Gen 3 Prius. Need DC to DC Converter?

[teverz]

I own a Gen 3 Prius and looking at adding a Lithium 200ah batter to run my fridge and other things. I am going to install a

Blue Sea Systems Automatic Charging Relay between my AGM and the new Lithium so that the system will run independent but charge through the cars Inverter. Since the Rrius doesn't have an alternator , does this mean I still need a DC to DC Convertor? When I test the volts on the battery while the car is running it reads 14.1v​

 

[snoobler]

Welcome to the forum.

Gen3 charges at 14.X and floats at 13.5V once the battery is fully charged.

The inverter/converter does the job. 70A total current including car's needs. Note that it's a very inefficient "generator" spinning 1.7L of engine to produce a little over one horsepower of 12V charging.

 

[teverz]

Welcome to the forum.

Gen3 charges at 14.X and floats at 13.5V once the battery is fully charged.

The inverter/converter does the job. 70A total current including car's needs. Note that it's a very inefficient "generator" spinning 1.7L of engine to produce a little over one horsepower of 12V charging.

Thanks for the hello!!
As far as I know, The Hybrid battery charges the 12v. The car doesn't have a alternator, so the generator charges the Hybrid and then goes down the line. I could be wrong. So Then I don't need a DC to DC converter.

I am all new to this. I know an alternator doesn't put out enough V to properly charger a Lif Battery and was a hard time finding the answer to this. I have found others who put a second AGM in their vehicles but no Lif ones

 

[snoobler]

The 12V charger is a DC-DC converter located in the Inverter assembly. It is pretty robust and charges from the HV system (battery and MG1).

Provided the charger output is consistent with the AGM charge requirements (14.XV & 13.5V float), I wouldn't bother with a separate DC-DC converter between the batteries.