Sunday, Apr 08, 2012 at 15:16
Hi Johno,
you can use an alternator as a charging source for your house battery.
But
solar is a smarter choice in that it provides ample voltage, which isn't always true for car alternators.
Having said this, any car alternator will put 'some' charge into your battery.
Remember, alternators were designed to keep an almost fully charged battery full - they're not suitable to bring a reasonably discharged 'deep cycle' battery back to 100% full charge.
And never charging a battery to 100% means reduced battery life.
So you're asking what are MPPT
solar regulators:
these units basically convert voltage from the
panel to charging amps.
Ordinary PWM
solar regulators just provide a switching function between
panel and battery: either the
panel is connected (on) or disconnected (off), and the on/off happens rapidly, sometimes over hundred times per second.
This process isn't very efficient, because the
solar panel cannot output maximum charging power when directly wired to the battery (even for short times).
MPPT
solar regulators on average achieve a 20% higher charging power/current from the same
panel compared to an ordinary PWM
solar regulator.
Look for a multistage charging capable MPPT regulator, ideally with battery temperature sensor, and optimised charging algorithm. The latter enables the regulator to precisely charge the battery to 100%, regardless of any load drawing power during charging.
If that's not done precisely and correctly, the battery either gets over- or under-charged, shortening its life.
One word of caution: there are quite a few PWM
solar regulators being marketed as MPPT by unscrupulous Australian and overseas sellers.
To see a good example of a
well designed MPPT
solar regulator, just follow the link next to our logo.
cheers, Peter
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