Building a battery pack (cheaply)

[oil pan 4]

Originally Posted by AlexanderB

Ah, yeah.

I wonder though, is spending all that money really worth it? because I think $350 worth of cells and whatever worth of extra materials just to replace a $100 starter battery is kinda.. pricy.

It was for a diesel and it takes 2 batteries. If I only bought the cheap $100 batteries I would be replacing them after about 2 years.
My lithium batteries are 2 years old and still appear to be just as strong as the day I started using them.
The switch to lithium also saved me 100lb of weight.

[planetaire]

Originally Posted by Xist

How is the plug-in-Prius different?

This one use lithium cells, about 4.5 kWh. The Prius + (7 seats) in Europe have lithium cells, between the 2 front seats. But for this one it is more to have place for the 6 and 7 seat.

Originally Posted by Cobb

Id give you an award since you figured it out. I dont know of a single American who has successfully used the PP BMS. On the Insight forum there was a group buy to make a lifepo4 insight if not a PHEV mode, but only 1 guy has come close to making it work, not counting Peter.

Thank's for the award.
But we are several using his bms in our Prius. 4 guys today in France.
You have to be carrefull because there is a ttl bus that have to be shortened as much as possible and because in a Prius you have huge and quick voltage variations between the cells and the car body. Then we use a bluetooth to communicate whis a PC and the bms send twice each voltage value in order to know if one have been modified by a "spike".

His bms is low cost, modular, safe. During charging if any problem occur it is easy to stop this process. So cells won't be damaged.
I would have believed that it was easier in insight because there is less cells. We have 70 lithium cells in our Prius so ttl bus could be longer.

[Xist]

Originally Posted by planetaire

This one use lithium cells, about 4.5 kWh. The Prius + (7 seats) in Europe have lithium cells, between the 2 front seats. But for this one it is more to have place for the 6 and 7 seat.

The Prius + is called V in North America and apparently Alpha in Japan. This is the first that I heard of a version with a third row in the trunk:


Supposedly they did not think that it would sell well here where many people purchase vehicles with third rows. I saw several comments that Toyota would be required to install additional airbags, which would drive up the price further.

[AlexanderB]

Not much (or, y'know, any at all) space to put your legs in the third seat row in the Prius +. Same for most other small minivans/wagons like that.
Its nice as emergency seating if you have to bring an extra person, but its really uncomfortable.. (Back when I was a kid, I'd just sit in the back of a stationwagon with a bunch of kids when going to a birthday party, I guess this is a slightly safer, more legal alternative to that.)

Originally Posted by oil pan 4

It was for a diesel and it takes 2 batteries. If I only bought the cheap $100 batteries I would be replacing them after about 2 years.
My lithium batteries are 2 years old and still appear to be just as strong as the day I started using them.

Ah, I see
My lead battery lasts longer (for now). We'll see.

Originally Posted by oil pan 4

The switch to lithium also saved me 100lb of weight.

Thats quite a bit, but how much is is compared to the weight of the truck?

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A different question, I found another 97 laptop batteries, but the seller won't ship. Do we have any members in/near London who can pick them up and ship them?

[Cobb]

Yeah, Ive thought about the prius v for a larger car as the insight is just too small and so is the civic.

Wow, 4 guys not counting Peter himself? Amazing how the guys over seas are smarter than everyone else. You could make some money selling them to the US market. I think the American I know of working with it had to over come PAL vs NTSC for the display, then there was another issue that held everything up.

Originally Posted by planetaire

Thank's for the award. But we are several using his bms in our Prius. 4 guys today in France.

[AlexanderB]

I just got an offer to buy approx 3000 18650 cells. Lets hear how much the guy wants for them. Also, thats like 150 kg of cells, I'm gonna have to pick that up by car, in Germany!

But first see what he wants for them, because I am not made of money. (In fact, I just noticed that by next year, I'll probably be in slight financial trouble, because my study grant runs out, while I'm still expected to do 2 more years of fulltime study. Whoops.)

Anyway, and I got some other batteries on their way, I'm looking forward to when all this stuff starts arriving in the mail, and I get to start sorting out the cells and stuff.

[Cobb]

Using grant money for college for an EV project? Thats very American of you. Some just blow it on non renewable stuff to get women or just supplement an income cash flow problem.

[AlexanderB]

Well, when the EV is finished, it would save me money in car costs, so I consider it an investment, I guess. I'll pay less to go to work/study/family in the future, and be green at the same time.

I really don't wanna discuss my choices in life in this topic, but lets just say others probably conclude I wasted years of my life (and college funding) doing other things, like fixing up my car, helping building a solar powered racing boat, etc.. On the other hand, I think I have some valuable life experience, had lots of fun, and I know what I want and where I want to go now, where I was previously very aimless and unsure of what I wanted carreer-wise and otherwise. Too bad I got kicked out of Mechanical Engineering for not completing 1 math class, or I'd be in my final year already. Oh well.

[oil pan 4]

Whats shipping between countries in Europe?
I never stayed there long enough to find out.
Shipping to the US and Canada is prohibitively expensive for nearly everything it seams like.

[AlexanderB]

Yeah, shipping *from* the us (unless it fits in an envelope) isn't fun either.

Shipping between European countries varies, as each country has their own national mail, and a few companies like DHL and stuff like that. Some are really expensive, some not so much. 150 kilo from Germany would probably cost me in the order of 200 euro in mail cost, *if* it could be shipped by mail. Its probably cheaper to go and get it.

The trouble with my current project is, no mail company will touch a (large) shipment of lithium batteries with a 10 foot pole, too scared it'll spontaneously combust in their airplane/truck. So either I have to go pick it up myself, or I have to hire a freelance courier with less strict rules. (Like I did to get my batteries from the UK.)
Or I ignore the rules, don't mark the box, and hope the mail company doesn't get nosy as to whats inside..

Talking about courier, I wonder when he'll be arriving here. I haven't heard from him since we arranged the details of the pickup. I guess I'll email him tomorrow and see.