help newbie with charging house/solar battery

I have a 2014 ford E250 4x4 van conversion. I am just finishing the interior conversion to a camper van with a pumped water source, No built in stove and no htr.

has 3 100w renolgy eclipse panels on the roof.

A 255ah lifeline battery for the "house" linked up with the starter battery thru a "Blue sea ML-ACR automatic charging relay, fused at both batteries with a blue sea marine grade disconnect just before the "house batt".

A renolgy 40 amp commander controller, panels have a disconnect before the controller.

A renolgy mt50 digital charge controller(hooked to the 40amp commander controller) to monitor the house battery.

An Xantrex "link lite" digital gauge that is set up to ONLY monitor both batteries, kind of a redundant monitoring system.

Blue sea systems fuse box with disconnect between batt and fuse block, currently all systems off EXCEPT the MT50 and xantrex are wired with fuses but wired to be on all the time. (KNOWN parasitic drain)

Van is stored in my garage all winter,cold in Montana right now, so far garage has not gone below 40deg.
I do have a forced air furnace on the ceiling in the garage.

Yes I have shore power in the garage, I tried hooking up one of my "Yuasa mili amp" charger to the house battery(cause I have 5 running in my garage all winter long for other battereis) but doesnt seem to do alot with this 255ah batt..

So just started trying my old 4amp charger last night.

So, questions..
I assume its ok to leave a large battery charger on the house battery all season long? correct?

what does a Large amp battery charger mean? How many amp charger should I get?

What brand charger, model, any help very much appreciated

thanks

Yes, please post exactly what RV you have.

Also, do your have shore power where you store it?

Stored outdoors, under cover or inside?

Without answers to those questions, you could get a lot of correct answers that do NOT apply to your rig/situation.

Battery monitors are available that can show voltage, amps, battery charge %, etc. But they may not be necessary or practical for your situation.

What do you have? A truck only with a house battery and no camper. Or a MH with a Ford chassis? It wasn't clear to me how the solar panels were connected to just a truck.

40F is helpful and a small charger should be OK but leave it on for days if not all winter. I leave one on a car for the summer while we're traveling.

Oops Lifeline - My posted number of 14.8V should be about 14.4V. Check the Lifeline specs for your model as the AGM charging requirements are different than flooded batteries.

For charging a discharged battery the charger size is dependent upon how much time you have. I have 80A for 440A Lifelines and they can accept much higher. Rarely do I see 80A. A 15-20A charger with a AGM setting would be good. But a smaller charger for maintenance is good.

The MT50 is likely OK for solar, but generally the lights aren't very helpful. Maybe someone with experience on that controller will post.

Im a newbie at this, so just looking for some guidance to get me on the right track.
Im thinking you mean the alternator as"the charger that came with the rig", just havnt had time this winter to get out for a long drive, to much snow and cold for the time being.


My Lifeline battery is an agm.
I did go to lifelines site and check the charging voltage requirement for a 40deg garage.

I had no idea the 4amp charger is too small!

What size charger should I get?
Any specific type of charger?

Is the MT50 basically an idiot light, worthless?
Sounds like maybe your saying I shouldnt pay attention to the MT50 and just check the battery with my multi meter?

blueh20 wrote:
hi, trying to learn about keeping my house/solar battery in good condition. My parts.
-3 renolgy 100w eclipse panels,
-renolgy 40amp commander controller,
lifeline 255ah batt ,
renolgy MT50 digital controller.

My first winter with my solar system(ford e250)sitting a little stagnant in my garage.
I do drive it just enough in the winter to keep the battery up but lately its gotten down to 12.5v so I stuck my 4 amp battery charger on it.
In about an hour the MT50 registered 14.1v but the Battery icon on the MT50 showed the battery about 2/3 full and seemed to just stop increasing.
After 2 hours the MT50 still registered 14.1, the battery icon was still at 2/3+ full.(battery charger had floated down to 2.25amps)
Not trusting that I know what I am doing,so before bed I just unplugged the charger and figured I would start over in the morning.
This morning the battery was down to 12.5v again, stuck the charger on and its on its way back up to were it was last night.

seems as though I just need to leave the charger on for a longer time,

My question..is this scenario normal?
What should I do, thanks.

I'm not a solar expert but I have Battery Minders on all my "stuff" in the garage - riding mower, tractor, diesel truck, etc. The Battery Minder will condition all my wet-cell batteries and will not overcharge, even when left on for extended periods of time. Under those circumstances I don't worry about voltage, I just make sure the water levels are good. Hope that helps.

Idiot lights as they are known have one redeeming feature. They allow the salesman to explain what a great battery monitor you have!

Why are you using a small charger for the house battery vs the house charger that came with the rig?

Discharged flooded batteries should bulk charge at 14.8V. A 4A charger is inadequate but left on for days may charge the battery. If the battery is NOT completely 100% disconnected then house drains may account for the 12.5V.

From your post the battery is not being fully recharged and it may have less capacity due to being under charged for the winter so far.

BTW 14.8V is for 70F and the temperature corrected voltage is higher for a Montana winter. Even up to 15.9V, something to consider.