This and several other smart chargers can be found on batterystuff.com.
I have no financial interest in the web site nor any products found there. Furthermore, contrary to rather unsavory comments, until a few months ago i had never heard of progressive dynamics.
I do not advocate any specific product, though i have purchased one. I do advocate attempting to follow the battery
manufacturer's charging instructions, which requires learning a very minimal amount specific to the batteries i buy.
And finally, if you already own and regularly use a smart solar
charger, you probably have no need for anything more to correctly maintain your batteries. It pays to check however. You want as many of the following as you can get:
1) 14.8 v bulk charge
2) Charge current sense controlling when the charger switches charge modes.
3) Temperature compensated charge current. This is not an issue for low current chargers.
4) Voltage sensing at the battery
controlling the charger output voltage
5) Charge voltage curves modified for wet cell, agm and gel batteries.
Just because a charger claims to be smart doesn't guarantee it provides all the above qualities. The manufacturers know that these things are important and tend to proclaim loudly those things that they do provide, making it pretty easy to discover those which they do not provide.