[A.godfrey]

Hi,
I am thinking a little ahead to when I get the batteries and controller. Currently I intend on getting a 72V controller due to the fact that they are cheap and easy to get (probably a Curtis one) according to my ebay searches.

I also intend to get 12 fairly cheap and cheerful 110 Ah flooded lead acid batteries and pair up 2 batteries in parallel and put these pairs in series.

this way the Ah rating for the 'bigger batteries' that I have made will be bigger but the operating voltage would be the same, so I could use a cheap controller but have a decent range.

My questions are, will this increase my capacity/ range and is it safe to do this? any thoughts on this idea would be appreciated.

Ta,

Al

 

[Duncan]

How far do you want to go?
If it's more than about 15 miles forget the lead

 

[dougingraham]

You want to run the voltage as high as the motor will allow. This gives you a wider torque band. Running low voltage you will have to shift sooner and may limit your top speed to something less than what you want.

It is ok to parallel lithiums and lead acid batteries. But like Duncan says if you want more than 15 miles of range forget lead. The weight kills you. You quickly reach the point of diminishing returns. In theory doubling the battery would give you double the range but the additional weight cuts your range and gives you a vehicle nobody would ever want to drive.

Lead Acid will cost you more long term. At about the 5 to 6 year mark Lithium pulls ahead cost wise but smile wise it occurs in the first 10 seconds.

 

[A.godfrey]

ok fair point. thanks I still intend on going for a smaller voltage system due to the cost of the controllers and availability. Do you know a good cheap (ish) site or place to get LiFe PO4 's from? as I might look down that avenue.

My aim is to get as large range as I can with a 72V system.

Thanks.

 

[A.godfrey]

can you use smaller Ah ratings for the LiFe PO4 batteries because you can safely discharge them more?

What sort of Ah rating is good?

 

[Yabert]

can you use smaller Ah ratings for the LiFe PO4 batteries because you can safely discharge them more

Kind of yes...

My aim is to get as large range as I can with a 72V system

You can do the same range with a 72v, a 144v or a 360v systems. There is others variable than voltage. A 72v systems can be good and cheap, but only for lightweight vehicule at speed under 60 mph.

My advices:
-Continue to learn and ask question before buying any components
-Take a look at Leaf and Volt battery available at scrapyard and different places.
-Consider Alltrax controller instead of Curtis.

Good luck.

 

[A.godfrey]

Kind of yes...

You can do the same range with a 72v, a 144v or a 360v systems. There is others variable than voltage. A 72v systems can be good and cheap, but only for lightweight vehicule at speed under 60 mph.

My advices:
-Continue to learn and ask question before buying any components
-Take a look at Leaf and Volt battery available at scrapyard and different places.
-Consider Alltrax controller instead of Curtis.

Good luck.

Oh ok Thanks for the advice. i'll look for some leaf and volt batteries, if I can find any that is. Iv also looked at a DIY controller - paul and sabrinas kit, sounds good almost like those amplifier kits you make as kids but on a larger scale.

well as they say ... back to the drawing board!