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Comment by finnn | Hacker News Reader

This reminds me of a power box I built for Burning Man this year. The I had ~700W of solar panels, and in a box I put an MPPT charge controller, rather than the PWM charge controllers shown here, I had a 1kW inverter rather than 150W one shown here, but also tried to make most people in my camp use DC when possible, offering 2 USB plugs for each person in the camp, radio charging with a DC-to-DC converter, and a fuse box to prevent accidents. It worked out quite well, and we successfully ran a chest freezer and a number of other things off solar in the middle of the desert for a week.

Also, I used 2x100Ah deep cycle marine batteries + 2 additional batteries of unknown capacity, probably between 50 and 100Ah

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Does battery type matter for the charge controller? Just learning about the differences between deep discharge lead acid versus lithium in another thread - can the charge controller optimize for battery life of either type?

In short, yes. In my experience MPPT and PWM generally are used in similar situations, the difference mainly being in how they charge and MPPT "making the most" of the available power (which is why they tend to be more expensive) and charge the same types of batteries.

Both charge batteries using pulses rather than a constant voltage which extends the lifetime of the batteries compared to a cheap automotive charger that would over time reduce the capacity of the battery), all of which is geared towards lead acid.

Most PWM or MPPT charge controllers I've seen only support lead acid (which come in a variety of configurations, some vented some not) and do not do li-ion, at least not out of the box. Theoretically they have the hardware to do it (my CC can do 12v, 24v, and 48v systems) but maybe not the software.

Lead acid batteries have been probably the most commonly used in renewable energy projects for a while due to their cost-density but li-ion seems like a superior choice if you can front the initial cost. I've been looking at them but also feeling like in 5-10 years there might be more alternatives so replacing lead acid batteries every 5-10 years seems better for me at this point.

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