[RE-wrenches] 4 ways to keep a battery for a long time

[Ray Walters]

Hi Larry;

LFPs definitely have some internal resistance and therefore are subject 
to Puekert's law, they just have an exponent that is closer to 1.  Yes, 
they also have a higher operating temperature, but it still has a limit.

My point is that if you develop software to better model FLA batteries, 
the software could easily be adapted to other technologies by simply 
inputting the appropriate Puekert's exponent, temp limit, etc. of that 
particular battery.

R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760

On 12/18/2015 8:44 AM, Starlight Solar Power Systems wrote:
> On Dec 17, 2015, at 11:55 AM, Ray Walters <ray at solarray.com> wrote:
>
> ...but as far as I can tell, every other storage chemistry has similar characteristics: lower capacity at low temps, a high temp limit, non-linear cycle life depending on DOD,  Puekert's exponent relating capacity vs charge/ discharge rates, volt drop under hard discharge, etc.
>
> R.Ray Walters
> CTO, Solarray, Inc
> Nabcep Certified PV Installer,
> Licensed Master Electrician
> Solar Design Engineer
> 303 505-8760
>
>
> Exception: LFP batteries are not affected by Peukerts Law. Discharging at 3C or .3C has little effect. Also, high temperature degradation rate quite a bit lower than that of lead batteries.
>
> Larry Crutcher
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