Battery upgrade and solar controller

[pyuan]

I have a Forester 2021 with a solar panel. I am considering upgrading the lead battery to a Lithium battery. The battery is charged by 3 ways: power converter with Li mode, generator from the truck through BIM, and solar panel probably thru solar controller. I can find a Lithium BIM with the same foot print, but I cannot find the solar controller in the RV. Do you know where the controller is located?

I have a Tracer Meter MT-1 on the wall, but it is only a meter.

 

[bikendan]

Moved thread from the Tech and Repair section to the Motorhome section's Forester and Sunseeker sub-forum since the OP is asking for model-specific information(solar controller location) and for better help from other Forester owners and possible factory support.

 

[Aussieguy]

If you don’t find it that should not be a drama as the wiring should be in place

you can use the tracer meter screen to change the settings to liftpoe4

Look for the online manual if you don’t know how to change settings

Cover the solar panel before taking out the batteries and uncover after battery swap just incase solar controller is sensitive to not having a battery,
some don’t like it


It would be good to locate the controller do you can update the panels to the maximum the controller can accept

1 panel depending on size will keep the house and chassis battery charged during storage
If you want new battery to be charged while camping more panels will be required

I would maximize the panels to suit the controller you already got leave it in place

If you want more panels
work out how many more panels you can fit up on roof and add a second string with its own wiring and controller

Get the wattage of the string and divide it by your charge voltage
800 / 14.2 =56 buy a 60 amp controller

Wire that to house battery
You can add as many charge controller upto the maximum the battery bank can handle
Consult battery manual

 

[TacomaJoe]

I have a Tracer 3210AN controller with a MT50 display. My controller doesn't have LFP settings but does have a USER option that can be used with custom voltage settings. I can make all the changes with the display buttons and the controller is buried in with my batteries.

I'm not sure if the MT1 let's you change the charging profile.

 

[laprez]

I have a Forester 2021 with a solar panel. I am considering upgrading the lead battery to a Lithium battery. The battery is charged by 3 ways: power converter with Li mode, generator from the truck through BIM, and solar panel probably thru solar controller. I can find a Lithium BIM with the same foot print, but I cannot find the solar controller in the RV. Do you know where the controller is located?

I have a Tracer Meter MT-1 on the wall, but it is only a meter.

I can only tell you my experience with my Sunseeker 2022. The controller was under the fridge on the entryway wall. Was not easy to get to. It was a dual controller, feeding both battery banks. It did not have a Li setting. The only replacement with a Li setting I could find was a 20 A Victron, with dual battery capabilities.

 

[Aussieguy]

If it has user defined you just set the voltages to 14.2 & 13.6 float

I prefer that than the cheesy way try hey setup their lifepo4 settings
They wanted battery to go to a lower SOC before starting to charge from the solar… stupid idea as it may not reach that voltage fore several hours and you loose valuable charging time!

 

[pyuan]

Thanks. I found the solar charge controller! It is under the kitchen sink and casually fixed to the floor with one screw. It was blocked by the hot air hose and I did not find it in the first time.

It is an old version EPEVER dual battery controller. The first battery output port is connected to the coach and the second one is connected to the chassis battery. The MT-1 meter is connected to it with a RJ45. I checked the newer version of EPEVER controllers. It seems they are not compatible to LFP batteries. Do you have a dual battery controllers in mind? Thanks.

 

[Aussieguy]

here is one it's a mppt maybe bigger than your original

Amazon.com

you could move it if you cant fit it under sink get it closer to battery
its 30 amp and can do a max of 400w solar

Battery 1 is house and can be lithium
battery 2 is lead acid (starter type)

 

[pyuan]

Just realize: the power converter and solar charge controller are connected to the coach battery directly. If we use a single channel solar charge controller, it will charge both batteries like the power converter with the Li battery output option: the Li coach battery is charged directly, and the lead chassis one is charged through the Li-BIM. Is the charging profile a problem for different batteries?

 

[Aussieguy]

the BIM or newer LI-BIM is just a relay with some logic circuits
that allows the house and chassis batteries to be connected in parallel....
then when they are connected then both get charged...
because they are now paralleled as one big battery

Li-bim was re-designed to stop the lifepo4 from putting too much strain on alternator
it use a timer to disconnect the batteries after 20 minutes ...
then reconnect after alternator has cooled down

The brains ... of the system looks to see if any of the batteries are getting charge voltage (whatever the source)
and............. if the batteries need to be put into parallel so they can all charge at same time
such as .... when alternator is charging the chassis and the HOUSE is a bit low... it will decide to allow the LI-Bim to parallel the two together

clear as mud ...right?

 

[Aussieguy]

PS solar charge controller

you can have as many charge sources on the battery as you want
(within reason)

so adding a solar controller to any of the batteries is not a drama.
the controller and battery will decide what needs to happen just leave them on and let them do their work.

only turn off for maintenance