Hi All, Merry Christmas!!! Happy New Year and Best Wishes on your Journeys...
I'm Ocean. After browsing and researching and reading several interesting threads, I'm excited to introduce myself here as I am now taking my first step into the world of EV's. I've wanted to do this for sooo long, and I finally jumped into something with style that I could afford to get started with.
I'm the proud new owner of the Bradley GT2 Electric Conversion that was recently listed on the EV Tradin' Post.
The Bradley is a sporty kit car from the 70's - early 80's. A fiberglass shell built over a VW Chassis. Overall the car is in very good condition.
The Bradley came with an 8" ADC Motor, and a pack of 15 essentially dead 8-volt LA batteries (120 volt system). The vehicle also has a relatively new Logisystems 750 Amp Controller (says 120/144volts on it), and a 15 amp on-board charger with variable amp / volt controls up to 170 volts. Nice Guages with amps to 500A and volts to 150V. Batteries were arranged in custom steel cages low in the vehicle - 9 in the back (around motor) and 6 up front. As far as I understand, re-building the pack is all that I need to do to get this baby back on the road. However, some TLC will also be involved.
So my big contemplation here is the new battery pack. My main concern is range, with a secondary desire for performance, and another primary concern for longevity of the pack. I want at least 100 miles... and 200 would be much better.
According to his page, Richard Slatin's electric Bradley GT2 at evalbum/916 weighs in at 1700 pounds with 10x 13volt NiMH batteries (130 volts nom) and has a range of about 65 miles...
So, trying to figure what my curb weight will be. I don't know what those NiMH batteries weigh, but I'm going to guess about 40 pounds per each (which would be just over half the weight of LA's in the size of a golf cart, which are usually around 70lbs each)... so that's 400 pounds of batteries in his car. Subtract that and I myself have a rolling chassis of about 1300 pounds.
So back to the battery: L-ion of some type, Of course. But how. I'm looking at 24 volt Tesla Modules. (6s @ max 4.2volts = 25.2 max voltage) I feel like 5 is not enough (25.2 x 5 = 126 max voltage of the system). 6 would give 151.2 max voltage. Now my concern: is that too much for the 8" ADC??? I don't know. Research suggest that it can handle it. It's listed as a 120 volt motor, but 120 nominal on LA's is at least 130 volts... (and it seems to be some people are out there running 8" ADC motors at 144 nominal) so... I'm thinking that about 150 max voltage would be ok. Thoughts on this???
So at 5.5 Kw per Tesla module, that would give a 33KwHour Pack (say 30 KwH conservative).... which sounds pretty good to start. The modules size (about 3" thick x 27" long x 12" high standing on edge) suggests it would fit nicely in the old battery racks (10.5 wide x 29 long x plenty vertical space in the back) - I could get 3 standing on edge together in one rack, on either side of the motor. At about 55lbs per module, I'm only adding 330 pounds to the curb weight for about 1600 - 1700 pounds.
Seems like this setup should get me at least 100 mile range. Any other estimates??? Could I expect more? What's that rule of thumb??? ev-propulsion.com/ev-calculations gave a nice formula of 250 - 300 Wh / Mile for a small car. I will say that this is a particularly small car with good aerodynamics.... so if it actually got 250 Wh / Mile that would give 30000Wh/250Wh/m = 120 miles which would be excellent. And in fact, in the long run, I can see adding another 6 in parallel (4 up front and 2 more in back) for a range of 200+ miles which would be ideal. Expensive though unless I find an amazing way to get into those batteries other than saving for a couple years...
The other possibility for me is to build my own custom pack for half the cost and 50x the work. I may be up to it. Anybody have any experience with FullRiver LifePo4 individual cells? Are they reliable to their spec is my main question. Looks like I can get large volumes of these off ebay for about 1/each (26650's) - and they are 3.3Ah x 3.2 volt nom = 10.56 call it 10Wh each. So, 3000 of those would yield a 30KwH pack... built in blocks of say 75p x 40 units in series I would then have 75*3.3 = almost 250 Ah pack at 128v nominal (148 max voltage, which I like because the volt meter goes to 150). Any ideas about how these configurations would translate to Performance on the ADC 8" motor? I would love feedback on these considerations. This pack would be a bit heavier I think than the Tesla pack, but it might have a longer life because of the difference in battery chemistry... any ideas on this???
About me: I'm an off-gridder in N. California. I've lived off grid with Solar Power
for the last 8 years and happily married for the most recent three+. Slowly building up our little piece of paradise out here on the land, growing food and living in a permaculture lifestyle. An EV is a natural step in alignment with our values that we're looking forward too. We use Solar Energy for almost everything. I plan to build an array to charge this car. If I can charge 100 miles of range in about 3 - 4 days that would be more than enough as I typically drive less than 50 miles per week but sometimes I need to go 100. I expect a 2kw dedicated array will do it. We get lots of sun. Ultimately I would like to have the EV drive down to visit family in the bay area which is about 200 miles. That's where the range really factors in...