[RE-wrenches] Lithium Ion Phosphate for grid back up

[Dan Fink]

Dave;

The way modern high-performance electric vehicle manufacturers are able 
to wrest such awesome performance out of Lithium batteries of any type 
is by using extremely sophisticated battery management systems (BMS). 
Per-string and per-cell monitoring *and* control is not uncommon, and 
temperature is also critical (note the battery bank cooling system in 
the Tesla Roadster). Also note that these sophisticated monitors and 
controls also extend to discharge, not just charging.

I don't think you'll find many commercial balance of system components 
that can deal with Lithium battery technology of any type right now, 
outside the EV world---and they aren't trying to make household 120/240v 
AC in an EV.

It would be a fascinating, exciting and challenging project to try -- 
but i wouldn't offer a warranty of any sort, on *any* of the system 
components. Also note that with Thundersky your tech support would be 
coming from China.

Dan Fink
Executive Director;
Buckville Energy Consulting
Buckville Publications LLC
NABCEP / IREC / ISPQ accredited Continuing Education Providers
http://www.buckville.com/
info at buckville.com
970.672.4342 (voicemail)
970.373.1311 (fax)



Dave Palumbo wrote:
> We have a potential client for a net metered PV with battery backup 
> system with a serious interest in using lithium ion storage batteries. I 
> do not know of any systems that have used these batteries yet. From some 
> quick calcs I come up with 105 LiFEYPo4 3.2 volt cells. 7 strings of 15 
> cells for 700 AH at 48 volts. Price is quoted at $ 125 per cell.
> 
>  
> 
> Here’s a link the client forwarded from his research.
> 
> http://currentevtech.com/Lithium-Batteries/Thundersky/Thundersky-40ah-cell-p24.html
> 
>  
> 
> What are the reasons why these are not being used in home power systems? 
>  The web site states 3,000 cycles at 80% DOD vs. 750 cycles for typical 
> gel storage batteries.
> 
>  
> 
> Also, what are your favorite inverter(s) for grid tied with battery backup?
> 
>  
> 
> David Palumbo
> 
>