Wind Rectifier Not Charging Battery

Presumably, the 3 green wires are connected to the three wires of the turbine, and the Red wire to battery positive, and the black wire to the battery negative post.

To check the function of the turbine (when it is pretty windy)--Set your meter to AC voltage and see what the green to green voltages are (there are three combinations you can measure--1-2, 2-3, and 1-3. All the voltages should be >~ battery voltage if the turbine is running. If one or more of the voltages do not match, then you may have a bad turbine (winding fail, slip ring fail, etc.).

On the battery side.. Setting meter to DC voltage, for a 12 volt battery bank, you want to see >13.6 volts to actually get the battery charging... And ideally want to see 14.0 to 14.8 volts when fully charging (depending on battery type--car battery, flooded cell, AGM, GEL, etc.).

If you want to experiment more--You can get an LCD panel current/voltage meter from Amazon to place in the battery wiring.

Or for more experimentation, you can purchase an AC+DC Current Clamp DMM (digital multi-meter)--Very handy for debugging:

https://www.amazon.com/UNI-T-Digital-Handheld-Resistance-Capacitance/dp/B0188WD1NE (inexpensive, good enough for most of needs)
https://www.amazon.com/Auto-Ranging-Resistance-Klein-Tools-CL800/dp/B019CY4FB4 (mid-priced DMM Clamp meter).

Note there are AC only current clamp meters--They are also very nice, but will not work (current clamp measurements) for DC current.

Just a comment... I am NOT a fan of small wind systems. Ideally, you need to mount the turbine on a tower at least 30 feet tall and an area free of trees/tall building/etc. to ensure a steady airflow. Wind turbines do not work well (if at all) in turbulent air flow.

Mounting a turbine to a building/home (pipe/post bolted to roof/wall of building) will be noisy and potentially the vibration could damage the building.

Wind turbines normally need servicing every year (grease bearings, clean and inspect slip rings, check bolts are tight)--Which can be a pain if the turbine is not easy to access.

Also, not great to place turbine near homes and yards where people are... More than a few turbines have shed ice, blades, or nacelles have fallen in high winds.

And many (most/almost all?) small wind turbines fail to harvest a "useful" amount of energy. Whether poor design, or turbines in "poor wind" locations/conditions, or they simply fail in a year or two--They just are not worth spending the time and money on (a 30 foot tower is neither cheap or easy to install).

Depending on the "rectifier" design... HAWT (Horizontal Axis Wind Turbine) need a constant load to avoid over-speeding. This generally means connected full time to a battery bank with a "dump load" controller (to prevent battery from over charging) or a turbine controller that will shut the turbine down (typically by shorting the AC output wiring) in high winds/when battery is full.

Most HAWT units that are unloaded (failed alternator, failed slip rings, bad rectifier, etc.) can spin "scary fast" and even self destruct in high winds--Again, do not mount turbines near people. The turbines need loading (typically battery bank+dump controller) to keep them from over-speed in high winds.

For example (obviously, not a small home turbine):
https://www.youtube.com/watch?v=MGuiDs3ush0

-Bill

Happy we can help Jim...

Note: Lead Acid batteries are a "bit complex" when trying to estimate the state of charge. Resting voltage (3 hours or more of non-charge/discharge) is one quick and dirty method. If you are charging or discharging, voltage vs SoC will change depending on...

https://www.scubaengineer.com/documents/lead_acid_battery_charging_graphs.pdf

More or less, Lead Acid batteries being stored (vs active cyclinot ng) should be kept above ~75% SoC--Or they will tend to sulfate (faster)...

11.99 volts resting is around 20% or less SoC--You need to get the battery charged soon (as in hours/day) to above 75% SoC...

For flooded cell lead acid with cell caps (not sealed), using a good Hydrometer can give you better SoC estimates (specific gravity needs to be temperature compensated too).

Hydrometer:

https://www.solar-electric.com/midnite-solar-battery-hydrometer.html

Glass float hydrometers are good too... Just make sure that they don't roll off the bench and break (happens quite often). Also, rinse with distilled water after use (the drying electrolyte can get "sticky" and make floats inaccurate).

At this point, getting your battery(ies) on an AC charger is pretty important... I would not count on a (any) wind turbine to bring them up  quickly enough. Ideally, you would want a minimum rate of charge of 5-10% (i.e., 100 AH Lead Acid battery, 5-10 Amp minimum cert of charge).

It is certainly easy to over charge/damage a lead acid battery with an AC charger--But most batteries are killed by under charging/over discharging.

Longer term project, I would suggest solar panels and charge controller... Solar in sunny area (no trees, shade, etc.) are usually able to "reliably" produce predictable harvest. Use wind for deep winter/stormy weather.

-Bill