2nd battery bank addition to 2318esp with go power GP-PWM-30-UL

[Tony2318]

I have a 2318ESP with a Go Power GP-PWM-30-UL solar controller.

I have a battery bank with two 100W LiFePo batteries running in parallel. I want to add a second battery bank with some 12V AGM batteries that came with the trailer when I bought it.

I read the manual for the gopower and I know how to add the 12V batteries so they get charged but I’m wondering if I need to add a second fuse and battery disconnect under the trailer?

Also do I need to set up a way to switch from one battery bank to the other or does the go power automatically switch between the two for power? I know it will charge the second bank after the first bank is full, but how does it utilize power from the second bank?

Last question. I have room on my tongue for a 3rd 12V battery (the AGM for the second bank) but I’m wondering if I can set up a fourth battery, a second AGM, by connecting it externally, somehow in parallel to the first AGM battery for the second bank.


Thanks!

[nvs4602]

You can't mix lithium and lead acid or AGM. All 3 have different charge settings. The go power controller should be set to lithium charge settings. You would have to change these parameters each time you switch between banks.

[bikendan]

Moved thread from the Modifications and Updates section to the Electrical, Charging Systems and Solar sub-forum since the OP's questions are specific to that sub-forum.

Sent from my SM-G781U using Forest River Forums mobile app

[PhilFromMaine]

Originally Posted by nvs4602

You can't mix lithium and lead acid or AGM. All 3 have different charge settings. The go power controller should be set to lithium charge settings. You would have to change these parameters each time you switch between banks.

Certainly that is the conventional opinion. What I recommend is setting up a battery disconnect switch like this 3 way switch. Of course to be absolutely correct, you would have to adjust your controller also to the correct setting and to me that is not a big deal.
https://www.amazon.com/Blue-Sea-Syst...95&sr=8-3&th=1

[Aussieguy]

It's possible to do will need some switching as per Philfrom Maine

You'll will probably make a system that requires more vigilance for LITTLE gain
I would leave it to the experts who like to play around with that sort of stuff.

You want a power system that is easy to use and understand.

If the AGM batteries are still relatively good sell them and use the funds towards more panels and a better controller.

Your GP-PWM-30 indicates you probably have a basic factory setup that could benefit from some tweaking...

Spend your time and $$ on the panels and controller, your 200ah battery is a good start.

[GolfingDave]

Looks like you can per GoPowers instructions, see link at bottom. May want to do this if you have a starting battery along with the rv batteries?? Or as the OP is trying to do.

Setting Battery 1

To set the battery type for battery bank 1, hold the B Button for 3 seconds. When the display shows a blinking number 1, release the B Button.

Next, select the charging profile of battery bank 1 by pressing the B Button to toggle through the profile options: Sealed/Gel, AGM, Flooded, or LFP.
To confirm the battery profile, press and hold the A Button for 3 seconds.

Setting Battery 2
If you have a second battery bank connected, the controller will immediately prompt you to set the battery type for Battery 2 with a blinking number 2.

If there is not a second battery bank connected to the controller, or if the second battery bank is connected with reverse polarity, the controller will not prompt you to select battery type for Battery 2, and no status information will be displayed on the LCD screen.

To select the charging profile of battery bank 2, press the B Button to toggle through the profile options: Sealed/Gel, AGM, Flooded, or LFP.

To confirm the battery profile, press and hold the A Button for 3 seconds.

Non-volatile memory: Any settings made on the GP-PWM-30-UL will be saved even when the power has been disconnected from the controller.


https://support.gopowersolar.com/kb/...rging-profile/

[itat]

The OP may already have this information but their particular GoPower PWM solar controller can be connected to two separate battery banks.

https://support.gopowersolar.com/kb/...iring-diagram/

[Aussieguy]

Originally Posted by GolfingDave

Looks like you can per GoPowers instructions, see link at bottom. May want to do this if you have a starting battery along with the rv batteries?? Or as the OP is trying to do.

Setting Battery 1

Don't forget the 120v and converter may need to be connected
probably just add a second separate charger

but connecting 2 battery banks to power the trailer needs some extra thought.
simply allowing the 2 different types batteries to parallel when connected to the power center is asking for problems.

You want a selector switch to 1-2-Off and NO combine so the banks will not be combined Unless you are a electrical guru and knows how to connect and limit current between banks.

asking the 30amp solar controller to charge 2 banks
how much actual power is being produced on a given day?
how much power is being sent to each bank?


If a factory setup with let's say two panels 10 amps per panel....
you'll only see MAX in perfect conditions about 20amps

check with the controller...... on how it splits that power between banks you only get 10amps per bank.

to me that's going backwards.. the Lithiums can accept way more amps and charge better on solar.


the money and time spent on getting the older batteries tech to work would much better be spent on improving the charging of the new Lithiums.

You will get much better results and a simpler system , less weight and not having finding a place for the extra battery storage.... especially since the OP has a popup with very limited storage.

The 2 lithiums will be more than enough for average smaller camper that only camps on weekends and maybe one or two long trips a year.
even with the 12v fridge (if applicable)

[Giboneys]

I think that by the time you add the extra wiring, fuse, disconnect switch you would be better off selling the AGMs and adding a extra Lithium and possibly a solar panel. How many panels do you have on the roof now and are they the standard 190W from the factory. If you only have one solar panel you can add two more to the controller you have as long as they are the same 190W from the factory (that is from GoPower) that is what I did. I also added a 200W portable panel from Renogy with the built in charge controller to the port on the side of the trailer, with a solar extension controller I can move it away from the trailer out of the shade. If you go with a portable panel make sure your port on the side of the trailer polarity is correct, mine was reversed.