2021 R-27 OB solar controller location

[Red-27]

I am trying to find the solar controller on my 2021 with lithium batteries. I watched a youtube video by Channel surfing replacing theirs and was looking into upgrading mine as well. However their solar controller was located where my 60 amp charger is and is no where to be found. i tried looking everywhere i could think but the only thing i found was a drill bit someone lost at the factory.

Does anyone have any idea of the new location of the controller?

 

[Submariner]

You are looking for a black box that looks like a battery charger.

It looks like this, and I believe it's in the port lazarette.
https://www.kisaepower.com/products/dmt1250/

The RT27-OB LE with LiFEPO4 batteries requires an MPPT style solar controller. The charger RT is using is a combination 12 volt DC to DC charger. It has 2 inputs and 1 output. The output goes to the LiFEpo4 batteries. The two inputs's, one comes from solar, the other comes from the engine (indirectly, via an ACR that then goes through a voltage sense regulator).

Here's the write-up and electrical schematic.
https://www.letsgochannelsurfing.com/luxury-edition-lithium

I'm currently in search of an RT27-OB, LE that I can crawl around in to get more photo's and such of the LiFePO4 installation as I'm working on an electrical walk-through video of our boats.

 

[Submariner]

The Kisae DMT1250 supports up to 17.5Vdc for 12V PV solar panels connected in parallel. You wouldn't upgrade this controller as it's required for charging the LiFEPO4 house bank when underway, engine charging.

If you upgraded your solar, you would add a new MPPT controller that supports LiFEPO4 and that matches the voltage and amperage rating of the solar panels you're adding.

 

[bobmastors]

On my boat (2021 R-27 OB with lithium) the Kisae DMT1250 is located in the port lazerette opposite the thruster battery.
Easier to access from the center lazerette by crawling aft and looking to your right.

From reading the manual, it seems the DMT1250 only charges from one source at a time.
If the engine is running, it will provide the charging and the solar panels do not contribute.
I am thinking of adding a new Victron MPPT controller for the solar panels and keeping
the DMT1250 for engine charging.

 

[marksandyham]

Martin,
You are welcome to come crawl around my 2019 R-27OB

 

[Submariner]

Martin,
You are welcome to come crawl around my 2019 R-27OB

Thanks! It's the LiFEPO4 battery install I want to see on an RT27-OB.

 

[Red-27]

Those are helpful to see what i am looking for. ill look for it next time i am on the boat. this is a low priority project but one i would like to do.

 

[Submariner]

On my boat (2021 R-27 OB with lithium) the Kisae DMT1250 is located in the port lazerette opposite the thruster battery.
Easier to access from the center lazerette by crawling aft and looking to your right.

From reading the manual, it seems the DMT1250 only charges from one source at a time.
If the engine is running, it will provide the charging and the solar panels do not contribute.
I am thinking of adding a new Victron MPPT controller for the solar panels and keeping
the DMT1250 for engine charging.

Channel 2 (Solar array) supports up to 50VoC at 30amps max. This equates out to about 500 watts of solar with 12 volt panels (per the manual). 775 watts max using 24volt panels (in parallel only).

The two CMPP22200S (200 watt) solar panels I installed on my boat have a VoC of 38.9 (Nominal of 33 volts at 6 amps). They would work, however, they'd have to be installed in parallel, not in series. (Have to keep the voltage below 50 VoC).