Victron MPPT 75/15 with a DC power supply to charge a car battery

[@bobf.7238]

I wanted to do this but then, in the manual, I read the following. Quote; "Avoid using the solar charger as a DC-DC charger (e.g., to charge a 12V battery from a 24V battery bank). Connecting a battery to the PV terminals under certain operational conditions can damage the solar charger, which is not covered by the warranty. Instead, use a dedicated DC-DC charger or converter. Check our DC-DC converter product page for a complete product range". I read elsewhere on the Victron site that under certain conditions, the charger will short the PV input with an internal relay. It said that this is OK with solar panels but not with a battery or power supply. See section 8.12.10 through 8.12.12 of the Victron MPPT Solar Charger Manual. The smallest DC-DC charger is to big for my space so, instead of connecting my 12 Volt lithium house bank to the PV input of my Victron MPPT, I used a $14 "short protected" DC-DC step up converter from Amazon in between. So far, so good. This also satisfied the requirement that the PV input be 5 Volts higher than the battery to start charging.

[@bigrob1887]

This definitely doesn't work for the Outback Flexmax 60 charge controller. Don't ask me how I know....$$

[@fraziersingo5056]

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