[RE-wrenches] PV excellent battery charger

[R Ray Walters]

MPPT doesn't really do that much for the battery, it just makes the PV modules more effective.
The real magic is: 
A) the 3 stage charging (compared to traditional single stage AC chargers)
B) Temperature compensation
C) PWM that helps pulse off sulfation
D) Slower charge rates let batteries charge more fully without damage from overheating.

R. Walters
ray at solarray.com
Solar Engineer




On Mar 24, 2010, at 7:04 PM, drake.chamberlin at redwoodalliance.org wrote:

> Can anyone tell me why PV is considered an excellent battery charger? I
> think it is, only after the addition of a MPPT charge control.  Otherwise,
> the battery drags the PV voltage below Vmp.
> 
> One of the NABCEP objectives for the entry level class is to explain why
> PV modules make excellent battery chargers and show this through the IV
> curve.
> 
> Thank you,
> 
> Drake
> 
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