Ypedal said:
Winter has arrived, ( 0 celcius this morning.. i wussied out and took a cab to work
)...
BUT.. i'll be giving those LifeBatts a go in 2008 !!! 72v 10 ah !
You have to look past the " Per Cell Cost " when you consider BMS, Charger, ABS Enclosure, and a warrantee. included and shipping !!!! those things have value to consider !
I'm sitting on 3000 $ of Lithium right now.. none of wich perform as good as i expected.... how wasteful is that. This is why i'll be waiting for reviews and details to emerge from independent testers before i buy in.... some more.
The LifeBatt -First impressions and initial testing -bob mcree 10/10/07
I am setting up a power-assist system for Jim Parker of Cruzbike. I will be using the LifeBatt on my bike for some real world testing this week, and the final version will be on his bike soon.
Some test data is attached, and more will follow. My initial impression of the cells is very good. They really can deliver 20C (200A) at about 2.3V and will deliver over 10 Ah @ 2C.
When we discussed batteries a couple of months ago, the LifeBatt was the only complete LifePo4 battery system available to order, and the 3 year warranty makes it seem like a good choice for someone who is very serious about getting the best battery performance possible and the best cost/benefit analysis. $1005 is a lot of money for an ebike battery, and 36v 10 Ah does not sound like a lot of battery; unless you have tried to buy batteries lately and expect to use your bike every day for years. I just got the first LifeBatt 36-10 in North America last week, for Jim's bike. The price includes shipping, 4 amp charger, and a 3 year warranty.
I do not work for LifeBatt or have any connections with them at all. Jim bought the pack and had it sent to me for initial testing and integration with a motor system I have for him. The pack dimensions and weight we were originally quoted turned out to be off quite a bit, but that can easily happen with a new product. The battery assembly has large bms housings that make it a couple of inches thicker than we expected, making us rethink our original mounting ideas. I am working with a prototype pack with no bms they sent me for testing, and this week we will be getting the final version of the pack with the bms.
The first photo shows the pack next to a 36v 12 ah sla rack pack. The 29 lb. sla would deliver about 1/3 less power than the 19 lb. LifeBatt, but mounting the larger battery might be a bit difficult on many bikes. The substantial molded case is modular so the cells can be stacked in rows and columns and bolted together, so it seems like one possible solution will be to split the 36 – 10 pack into two 18v packs and mount them in panniers that way. This would provide better balance and still leave some space in the panniers for cargo.
The next picture is a graph of discharge at 20A. The discharge curve stays above 2.5V for about 90% of the rated capacity, but 2.1v is their spec for low cutoff, along with 4.0v for high cutoff. I believe the bms will have an output for the ebrake signal on a typical controller, and an audible low voltage alarm.
:wink: Spend the cab fare on some warmer duds. 
