Battery Vehicle Society

Hi Guys

There is loads of info out thee, but I can't really make much sence of it all... I would like to price up for the following in LiIon or LiFePo cells for my cinquecento:-

System Voltage: 96v
Capacity: 100Ah - 150Ah
Max current draw: 300 Amps, approx

BMS and charger included...

Maybe someone could point me in the right direction?

geekygrilli wrote:
System Voltage: 96v
Capacity: 100Ah - 150Ah
Max current draw: 300 Amps, approx

BMS and charger included...

Maybe someone could point me in the right direction?

My calculations here: http://groups.google.com/group/audia2ev/web/batteries. 500euro/kWh tax and delivery included on my order, your mileage may vary of course. Working on your numbers with my parameters, £4500 to £7000 for a pack from 10kWh to 15kWh. My units were 50Ah, I don't know if bigger units are more or less expensive.

Cheers Simon

My current lead acid leisure batteries are on their way out. They've only done 2000 miles, but to be fair I have abused them a lot; thy've been shorted, run flat more than once, stored almost flat for a year, sat on a floor at -10C, etc...

I can replace the lot with exactly the same batteries for £400, which means I can just dop them straight into my car with hardly any effort. I also know how to look after them better now!

I expect (hope and pray) that Lithium technology will get get much cheaper and by the time my next set are knackered I'll be able to afford some LiFePo.

Hi Guys,

I don't see any calculations or allowances for BMS, enclosures and vehicle integration?

Have you got a solution for the HP cells?

Cheers,

Ian

ChopperMan wrote:I don't see any calculations or allowances for BMS, enclosures and vehicle integration?

I take your point Ian, I guess it is the difference between the cost of the system on the left side of my spreadsheet and the ball-park TS and HP numbers for a similar sized system... so... that would be... best get the calculator out....

More seriously:
- vehicle integration: well, each of such projects is pretty much a unique event and in my naivety I'm not sure what that means really. My controller needs a red and a black wire connected to it. In fact, an advantage of a system that does break up into lots of cells is that integrating them round the car is, I think, going to be more flexible (not necessarily easier though)
- enclosures: indeed it would be nice to have my cells come very modular and not too DIY. The Zebra would have been great - one box, two wires? A what cost though... With relatively modest requirements to put the cells in my car, I don't see I'll have much more work than if what I had bought came already "bundled". I might have to learn to weld, though...
- BMS: indeed a serious subject. The HP charger at least should manage the balancing correctly, albeit it is not a complete BMS. I've seen a few TS systems that appear to have a BMS though. Overall the costs I've had quoted are compatible with what I've said above, however.

I would add another caveat: performance. The performance of these systems is clearly not equal. But that's difficult to quantify and obviously depends a lot on what is required for the vehicle.

To anyone in general who is a bit shocked I placed the numbers on my site: when I was looking for information on this very important investment, information on what was available and where to go was really hard to find. (several distributors were very helpful, several not). Prices of course will vary and so what I found, last summer, isn't a perfect guide to what you can expect today, or even then. But at least there's a range of choices that I think might help someone think, contact dealers, ask questions, and then decide what they want to do: stick to lead acids, by a modular box, or try DIY LiFePo...

Chris
Here's a link to a European distributor of lithium ion that may give some idea of prices at the cheaper end of the market – although again no BMS, which seems to be essential.

Simon
Sounds like a nice project – a lot more challenging than my mini conversion, but I have very limited electronic skills so I have to keep things simple. You've probably already thought about this, but I notice you mentioned breaking up the battery pack. From what I've read of others' experiences with lithium packs, they stress the importance of keeping the pack together, or at least making sure that temperatures and wiring runs are kept as uniform as possible to avoid imbalance between cells. Just a thought.

MalcolmB wrote: You've probably already thought about this, but I notice you mentioned breaking up the battery pack. From what I've read of others' experiences with lithium packs, they stress the importance of keeping the pack together, or at least making sure that temperatures and wiring runs are kept as uniform as possible to avoid imbalance between cells. Just a thought.

Indeed had short thread on this forum about this. HiPower expressed no problems on the issue. I think I'll be monitoring temperatures very closely given recent events with Greg's 126... On cable length, the whole pack being in series should mean less sensitivity on this, I think. Thanks for the tip.

Ive seen figures of the Z5 Zebra battery of 15.5k Euros today. Apparently if they got the production figures up to where they expected they would be £4k each!

286V, 76 Ah 21.2 KWh rating and 224A peak discharge.

Seems there a bit of a difference between 2hr discharge and 20 though, 2 hr is closer to 17KWh.

182 in the box with the BMI.

Hello Jonny. Welcome!

Tell us more about these Zebra battteries. I know Modec were using them, and Zytec/Smart and Steve Green with his Citroen C3, but I haven't heard prices or effective capacity before.

What does your final statement, "182 in the box with the BMI" mean? 182kg? and BMI ?

Can homebuilders buy them from any supplier?, or do you need to be a manufacturer?

Intrigued

First of all:
Both Zebra battery and lithium batteries, are needed on the market - so this is not direct competition. Its characteristics and features are quite different so there are customers who will be really satisfied about these batteries.

About the Zebra battery:
I have had few inquiries from customers wanting to replace their Zebra battery pack with lithium-iron-phosphates. These batteries need to work in hot environment (about 300 Celsius as far as I remember). Customers told me that they have left the car for some time and batteries just died and need to be serviced.
In the beginning I was also thinking about installing these batteries in my cars, but now I am convienced that LiFePO4 are better.