[hybridreams]

Hello!

So I caught the EV conversion bug after watching Ben Nelson's DIY EV Geo Metro videos and pursuing some deep Googling on the possibilities of DIY hybrids (whereupon I found out about Dave Arthurs' hybrid conversions in the 70's and 90's!)

Now I am determined to see this project through!

I figured the easiest way to make a hybrid would be along the same lines as Dave Arthurs and created a series hybrid from an already converted EV. Found a local EV conversion being sold on Craigslist that was formerly a prototype for a local EV company, it just needs new batteries and the motor to be reinstalled. Definitely saves me the work of having to de-ICE the thing!

But, being a noob, I have a hundred questions. Currently, I'm wondering...can solar system batteries be used in an EV?? Like, in theory couldn't any kind of battery be used provided they provide sufficient V and Ah? I found four 12V 180ah batteries for 700 bucks. I figure that gives me 8.6 kWh, or roughly 55km range...depending how I drive
Definitely sufficient to get around town!

(Also, I realize these might be shit batteries, given their price...but I really don't mind.)

Thoughts? Would such batteries work???

These are the specs from a google search:

https://cdtechno.com/wp-content/uploads/2020/05/12_1037_MRF_0717.pdf

 

[Jordan325ic]

I love old-school EV conversions, but be aware that technology has improved a lot during the last 5 years, so keep that in mind when reading writeups written more than a few years ago. The proliferation of extremely high quality EV batteries on the used market has made other types of batteries pretty much obsolete.

Any battery can power an electric vehicle, but the big question is weight. The specs of that battery you listed show 115lbs per unit, so 460lbs for a tiny 8.5kwh. This is fine for stationary storage, but not for an EV. For comparison, I have a battery made out of newer Nissan Leaf modules that has 8kwh of capacity and only weighs 100lbs, total. This is without even getting into volume and discharge rate.

Also, 4 12V batteries only make 48V. Voltage is related to motor speed. 48V is extremely low voltage for an EV, to get any speed at all you'll need impractical gearing and/or extremely high amps. For a practical vehicle for public roads you will need 96V, at least.

In short, those batteries are not a good choice. I would do a bit more research before purchasing something you can't use.

 

[brian_]

Currently, I'm wondering...can solar system batteries be used in an EV?? Like, in theory couldn't any kind of battery be used provided they provide sufficient V and Ah? I found four 12V 180ah batteries for 700 bucks. I figure that gives me 8.6 kWh, or roughly 55km range...depending how I drive
Definitely sufficient to get around town!

(Also, I realize these might be shit batteries, given their price...but I really don't mind.)

Thoughts? Would such batteries work???

These are the specs from a google search:

https://cdtechno.com/wp-content/uploads/2020/05/12_1037_MRF_0717.pdf

One issue is power capacity. A solar energy storage system would normally be used to deliver the stored energy at a low rate, meaning low power - discharge over several hours. A vehicle needs bursts of relatively high power - high enough that if the power were sustained the battery would be discharged in much less than one hour.

The linked batteries are lead-acid, so they're heavy for the energy that they can store and their performance and lifetime are reduced by rapid discharge. The amp-hour capacity ratings (176 to 254 Ah) are based on discharge over 20 hours; they will be much lower at a realistic discharge rate. The highest power rating for the UPS12-615MRF model given in the table is 939 W, which can be sustained for 5 minutes, so with four of those batteries you could get 3.8 kW... which is more like a starter motor for a Dakota than anything that can actually drive the vehicle.

 

[hybridreams]

Hello! And thank you for your replies...

Yes, in the mean time since I made my introductory post, I have learned much about batteries (and EV's) and have since managed to acquire a full 48 Leaf modules that I will be using.