Victron SmartSolar MPPT 100/15 Solar Charge Controller 100V 15A with Bluetooth

Q: Can controller be installed in battery compartment (somewhat limited in space). RV application, 2-6volt batteries, 1-100 watt panel.

Yes, as long as installation is not too close to batteries and the area is vented to avoid potential gassing / corrosion issues. And to allow for proper temperature sensing if the unit has only a built in sensor the controller should be is the same area as the batteries.

Q: Does this unit alternate voltage based on battery temperature?

The charger will compensate for temperature based on it's internal sensor, essentially gauging the local environment's temperature. An option Smart Battery Sense can be attached to the battery for true battery temperature. Those are new and in short supply, but should be fully available by the end of June, 2018.

Q: what is the difference between smart solar and blue solar?

The single difference between them is that the SmartSolar MPPTs have Bluetooth built-in so that you can monitor and configure them through the VictronConnect smartphone app. The BlueSolar MPPTs do *not* have the Bluetooth built-in; you can use a VE.Direct to Bluetooth Dongle to achieve the same functionality, but the cost of a SmartSolar ends up a little less (typically) than a BlueSolar MPPT +a VE.Direct to Bluetooth Dongle, so it usually makes more sense to order the SmartSolar. If you're not planning on monitoring the MPPT or changing any of the settings, however, a BlueSolar will be just fine, as the actual circuitry is virtually identical. Regards, -Justin Mobile Power Pros / Bay Marine Supply

Q: The item i received says 48v on the side. will it work with 12v/24v systems?

Even though the mppt has the 48V stamp, it will work with 12V 24V & 48V systems. The 48V is to differentiate it from the 12V/24V only mppt. Here is documetation from Victron showing it will work with all three Voltages. https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-75-10,-75-15,-100-15,-100-20_48V-EN.pdf