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Discussion Starter #1
So after much reading and watching videos I'm making a slow start on my conversion. Could be some time before anything happens with my car as I'm looking for another gearbox to firstly make an adaptor plate. I have a worn clutch plate to remove the splined centre from. Currently looking for a series wound dc motor. Would like to build a controller but cannot find anything in kit form. I watched all of Benjamin nelsons you tube videos but one thing that wasn't clear to me was, he said he had 6 X 12v batteries and was running 72v, so for a half wit like me that means it was 6 batteries in series, yet when he drove the car up a hill it showed 300amps. Is that possible, or is my thinking incorrect and that for example, 160ah battery has nothing to do with amps drawn instantly. If Benjamin's car had only 6 batteries and did up to 45mph but mostly driven at 30mph and had a range of 20 miles I could see maybe three times as many batteries in series and parallel would give me better range and a similar top speed. Looking at a more up to date set up and figures of £10k I really don't see the point unless it's more the build than the result, as a 3-4 year old leaf sells for £12k and it's a better appointed car than my 62 year old classic. Thoughts anyone?
 

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I watched all of Benjamin nelsons you tube videos but one thing that wasn't clear to me was, he said he had 6 X 12v batteries and was running 72v, so for a half wit like me that means it was 6 batteries in series...
Yes, six 12-volt batteries in series would run 72 volts.

... he said he had 6 X 12v batteries and was running 72v, so for a half wit like me that means it was 6 batteries in series, yet when he drove the car up a hill it showed 300amps. Is that possible, or is my thinking incorrect and that for example, 160ah battery has nothing to do with amps drawn instantly.
300 amps at 72 volts would be 21.6 kW, which is only 29 horsepower... so yes, that's reasonable power for a low-performance car. 300 amps is a lot for that size of battery, though.

160 Ah is 1600 amp-hours, which is a measure of capacity, not the rate that current can be provided (amps) or the maximum power (watts). At 300 amps, a 160 Ah battery would only last 160/300=0.53 hours (or 32 minutes)... and lead-acid batteries wouldn't last nearly that long at such a high current (they would only produce 160 Ah over a long period such as 20 hours).
 

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Discussion Starter #3
Yes, six 12-volt batteries in series would run 72 volts.


300 amps at 72 volts would be 21.6 kW, which is only 29 horsepower... so yes, that's reasonable power for a low-performance car. 300 amps is a lot for that size of battery, though.

160 Ah is 1600 amp-hours, which is a measure of capacity, not the rate that current can be provided (amps) or the maximum power (watts). At 300 amps, a 160 Ah battery would only last 160/300=0.53 hours (or 32 minutes)... and lead-acid batteries wouldn't last nearly that long at such a high current (they would only produce 160 Ah over a long period such as 20 hours).
Thanks for replying. The ice in my car is 35hp which I believe is about 26kw, so how many lead acid batteries would I need to achieve that. With developments in new battery technology coming I'm reluctant to spend huge amounts of money on lithium batteries and how to maintain them is something I know nothing about.
 

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The ice in my car is 35hp which I believe is about 26kw, so how many lead acid batteries would I need to achieve that.
I don't know - lead-acid isn't used for any vehicle beyond a golf cart now. ;)

With developments in new battery technology coming I'm reluctant to spend huge amounts of money on lithium batteries and how to maintain them is something I know nothing about.
I wouldn't wait for newer battery technology - you could spend the rest of your life waiting, because there's always some miraculous new thing being promised.
 

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I don't know - lead-acid isn't used for any vehicle beyond a golf cart now. ;)


I wouldn't wait for newer battery technology - you could spend the rest of your life waiting, because there's always some miraculous new thing being promised.
As I said in my first post, the cost ramps up with lithium batteries and may as well buy a 2015-16 leaf if it's a daily runner you are wanting. I'm not wanting that, my car is historic and driven locally to car meets and the odd run to the shops. I have driven it 60-70 miles but it's not pleasant and noisy but with electric conversion I expect it to be less of a chore. I saw a video of someone spot welding 40ah pouches together but don't know where I could buy them. I also heard there can be problems charging and looking after lithium batteries. Problem is some people that have successfully converted cars are now charging for their time along with the people that are making their living from it. I understand they must be bombarded with questions from people like me so that's fair but it wouldn't be my way. I always help people whenever I can.
 

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Hi Paul

You need used batteries from a crashed EV - I got a Chevy Volt pack for $1800US - 16 kWh
It's made of 9 smaller modules that can be put together different ways depending on what you want

Here is a useful thread
https://www.diyelectriccar.com/forums/showthread.php/2012-chevy-volt-battery-93101.html

I know it's long but it's worth a read

This is my car

https://www.diyelectriccar.com/foru...dubious-device-44370p15.html?highlight=duncan

I didn't bother with gearbox - I can spin the tyres in "top gear" so it didn't seem to be worthwhile

Go for it!
What type of car is it?

The biggest problem with an old car is finding somewhere to put the batteries - especially for me as I wanted everything that was heavy to be on the floor so I have a very low C of G
Ask away and we will try and help you
 

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Discussion Starter #7 (Edited)
1957 ford popular, I would post photos if I could but it looks like they need hosting somewhere and I've given up on finding a site that makes sense since photobucket lost the plot
I think siting batteries will be ok, remove the fuel tank and replace with a box under the boot/trunk.
Under the bonnet/hood and under where the rear seat is. Either keeping the seat or not as never had anyone in the back.
 

