Connecting Batteries into Solar System

To clarify,
Trailer had two separate battery systems:

Original Trailer Battery Bank:
- 2x 12V AGM 92AHr in parallel (Marine Deep Cycle - Intimidators)
- Only connected to 12V systems
- Only charged by grid or generator through InteliPOwer Charge Wizard Converter/Charger 9200 Series

Existing Solar System - Missing Batteries
- Previous owner had 2x 12V AGM in parallel but took them
- I'm looking to replace these batteries or integrate with trailer battery bank
- Only charged by Outback FlexMax 60
- Only connected to Magnum 2800W Inverter - 12V in to 120V out
- Not sure if Magnum Inverter was used to charge these batteries


I would like advice on the best setup for full timing. We would dry camp 2-3 days traveling then stay at RV park 2+ days. We may have to use furnace 2-4hrs/night dry camping.
I'd like to new batteries to be able to power 120V and 12V systems.
I need to figure best way to charge batteries in any situation (solar, geny, inverter/charger from solar batteries).

And I'm still debating Flooded vs AGM. Looking for best budget options.

Thanks for all the help,
Tyler

I checked that the solar panels were each 48V (all in parallel) with a multimeter.

I'll take the original trailer batteries (12V AGMs) to auto store to test capacity. If they are good, I'll use them. If not, I'll replace those.

I could get another one or two 12V batteries and combine them with the old ones to make a single battery bank.  I'm not worried about reduced cycle life because I'm only trying for 1-2 years. I could find some used ones. It should not matter to mix AGM and flooded or mixed capacities. There's no space in the compartment with the existing batteries, and I'd have to ventilate the flooded batts.

Still trying to figure out how to use the geny to power just the AC alone and then use the batteries to power the rest of the 120V and 12V systems.

Once I get the status of the existing trailer batteries, I'll make up a circuit diagram for final input.

"Still trying to figure out how to use the geny to power just the AC alone and then use the batteries to power the rest of the 120V and 12V systems."

Why would not want to power the whole RV with the generator, when you are running the generator for the AC?

Only charged by Outback FlexMax 60

Click to expand...

(The missing 'solar' batteries)

This FlexMax is not a battery charger, it is a charge controller used to control the charging outputs of solar arrays. The charging voltage comes from the solar cells to charge the battery and the FlexMax takes the 48V output of the cells that you measured down to the appropriate 13.5-14.5V Voltage to charge the batteries. The remaining house batteries are charged by the Intellipower converter when plugged in or running the generator in your present arrangement as you stated.

http://www.outbackpower.com/outback-products/make-the-power/flexmax-series-charge-controllers/item/flexmax-6080

Should you wish to combine the banks of batteries so they will all serve the trailer and all be charged by all the charge sources available, they should all be the same type, AGM in this case.

I have to ask the same question as Paul....! But it would simply mean rewiring the output of the generator to go directly to the air conditioner alone. Using 12V to power 120V part of the trailer with an inverter is not really practical and a waste of time when 120V is readily available from the genny, not to mention the requirement for a BIG battery bank that would be needed to accomplish it. How big would depend, of course, on your need of electricity and an energy audit could aid in determining this.

Remember, solar energy along is NOT ALWAYS available or available in the quantity you may need to maintain those batteries. Shade, rainy days, clouds, have a nasty habit of getting in the way of "solar only" charging especially when other sources of charging are not available. You will have no flexibility.

My generator is a Champions 2800W / 3100W peak gasoline. A 15000BTU AC is pushing/exceeding the limits of the geny. I'm not sure the concequences of running AC and microwave at same time. I could manually operate one at a time, but it sure be nice to run the AC off geny and rest of 120V off batteries/inverter.

Why can't flooded and AGM be mixed? I'd probably find a used AGM if I combined battery banks, but I interested.

It's generally not good to combine different type and ages of battery together due to differences in charging requirements. Correct settings for one type may over or under charge a different type. Older, weaker batteries may pull down a good battery.

A 15K A/C, microwave and likely converter too is a big load on that size of generator. Altitude and heat can hamper the generator even farther. At least drop the A/C down to fan only before running the microwave. With the solar charging the batteries you could shut down the converter reducing the load even farther.

AGMs are expensive batteries, and to get the longest lifespan out of them, they need to be charged with a slightly different charging profile than "standard" lead/acid batteries. That's why our Magnum 2800 watt inverter/converter system (the same one you have) has different charging options for different types of batteries. Cycle through the menu and you'll see them. AGMs can be charged with a standard battery's charging profile, but they probably won't live as long. There's a reason for the different settings in the charger.

A battery with a higher AH capacity will, in all likelihood, take longer to fully recharge than one with a lower AH capacity. How much so depends on different things, like their condition, the actual difference in capacities, the type of battery etc. Our AGMs can accept the full 150 amps that our converter/charger is capable of putting out - up to a point. I don't know if other lead/acid batteries can do that. When hooked together, batteries of different capacities will "equali!ze" themselves, but the weaker one will always draw the stronger battery down - somewhat.

In your first post, you mentioned that you wanted to keep things simple, and in a later post, you said you were just trying to figure out the best way to boondock for 2 to 3 days while running your AC off your genset and the rest of your RV (including your microwave) off the inverter. It's your RV, but I'd recommend that you don't go down that path, because the only way to do it is to wire a new circuit for the AC unit that's independent of everything else. It would be far simpler to just turn the AC off for a few minutes while you're using the microwave, then turn it back on when you're done cooking.

I'll also repeat what I said in my first post - When boondocking, there are few good reasons to have independent battery-banks. It's almost always better to have a single battery-bank that's easily monitored with a good battery monitor. It sounds like you have good quality components, but unnecessary complexity in their design. Wiring the RV to enable the AC unit to operate off one power source, while the rest of the RV operates off another, will only make things more complex. FWIW

Kev

Today I finished the wiring to remove my battery from the tongue of the trailer. It felt so good knowing I don't have to worry about charging it and I'll put a tool box in it's place.

I added these links earlier, but looking back the URL's didn't stay with the posting.  These links will give you good info about RV electical stuff. 

Things like do I want to connect the solar and Magnum to the original house batteries.  Answers to questions like "Why can't flooded and AGM be mixed?"


http://www.jackdanmayer.com/rv_electrical_and_solar.htm
http://www.jackdanmayer.com/Batteries_and_charging.html
http://www.marxrv.com/12volt/12volt.htm
http://www.marxrv.com/12volt/12volta.htm
http://www.rv-dreams.com/rv-electrical.html
http://www.wholesalesolar.com/deep-cycle-battery-info.html
http://www.batteryfaq.org/
http://handybobsolar.wordpress.com/the-rv-battery-charging-puzzle-2/