LiFePo4 - current and future users

lestef

Hy all,

I create this topic for those who already use this tehnology to power their systems and for the future users who want to learn about this.
There are lot of comparisons between LiFePo4 and another type of battery, but this will be a discussion about the real experience, manufactures, places to buy, management systems things to know, and others...
This week I will make an order for 48 V 160/180 Ah battery bank from here: http://www.ev-power.eu/index.php?cur=1& , and I have some questions :

1. The same old one... Calb or Winston ?
I read a lot of discussions about LFP and I have noticed that many prefer the new gray Calbs instead of other brands, but also I found that the Winston lifepo4 will extend its life cycle by using yttrium in their chemical composition.
For my system I don't need big discharge currents where Calbs have better results (evtv), the only parameter that I consider is the life of the cells...

2. BMS – real importance for RE systems
What you think abou these: A RE system is very different from an EV system in terms of the need for a BMS. In a RE system you are not handling the extreme high currents that occur in an EV battery. Also, if you get balanced, large prismatic cells, and stay within the "knees" of the charge curve, you won’t need to use a BMS.
I consider that the BMS is important to be there in place, but for start I want to invest all the budget for a larger capacity, make it work, and then buy a BMS like this which is not the cheapest one: http://www.ev-power.eu/BMS123-System/?cur=1

3. Is anyone who knows another good places to buy on the european market ?

My actual system - 3 kW PV array, Studer XTH 8000 inverter, and Flexmax 80 charger.

Have a sunny day !

karrak

Re: LiFePo4 - current and future users

lestef wrote: »

1. The same old one... Calb or Winston ?
I read a lot of discussions about LFP and I have noticed that many prefer the new gray Calbs instead of other brands, but also I found that the Winston lifepo4 will extend its life cycle by using yttrium in their chemical composition.
For my system I don't need big discharge currents where Calbs have better results (evtv), the only parameter that I consider is the life of the cells...

I have the Winston LYP cells which I have been very happy with. The only problem is that I have only had them for around 19 months so cannot say how long they are going to last although from the research I have done I think they will last more than ten years. I agree with your conclusions about the two brands of batteries. the LYP cells are also supposed to work better at low temperatures. This tread http://www.thebackshed.com/forum/forum_posts.asp?TID=902&PN=3&TPN=1 and http://www.thebackshed.com/forum/forum_posts.asp?TID=1127&PN=3 and http://www.thebackshed.com/forum/forum_posts.asp?TID=2790&PN=1 and http://www.thebackshed.com/forum/forum_posts.asp?TID=5991&PN=1 documents one persons experience using the old Thundersky/Winston LFP cells from 2008 in an EV and then putting them on his solar system in 2013

2. BMS – real importance for RE systems
What you think abou these: A RE system is very different from an EV system in terms of the need for a BMS. In a RE system you are not handling the extreme high currents that occur in an EV battery. Also, if you get balanced, large prismatic cells, and stay within the "knees" of the charge curve, you won’t need to use a BMS.
I consider that the BMS is important to be there in place, but for start I want to invest all the budget for a larger capacity, make it work, and then buy a BMS like this which is not the cheapest one: http://www.ev-power.eu/BMS123-System/?cur=1

I think that a BMS of some sort is very important, especially for a 48 volt system. See my experience here http://forum.solar-electric.com/showthread.php?19472-Precautions-to-take-with-LiFePO4-batteries. If you can't afford a full BMS which will disconnect the solar panels in the event of overvoltage on any cell or disconnect the inverter in the event of low voltage on any cell at least get something like the Cellog 8s to give you an alarm. Unfortunately the Cellog 8 has some flaws that are discussed here http://endless-sphere.com/forums/viewtopic.php?f=14&t=20142&sid=81995a49329687e13f11aee915bb013a If you do use the Cellog8s let me know and I can give you more information.

From my experience the most important thing is to make sure that the cells are all balanced before you use them, this in MOST IMPORTANT and can save lots of problems later on. Don't rely on the supplier doing this properly.

Hope this Information is of use.

Simon

gww1

Re: LiFePo4 - current and future users

Karrak
Very imformative post.

lestef
I create this topic for those who already use this tehnology to power their systems and for the future users who want to learn about this.

This is the second time I have seen a poster try to control the content of a lipo thread in an open forum. If you are posting for "future users who want to learn" You can't leave out all portions of the discussion by only listening to poeple who are already supporting a decision that they have already made. That becomes more of just a promotion of something rather then "learning about something" I hope you get the info you ask for on your first post and also hope that the many smart people that have construtive imput (whether owners of these batteries or not) provide that imput so that "future users can learn" as much as possible before making that future decision.
Cheers
gww

westbranch

Re: LiFePo4 - current and future users

I read with interest about the VW van conversion yesterday and sent off an email to the driver of the VW...

He told me that they presently use SLA batteries and are going to Boston Power Swing Li -ion batteries... Went to the SWING site and it is devoid of much tech info but I did find this info about their Prismatic cells... Note the BOLD section.
Possibly LiFeMnPo4??

http://www.boston-power.com/applications/transportation

You are here: Markets › Transportation
Lithium-ion Batteries for Transportation: Electric Vehicles (EVs) and Small Task Oriented Vehicles

Boston-Power's lithium-ion battery technology platform was specifially designed to be optimized for the extreme conditions and challenging use cycles of the automotive market. The Swing RESS is the most advanced rechargeable energy storage system (RESS) available for the transportation market today, allowing our partners to offer a market-leading, long range EV driving experience.

Industry leading system performance:

Highest energy density with long cycle life
10 year reliable calendar life
Broad operating temperature range -40˚C to 70˚C (discharge)
Proven field safety record

Electric Vehicles

Our Swing® cells, blocks, modules and systems provide an optimal combination of dependable energy density and power for both distance and drive performance for long-range Battery Electric Vehicle (BEV) and Plug-in Hybrid Electric Vehicle (PHEV) applications.

The high energy density, long cycle life and power of the Swing Li-ion battery cells were designed to meet automotive industry performance targets such as USABC (United States Automotive Battery Consortium), SAE and ISO. This makes it an ideal solution for BEVs and PHEVs, ranging from small sedans to luxury performance vehicles all the way up to Light Commercial Vehicles (LCVs).

Specifically, our Swing cells can deliver 207Wh/kg of energy density, (more than twice that of the lithium iron phosphate and NiMH solutions available today), combined with pulse power of 1500W/kg (2 sec) and constant power of 440W/kg for improved vehicle acceleration – significantly exceeding both energy density and power targets for BEVs and PHEV-40s set by the USABC.

Small Task Oriented Vehicles

Since it was designed for high mileage electric transportation, our Swing line of products are also an ideal choice for smaller transportation-based applications, such as Small Task Oriented Vehicles (STOVs) and Neighborhood Electric Vehicles (NEVs). The high energy and long life provide outstanding performance and a reduction in operating and warranty costs.

Read the Q&A with Bob Purcell, electric vehicle pioneer and 30-year auto industry veteran, who spearheaded the launch of GM's EV1.

Contact sales@boston-power.com to learn more on how we can help with your application.

Lithium-ion Batteries for Transportation

Market Overview
Transportation
Utility Energy Storage
Portable Power
Government

westbranch

Re: LiFePo4 - current and future users

ADD: from an email from Boston Power battery chemistry:

Boston-Power manufacturers energy cells and our exact chemistry is confidential. We can go so far as to say it is a nickel based blend.