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Not likely to find a Chevy anything here in uk but Nissan Leaf is more likely. My mate said he knows people who would steal one to order but let's not go there that is totally out of order, I do hope he was joking. Gearbox has to stay for my car to retain its historic status.
 

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I'm in NZ
I got my Volt pack shipped here total cost was $3,300NZ - about 1600 pounds

To put pictures in click on "Go Advanced" and then "Manage Attachments"

Then download the pictures from wherever you have stored them

Sure you can't lose the gearbox? - it just gets in the way
 

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I saw a video of someone spot welding 40ah pouches together but don't know where I could buy them.
Do-it-yourselfers do not buy pouch cells and assemble them themselves; even most auto manufacturers don't do that. There are two practical approaches:
  1. use prismatic cells, with threaded terminals for connecting straps or cables, or
  2. use modules of multiple cells already connected in some suitable parallel then series configuration, typically salvaged from an EV.

I also heard there can be problems charging and looking after lithium batteries.
Yes. Lead-acid, too. Overcharged lithium cells can dramatically burn up, so it is important to limit the charging voltage; some people just pick a conservative voltage per cell and limit the pack based on that, not using a BMS to control charging. Undercharged lithium cells can be damaged; some use the same approach for a protective shutdown based on pack voltage. Imbalance between cells is either a huge problem or a non-issue, depending on who you ask. All of this except the fires applies to lead-acid, to some extent, and all of it will likely apply (or be even worse) with whatever the next great technology might be.
 

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Discussion Starter #14
Only recently heard of the Vauxhall ampera, no idea how many have been sold. All seem rare as rocking horse poo. Seen some Lexus hybrid batteries for sale but quite old.
 

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Literally any used Lithium pack will be cheaper than equivalent energy you can actually get out of lead-acid.

And, consider that lead-acid will last about 2 years, with declining performance, and then need to be replaced.

There's a guy in the classifieds section here, selling Volt packs (nearly one full one), for $900/half. So, $1800 US total.
 

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Discussion Starter #17
Literally any used Lithium pack will be cheaper than equivalent energy you can actually get out of lead-acid.

And, consider that lead-acid will last about 2 years, with declining performance, and then need to be replaced.

There's a guy in the classifieds section here, selling Volt packs (nearly one full one), for $900/half. So, $1800 US total.
I'm not looking for equivalent energy as in say 24kwh which everyone seems to think is what's needed. At the risk of sounding like a broken record, I'm not looking for 100+ mile range or 70mph. I'm thinking simple dc motor say 72v supply 20-30 mile range 50mph maximum. The car with 1172cc sidevalve 35hp has maximum speed 60mph, acceleration measured with a calendar not a stop watch. Ok lead acid is history you say and yes I would agree if your expectations have to meet current ice powered cars. One thing I've noticed when looking at manufacturers electric cars is after four years none I've seen for sale have more than 32000 miles on them, which shows how little use they can be put to. Good if you can find a crashed one and get the battery pack.
So next I expect as before the tesla argument on range but let's be honest here, they have like 85kwh battery pack and are hugely expensive. So rant over and please indulge me. Put together a set up with lead acid and series wound dc motor for my 750kg car with low expectations on speed and range. This is my first foray into ev and is not a daily but my hobby car going to car meets etc.
 

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I'm not looking for equivalent energy as in say 24kwh which everyone seems to think is what's needed
I think you think this is more complicated than it is.

To restate things... there is no point in using lead-acid batteries, ever. Lithium is better in every way, including price. Including even if the lead-acid batteries are free.

You want a small pack? No problem. Lithium still works.

72v worth of Lead-Acid is going to be 6 deep-cycle batteries which will cost at minimum $125/each. $750. And you'll get around 7kwh at a 20h rate, or more like 3.5kwh at a 30 minute rate. So, that's about what you need to go 50mph and 30 miles. And you'll murder your batteries doing that.

Random overpriced link you could buy today: https://www.ebay.ca/itm/2014-Chevy-...ash=item3413d11c8c:g:NWoAAOSwkGpdgnEu&vxp=mtr <-- 72v, 3kwh, $620.

And they'll just about last forever, you won't need to replace it in 2 years.
 

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Looks like the ampera has been around since 2014 and until now I had not heard of them. Great marketing by Vauxhall.
The Volt was never really advertised here, either... only promoted in press releases and media events. GM never really wanted to sell a lot of these cars, because they are not profitable - they just want to develop expertise and appease both government regulators and environmental advocates.
 

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I'm not looking for equivalent energy as in say 24kwh which everyone seems to think is what's needed. At the risk of sounding like a broken record, I'm not looking for 100+ mile range or 70mph. I'm thinking simple dc motor say 72v supply 20-30 mile range 50mph maximum.
I think we all understand that. No one said "use a complete EV pack", but I said...
  1. ...
  2. use modules of multiple cells already connected in some suitable parallel then series configuration, typically salvaged from an EV.
Not all of the modules, just enough to meet your needs. That might only be half or a quarter of the full set that come in the EV.

Also, 24 kWh is typical for a low-end EV (or was until a year or two ago), but the Volt/Ampera is a plug-in hybrid, not a battery-only EV... it has a much lower capacity battery than a typical EV. The larger second-generation Volt still only has 18 kWh nominal (and less usable).

Even Duncan's car, which is used for drag racing and runs much higher voltage than typical for a brushed DC motor, doesn't use quite all of a Volt pack (it's one module short to package properly in the car).
 
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