can anyone recommend a basic battery to battery charger, thanks
Basic is the problem word here. B2B chargers aren't basic split charge relays. They need to be setup by you to suit the auxiliary battery you are charging. One of the settings is for charging voltage which you have to set. EG. If your leisure battery is maintenance free, then you set the charging voltage at 14.2v. (I can't remember but 14.2v could be the default setting.) Anyway, if you have a flooded battery, then you need to set the charge voltage at 14.6v.
In my experience, a B2B charger isn't the sole solution to auxiliary battery charging. Neither is a SCR or a VCR.
I did a couple of jobs early doors this morning. Used 4 amps from fully charged leisure battery. Drove 6 miles home. On the way back I only returned 1 amp to the leisure battery. The alternator was charging my battery at 4 amps on the way home. The fuller the battery, the lower the charge the battery will accept. So that charge rate will drop to 3, then 2 and then 1 amp.
If it remained at 4 amps charging rate, it would take an hour of driving to recharge what I used.
Since I purchased my BB1260, Victron have brought out their own B2B charger. What I like about the Victron one is that it can be set-up via an ap on your Android phone which is much easier.
