Add an additional 8Kw battery to double the range

should have got a lift back. 5 seats, spare tyre and a full hatch.

 

Increasing the pack in the Prime by another 8.8kWh will likely cost as much as opting for those extras on a Volt, and cover some of the models' price difference.

Convert it to a 50 mile plug in, and show Toyota how to package the battery pack.

 

Speculation is fine but we have today's facts and data:

• 100 miles each way, daily commute - TSS-P is standard on the Prime
• $0.21/kWh average New York electrical rate - reduces the advantage of a larger battery over gas efficiency
• some ambiguity about a free charge at work, @Banstro

I'm hoping @Banstro gets a chance later to provide more facts and data (i.e., $/gal regular, $/gal Plus, $/kWh.) If he hasn't reset the ODO MPG, we could calculate a 'back of envelope' ratio of electric to gas miles. But we'd really need his local electrical rate and gas prices to make a better economic model to apply against the big three:

1. Prius Prime
2. Volt
3. BMW i3-REx

Bob Wilson

 

Yup. When the home brew Gen 2 plug-in mods were (somewhat) popular, there were no other options but to roll your own. Today, we have choices.

 

Bigger battery pack would be nice, but as others were saying, we'll keep wanting more. Not to mention, battery technology has a LONG ways to go before it can provide 1000 miles on a single charge, without taking up space, and allow for quick recharging, and be cheap. Most of us need to keep waiting.

 

Yes, the BMW turned out to be ‘delicate’. Having the Prime as backup works for me.

Bob Wilson

 

True, but a really good mod would lower the normal battery 4" so it is at the bottom of the trunk. That way the new battery would not encroach quite as much into our luggage space (currently insufficient for an upright grocery bag beneath the tonneau cover! Now there is just tons of unobstructed empty space under there! Actually I'd like to see a mod that just shortened the pedestals the battery currently rests on. I have posted under-pictures elsewhere in this forum. Before you say cooling, the are two powerful blowers (one on each side fed for vents next to the rear seats) forcing air through the battery and (it appears from the plumbing) out the bottom of the car.

 

Not worried about cooling, but the fact that the well under the battery was designed for a spare tire, so is rounded and smaller than the current pack. Any modification to get it to fit in three will involve cutting out the sheet metal ledge the battery rests on, which will effect structural strength of the frame, or building a new case, and repackaging the battery.

Cooling becomes an issue if you plan to simply 'slip' the additional battery into that empty space. Got to make sure enough air flow can be brought to it. The blowers are going to be running more often with any of the additional battery near the original. You've added more heat producing mass to a confined space.

What about cost? I figure you will likely have to buy a totaled Prime to get the extra pack at this point in time. It will also provide parts for testing modifications to the car.

If you are serious about this, I suggest reaching out to the people that did the plug in kits for the gen2 and gen3 for advice.

 

just put the back seats down and put a wrecked tesla battery in there.

 

I suspect the specific battery chemistries don't much up, meaning different voltages and amperages between the cells.
Putting in a liquid cooling system would be the bigger hurdle though.

Thinking about it, I believe some of the plug in kits did use lead acid batteries.

 

new, or salvage?

 

$5,000. and $1,000.

 

If it turns a once a week visit to the gas station into a once a month visit, regardless of $ savings, would that be worth it? It would to me.

 

The Prime hasn't been out long enough, or sold in the numbers, for the battery pack price to be public knowledge at this point.
However, a replacement for the earlier generation Prii run around $1500 to $2000. Those are about 1.5kWh capacity.
My guess is at least $5000 for a Prime pack.

 

new leaf is looking good.