Yes, it is....or soon will be.

I know who’s distributing the line here in Hawaii and am trying to find out 
what's going for the rest of the U.S.
marco

Thanks Marco, very impressive product. I like the idea of redundancy per module 
so if a cell fails, only that one module will shut down. I can build that now 
with multiple CPU’s with our GBS line but after looking at the EU street price, 
I can’t match the value. But, I don’t see it available in the US, only in EU. 
Do you know if it is available for US market?

Larry


On Aug 18, 2015, at 11:28 AM, Marco Mangelsdorf <ma...@pvthawaii.com> wrote:

Sony is now producing an impressive LFP battery.

Attached is the spec sheet.

marco

Hello Peter,

Panasonic does not make lithium iron (LFP or LiFePO4) batteries, theirs are 
Lithium cobalt oxide (LiCoO2). Because RE system commonly have multiple charge 
sources, I think LiCoO2 is not as suitable due to the poor handling of over 
voltage events. Lithium iron phosphate (LFP) are far more overcharge tolerant 
and readily available in high capacity cells. Another problem with using LiCoO2 
cells is they require 4.2V/cell to charge making it a difficult fit with common 
RE equipment.

Each manufacturer has recommended charge profiles. It will be difficult to 
follow these unless the battery is disconnected from loads while charging.

For all Lithium batteries, the discharge rate is many times greater than would 
ever practically be used in a RE system. Most can be discharged at 3C and surge 
up to 10C. A 20kWh bank could supply 60kW continuously. Don’t try that with 
your LA battery!

Low voltage disconnect is (or should be) built into any LFP battery system as 
permanent damage can happen instantly. I recently had to repair a LFMP 
propulsion battery system (not designed by us) that was over discharged one 
time. It cost $6000 for me to make the repairs and install the protective 
solenoids. The Battery manufacturer had warnings in their installation manual 
against not using proper LVD but the builder skipped that part.

Magnum Energy has a come out with a CC/CV profile that works well with LFP 
batteries but it’s still not the needed profile. There are many differences and 
factors to be addressed for the RE industry. One hurdle to overcome in RE 
applications is that varying loads are applied while charging. A proper LFP 
charger will vary the power during the charge cycle but has no way of knowing 
that loads are present. That creates a real challenge for equipment makers but 
can be resolved by designing CAN interface and software that communicates with 
chargers and control CPU’s to make the adjustments on the fly.  

Larry Crutcher
Starlight Solar Power Systems


On Aug 18, 2015, at 8:31 AM, Peter Parrish <peter.parr...@calsolareng.com> 
wrote:

I too am interested in LiFeP batteries. I think we need some more information 
on charge/discharge cycles. I’ve bits and pieces, but there must be some solid 
data from Panasonic or one of the other LiFeP manufacturers. Such as,

Recommended charge cycle
Maximum discharge rate
Low voltage disconnect

Also I expect all of the CC manufacturers are thinking about LiFeP or similar 
Li technology. Maybe if one of us has a friend at Outback Power, Morningstar, 
Midnite Solar, we could find out more.

-          Peter


Peter T. Parrish, Ph.D.
President, SolarGnosis
1107 Fair Oaks Ave.
Suite 351
South Pasadena, CA 91030
(323) 839-6108
peter...@pobox.com




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