250w Module / Schneider Xantrac C40 Charge Controller / 12v Batter Bank

[SolarJoel]

Hey guys,

Anyone using the Schnieder Xantrac C40 charge controller? I'm trying to get some advice on fine tuning the potentiometers for stable charging.

My charges lately have been super erratic. I added a "diversion load" so there was always something running at 12v and that's helped a lot.

I'm trying to figure out what the safe peak charge for a 12v bank of deep cycle maring batteries would be. 13.10v? Higher? Lower?

IMG_3852.JPG

Any advice? I'm wanting to add 2 more batteries to it soon and use this for year round free heat and cooling in my detached garage.

-Joel

[inetdog]

My first advice is that by using this "free" heating and cooling, you will end up paying more for battery replacement than you would pay for power from your utility.
Other than that, if your charging is erratic, there is most likely a problem with your CC, batteries or wiring.
To give more specific advice we will need more details about just what "erratic" consists of.
Also, some Xantrex units have serious firmware bugs that affect absorb time and other charging characteristics, so your problem may be beyond what you can correct with the voltage setting pots.

[SolarJoel]

^ That's discouraging.

I'll have to get you more info. I'll put up a diagram of what I'm running and maybe it'll help. let me just get a few things together.

[Sunking]

Bulk = 14.4
Float = 13.4

[SunEagle]

^ That's discouraging.

I'll have to get you more info. I'll put up a diagram of what I'm running and maybe it'll help. let me just get a few things together.

Besides the wiring diagram please provide a full list of hardware including panel specs, battery Ah, inverter and charger. Sometimes one of those components are mismatched and will ruin your battery.

[SolarJoel]

Bulk = 14.4
Float = 13.4

That's right about where I've ended up setting it. Maybe a little lower on the float.

Would you care to explain why you like those numbers for the general education of anyone else reading?