light batteries with low AH, or heavy batteries with high AH

[4dollarjoe]

Hey so I am in the process of planning the build for my own electric motorcycle. I was looking at some walmart batteries, which are marine deep cycle batteries. They have an excellent AH of around 120 ah for only $100 with a free 5 year warranty. The issue is that they weigh 60lbs a piece, so that means my 48v system will weight 240lbs. On the other hand I can get lithium ion batteries, which for $200 have a 24-32ah rating; and they only weigh 3 lbs.

I want my build to have fast acceleration and feel powerful, but I also want long range. The beach is approximately 24 miles round trip, so I want something with a good 10 mile buffer to ensure that I won't get stranded and have a bad day.

How can I calculate my range, I've heard that you can assume that 100watts will get you a mile, but how does weight and stuff play into it? For example the 120ah heavy batteries will give me 5760 watts or 57.6 miles per charge; but will that be true? The lighter batteries be 200+lbs lighter but only will give me 1536 watts, or a pathetic 15.36 miles.


What should I do? What is the better option?
http://www.walmart.com/ip/Deltran-Battery-Tender-26-35A-Lithium-Battery/32833009

http://www.walmart.com/ip/EverStart-Maxx-Group-Size-29-Marine-Battery/20531539

 

[Laserman]

Most la batteries ie marine do not have support for vibration ie waves does not give as much as road vibration will,

 

[liveforphysics]

Lead Acid only gives you a small portion of it's rated capacity, and it's in the process of failing from the moment it's made.

 

[battman]

For the lead acid, 120AH at 60lbs would be 53Wh/Kg which is not a credible energy density for this type of battery even under "ideal" conditions (e.g. discharging at one milliamp at 25 Celsius).

 

[John in CR]

Forget lead acid batteries for an emoto. I made that mistake on my first electric build back in 2007. The only result can be a heavy pig moto with terrible performance and short range...or maybe an obese pig moto with worse than terrible performance and moderately short range.