Feasability of going from gas to only electric

[dremd]

Point of diminishing returns is further out than you would expect for 2 reasons
1) pukert makes the effective capacity higher with more cells due to lower discharge rate.
2) battery pack remains useful longer as capacity decreases.

Sure weight adds up, and eventually takes over, but largely more battery gives more power range and efficancy.

[dremd]

Originally Posted by freebeard

Get the world's smallest boat trailer and you are good to go.

Did I miss something?

I'd love to drag the electric boat around with the electric car, but I don't want to dip the hatch of the leaf in the water (we could build an extendable toung) and I'm not sure it would drag that much mass up a ramp steep enough to get the boat on and off the trailer.

[Isaac Zackary]

Originally Posted by WyrTwister

Have you heard of the law of diminishing returns ?

More batteries , more weight . More weight , more electricity / energy is required to move it . More energy / electricity required , more batteries needed .

God bless
Wyr

Yes and no.

Doubling the battery capacity (i.e. 48kWh instead of 24kWh) won't double the range, especially if I'm putting these on a trailer. But it will get me farther down the road regardless.

Another 24kWh is another 600lbs of batteries. That's not the same as adding another ton and a half car. Plus it's not so much about weight as it is aerodynamics. Some have added another Leaf battery in the trunk. That does reduce how many people can ride in the car and how much luggage you can take along, but doesn't affect aerodynamics. Putting the batteries on a trailer will affect the aerodynamics, but the trailer will be drafting the car. It will add more rolling resistance too, but it's still less than half a car's worth. So in the end, the car will still be able to go farther despite the added weight, aerodynamic drag and rolling resistance.

Right now I could drive from charging station, RV Park or friend's home to charging station, RV park or friend's home, but would have to take it very easy since according to the NissanConnect EV Route Planner I'd only make it with one bar left between some charging stops. A battery trailer would solve that. Although a more aerodynamic tail would also help. Maybe I could do both.

[Isaac Zackary]

Originally Posted by dremd

Did I miss something?

I'd love to drag the electric boat around with the electric car, but I don't want to dip the hatch of the leaf in the water (we could build an extendable toung) and I'm not sure it would drag that much mass up a ramp steep enough to get the boat on and off the trailer.

I was wondering the same thing.

'freebeard'. Maybe you meant "boat tailed trailer" for hauling around the batteries?

[freebeard]

It's 'freebeard'. I feel so misunderstood.

I had to go back and look; apparently I was suggesting that that roll-around power pack wouldn't need an Harbor Freight trailer with a deck as that would be redundant. Sorry for not being more verbose. Perhaps I was pressed for time.

I came here to suggest http://ecomodder.com/forum/showthrea...tml#post528238 here bottsapper posted a video of Jehu Garcia's range extender trailer for his 23-window bus.

[Isaac Zackary]

I really like the idea of the battery trailer. With that I'm wondering what would be the best way to connect it electrically to the car. A simple parallel connection? Parallel everything (each cell so all can be balanced together)? Or switch between battery packs? One other way would be to hook the spare pack up as a pusher trailer with it's own motor.

It seems that any which way will work. But there are benefits to hooking up each pack separately. That way the car can balance and monitor each battery. According to the video I posted earlier they were able to set it up so that when switching between batteries the car could tell which battery now had only 9 bars left and which battery had 12 bars. If I hook up in parallel I wonder if that function would be lost (making the car think the battery is in excellent condition even if both batteries should be several bars down.)

Another idea is to just throw a generator in the trunk and use it in case of emergencies. This may be the cheapest option. I found a 2,500W propane inverter generator on eBay refurbished for $700. Now I'd only be able to level one charge, but the guys that can upgrade the EVSE can also make it accept 15amps instead of 12. I like the idea of a propane generator because the propane shouldn't ever go bad nor cause bad smells on the car. I could do that and then just focus on aeromods and perhaps dual level 2 charges.

[oil pan 4]

My generator could run double level 2 charges but won't fit in the trunk.

Why do you want a battery trailer?
You do know that every day you don't use it the battery trailer the battery it's life is still withering away?
The best industrial lead acid stand by batteries kept at a steady 70°F and rarely used still get replaced about every 5 or 6 years.
Rarely used stand by generators can last 30 or 40 years and all they need changed is the oil, fuel and battery if it has one.

[Isaac Zackary]

Originally Posted by oil pan 4

My generator could run double level 2 charges but won't fit in the trunk.

Why do you want a battery trailer?
You do know that every day you don't use it the battery trailer the battery it's life is still withering away?
The best industrial lead acid stand by batteries kept at a steady 70°F and rarely used still get replaced about every 5 or 6 years.
Rarely used stand by generators can last 30 or 40 years and all they need changed is the oil, fuel and battery if it has one.

I suppose it's mostly about cost. If I could get a whole wrecked Nissan Leaf for less than $1,000 and throw the batteries on a trailer and scrap the rest of the wrecked Leaf I could make my own Leaf have a much larger range for cheap (cheap as far as electrics go.) At the same time it would still be all-electric.

[freebeard]

Pursuant to the 'boat tail trailer':



I did this for another discussion. If you separate the load into two lumps you could have a seat in the middle of the boat. I don't recall if the discussion touched on whether you'd want the boat backwards. Like this:



For the battery packs what you want is 'hot swappable', a controller that will tolerate intermittent sources, maybe with a configuration switch or [soft] buttons. Does Litthium-ion have better standby life?

[oil pan 4]

Lithium ion appears to be all around better than lead acid aside from price, cold preformance, cold charging and ease of replacement.
Also lithium batteries do not appear to be recycled in the US.

In my diesel suburban I was going through 1 or 2 starting batteries per year, didn't seem to matter if I was daily driving or weekend only driving it. It's had the same lithium battery since late 2012.

As far as wrecked Nissan leafs go I have only ever seen them go for 2000 to 3000 on ebay. There may be 1000 ones out there but they would have to be totally trashed.