I run from 295v to 340v
 

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Where in Virginia are you?

For the controller, it won't go above 90VDC absolute max, without upgrading the controller to a different one.

I wouldn't use those batteries with your system at 57V nominal. I think you should try to get something that gives you closer to 72VDC. That would be possible with 3x Chevy Volt ~24V modules.
 

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The chevy Volt battery module (24V and 48V) are really good.
I you put your hand on a chevy Volt battery you will have access to two 24V modules and six 48V modules.
It will be easy to reconnect some modules to obtain a 67V nominal battery with 6 kWh of energy. This only imply to play with M6 nuts and busbar /wires.
The other 48V modules can be complex to split in 24V modules, so a good idea can be to reuse it for another application or sell it.
The dow side of this solution is that your range with 6 kWh of battery will probabaly be around 15-25 miles only.

Another interesting solution is to use 20 modules (7.4V each) coming from a first gen Nissan Leaf. This will shift your nominal voltage to 74V with 10 modules in series and two in parallel.

In any case you will need to learn about lithium cell. How to used it and how to charge it.
It's not complex, but it's dangerous to ignore it.
 

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Discussion Starter #6
Hi
I would suggest getting some Volt modules - they are cheaper than Tesla and seem to be very robust
They come in effectively 24v and 48v modules - complete volt batteries seem to go for around $1800 and have seven of the 48 volt modules and two of the 24 volt modules
The 48v units are 2 kWh and the 24v units are 1 kWh

Your motor will love about 150 volts - but your controller may be voltage limited

I would suggest getting a Volt battery and arranging it as two batteries in parallel to drop the voltage down to about 150 volts

If you use two of the 48v and one of the 24v in each string you will have 10 kWh - and three 48 volt modules left to use on an electric lawn mower or something

This is my setup three 48v and one 24v (twice) - but I have them in series - I run from 295v to 340v

Hi Duncan! thanks for the advice.
I never thought I'd want more power (I can do 50 mph on flat road), but if its really possible to give the motor more voltage without harming it I guess there's nothing wrong with not having to slow down traffic when going up hill.

I get how to wire the batteries, but I'm wondering if I would need to change the controller or if it can be reprogrammed. I'm also surprised by the price of a bms and a charger. are there cheaper options for slower low amprage) chargers?

also, if I was to use just two or three of those infamous Tesla batteries in series do I need a BMS?

thanks again!!
 

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Where in Virginia are you?

For the controller, it won't go above 90VDC absolute max, without upgrading the controller to a different one.

I wouldn't use those batteries with your system at 57V nominal. I think you should try to get something that gives you closer to 72VDC. That would be possible with 3x Chevy Volt ~24V modules.
Hi Travis! I'm in Louisa county, where are you? what vehicle do you drive?

what kind of controller would you recommend for this kind of motor (e-volks 19 hp)
 
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