# COnverting a 1961 Cadillac



## madderscience (Jun 28, 2008)

Hello and welcome to the forum.

Dare I ask what kind of gas mileage that cadillac gets / used to get? 10mpg if you are lucky?

At least with lead acid conversions, the range you typically get is usually somewhere around the distance you could get on between 1 and 2 gallons of gas in the vehicle before conversion. For example, my toyota MR2 originally got about 30 miles per gallon, and as an EV its maximum range is about 60 miles at 55mph under good conditions, and a safe 30 miles under really bad conditions.

to get 120 miles of electric range at 65mph in a vehicle like your caddy, you are in big budget lithium battery territory. You would be looking at an 11" or 13" DC motor and a 1000A controller, or a comparably large AC motor and inverter to get sufficient horsepower. 

To use a really rough comparison, assuming the cadillac got 10mpg, then a battery like the one in my car (1250lbs of lead) would give maybe 20 miles of range, maximum, under good conditions. This means you need 6 times my battery, which would be completely infeasable usiing lead acid (7500lbs). However lithium gives you about 4x the energy density, or 1/4 the battery weight, for the same amount of stored energy. This means about one ton of lithium (minimun, with no margin for error) would give you range somewhere around what you are looking for. I am sure that caddy would not even be breathing hard with 1 ton of lithium on board. 

As another data point, the Tesla roadster has about 1 ton of lithium on board, and with its otherwise sleek, lightweight body based on a lotus elise, it can cruise about 240 miles. So if you can achieve 1/2 of the efficiency of the tesla you can get 120 miles with an otherwise identical battery pack and equally efficient drivetrain, then you could go about 120 miles. I suspect getting even 1/2 the efficiency of a tesla out of a converted 1961 cadillac will be a challenge.

Look at the various range calculators and do your math (brushing up on high school physics as necessary) and ensure that it will be feasible (economically and technically) to do what you want.

This is not going to be cheap, but for all I know you are neil young's cousin and can afford it 

http://www.hybridcars.com/news2/neil-young-linc-volt-hybrid.html

Good luck.


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## big-boss (Jul 28, 2009)

Thanks, that give me a great start. Has any body put an electric motor behind the transmission and made sort of a Hybrid like my GMC Yukon.


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## TheAtomicAss (Feb 19, 2009)

madderscience said:


> As another data point, the Tesla roadster has about 1 ton of lithium on board, and with its otherwise sleek, lightweight body based on a lotus elise, it can cruise about 240 miles.


The Tesla has a full 2,000lbs of batteries?

Is that raw cells, or does it include the infrastructure?

Based on my calculations, if using TS or SE prismatic cells, I can cram ~50KWh into ~1,100lbs, WITHOUT infrastructure. I don't expect infrastructure to exceed 200lbs.


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## madderscience (Jun 28, 2008)

my bad; the tesla's battery weighs about 1000lbs, not 2000lbs as I thought for some reason. The whole car weighs about 2700lbs, acording to wikipedia.

the tesla uses lithium cobalt cells I believe (but this is the same memory that got the weight wrong) whereas TS cells are a safer but less energy-dense LiFePO4 chemistry so you will need a bit more weight to compensate for the reduced energy density. And yes, this weight does not include all the care and feeding stuff, support, cabling, etc.


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