this is one of those products aldi has intermittently.  I bought one two
years ago and have found it to be very good quality and a great price.
measuring its output to a fairly discharged battery it appears to first
charge at up to 4 amps and gets the battery up to 14.5V, then will drop to
2.5amps, .8amps and finally goes to a trickle charge at about .1amp.  You
can also set it to "motorcycle" instead of "car" and it cuts out the higher
charging current.  If the battery is not very discharged it will quickly go
to lower current output.  as it says in the ad it has a feature that is
supposed to revive a bad battery.  I have seen it go into this mode when
the initial V of a battery is somewhere below 11V or so.  I'm not sure I've
ever seen that actually work though.

On thing to note is that after a power failure or disconnect you will need
to press the button to turn it back on.  So if you have this maintaining
the house or starting battery in your vanagon you'd need to check it
periodically to make sure it's still "on."  Also, the display doesn't give
much detailed info about the charge state of the battery or what it's doing
but you may not need that anyway.

https://www.aldi.us/en/weekly-specials/aldi-finds-for-
november-1/november-1-detail/ps/p/auto-xs-car-battery-charger-2/

Edward