upgrade converter/charger on 2015 Keystone Passport 2920BH?

[FreeFromCube]

First time poster! :-)

I bought a 2015 used 2920BH in the fall. It's in storage now, but I'm planning out a battery upgrade, and potentially solar. It currently has a single 12V battery, and I plan to upgrade to 2 x 6V 200+ Ah deep cycles connected in series. I don't plan to do long term boondocking, just occasional overnight unserviced stop while on the road and my plan is to have fresh water and full batteries to make the stop more convenient.

Does anyone happen to know what the converter/charger is in the trailer? If single stage, what are good options to upgrade to multstage? I'm guessing what is there isn't great for larger 6V golf cart batteries.

I'm also looking at some solar and charge controller, but that's for another day :-)

Thanks!
Mark

[FreeFromCube]

Also, how does it work if there are numerous chargers in the system? 1. Trailer factory single stage converter charger, 2. Solar charger, 3. and I was thinking of leaving the trailer factor charger and just adding a smart charger like NOCO genius G7200 multi stage charger connected to the batteries. Will the chargers fight each other? Will the smart charger try to maintenance charge when full while the trailer's converter/charger keeps pumping? I'm confused how this all works and how the batteries are actually charged with multiple chargers on the system. Thanks for any help!

[Brentw]

Hello, don't know what is in you unit, but I would dig up the model number and Google away, ideally you are looking for a multi stage charger, it will treat your batteries better.
As for adding a charger, pretty sure the one with the higher voltage will shut down the other, chargers use voltage as there indicator of battery charge and adjust amps accordingly.

[FreeFromCube]

Hello, don't know what is in you unit, but I would dig up the model number and Google away, ideally you are looking for a multi stage charger, it will treat your batteries better.
As for adding a charger, pretty sure the one with the higher voltage will shut down the other, chargers use voltage as there indicator of battery charge and adjust amps accordingly.

Thanks, yes I did Google search but couldn't find any details. I think it's safe to assume it's a basic single stage charger in the converter.

Regarding chargers and voltage, this is my concern. I don't know enough about battery charging but I'm wondering if multiple multi-stage chargers will cause problems fighting between modes like bulk charging vs float. I'm guessing that having both single stage charger and multi-stage would be a problem.

[flybouy]

If you post the model numb of your converter someone will tell you what you have. I'd suspect it's a 45 amp 3 stage charger, pretty much standard on campers for several decades. More than one charger will not work as the voltage of one charger will satisfy the other charger as battery charged and it will shut down.
If you search the forum you'll find many posts on this.

[JRTJH]

Your trailer probably has a WFCO 8945 or 8955 power center. Both contain a converter/charger that serves to provide up to the rated power (45 or 55 amps) with the remaining power available for 3 stage battery charging. You can download the specifications, owner's manual and troubleshooting/technical information here: https://wfcoelectronics.com/product-category/power-centers/wf-8900-series/

Your question about multiple chargers has already been answered: No you can't use multiple chargers. The reason is because almost all "automatic chargers" (ones that have multiple charging phases) are voltage driven. As the battery voltage increases, the charge rate (from the charger) is decreased to prevent overcharging the battery. So, if you have two chargers connected to the battery, the "line voltage" will be the output of (pick one) charger which would be "monitored/sensed" by the other charger and act as the means to reduce charge power from that charger.

So, if you have a 55 amp WFCO converter/charger in your trailer and you connect a "cheap 1 amp HF trickle charger" to the battery, the 13.4 volts from that HF charger will "tell" the more powerful WFCO that the batteries are fully charged and force it into the "float mode" (trickle charge mode) which would prevent your battery from adequately charging.

In other words, one battery charger will "fight" any others that you might connect, making it impossible to charge your batteries from multiple chargers. That's why any "professionally installed solar/battery/multiple charging system has automatic or manual switches to remove all but one charger from the battery feed.