DC-DC Charger Topic in Tech Issues
I put a topic in the Tech Issues forum that may be of particular interest to TC owners, especially those with newer trucks with ECM controlled charging systems. I’m installing a Redarc DC to DC ba...
Forum Discussion
Batteries are fine with above 14V charging, as long as it is cut back when they are charged. They don't like above about 13.4V after they are charged. Most automotive alternators are set up with a low voltage so they don't ruin the start battery. The price for that is slow charging if the battery is in a low state of charge. I see many automotive alternators seem now to start at a higher voltage then cut back when they get warm - sort of a cheap and dirty 2 stage charge profile.
In boat where you live on DC power, the chargers are all 3 or 4 stage profiles: maximum current until absorption voltage is reached (around 14.4V for flooded cells), then voltage controlled at 14.4V cutting back current until the charge current is below a small value (say 2% of battery capacity), then dropping back to a float voltage (13.4V or so for flooded). This is both the fastest, and kindest way to charger your batteries.
It looks like the Redarc Dc-Dc charger is a three stage charger. Dc - Dc converters can be built that raise or lower voltage, or just keep it the same and regulated. Since your camper house battery is very often in a very different state of charge than the engine start battery, a charger like this makes a lot of sense - though 20 amps is pretty slow.
In boat where you live on DC power, the chargers are all 3 or 4 stage profiles: maximum current until absorption voltage is reached (around 14.4V for flooded cells), then voltage controlled at 14.4V cutting back current until the charge current is below a small value (say 2% of battery capacity), then dropping back to a float voltage (13.4V or so for flooded). This is both the fastest, and kindest way to charger your batteries.
It looks like the Redarc Dc-Dc charger is a three stage charger. Dc - Dc converters can be built that raise or lower voltage, or just keep it the same and regulated. Since your camper house battery is very often in a very different state of charge than the engine start battery, a charger like this makes a lot of sense - though 20 amps is pretty slow.
