AC Coupled Battery Charger

Hi All,
I am building up my own little microgrid slowly and I was thinking I would do AC coupling rather than DC. I am looking around and I see that wind turbines would work better in one spot, solar about 500 feet away and then the build site for the house is elsewhere...

Does anyone have a lead on a good battery charger that is not an inverter charger?

I am very tempted to just full wave rectify, filter, and feed my line voltage into a solar mppt charge controller... Are there any huge risks with this I am missing?

I have not been very impressed with inverter chargers and as I have had some recent failures of inverters I want to keep things separate.

Thanks for the feedback

P.S. not looking for feedback on how to manage syncing all the sources dropping power on the line and be told I'll blow my inverter if I don't thanks...

Here is a AC to DC 1000W device.
https://www.wholesalesolar.com/2915346/cotek/battery-chargers/cotek-cx-2440-battery-charger

Solar
If you are willing to cut down some trees that is blocking the sunlight you should be able to get some solar closer, either on top of the house or some type of barn/workshop/garage/poolhouse building.

Wind Turbine
Most wind turbine only give you their rated power at 30miles per hour and at 10mph you will get 1/20th the rated power aka
1000W = @ 30mph but 50W @ 10mph.
So unless you have a 200ft pole in addition to regular/ground wind speed of 15mph you will not get much electricity.

Now they do have battery charger/controller that will accept power from both solar and a wind turbine so you can have the flexibility to do either or both.
http://mwands.com/store/a400-digital-volt-and-amp-wind-and-solar-charge-controller

Interesting thread. By AC coupling do you mean multiple grid tie inverters (not tied to THE grid but just to each other) to make your own AC grid?

Is this to avoid the losses from low voltage DC transmission lines?

Joe Wamsley wrote:Hi All,
I am building up my own little microgrid slowly and I was thinking I would do AC coupling rather than DC. I am looking around and I see that wind turbines would work better in one spot, solar about 500 feet away and then the build site for the house is elsewhere...

Does anyone have a lead on a good battery charger that is not an inverter charger?

I am very tempted to just full wave rectify, filter, and feed my line voltage into a solar mppt charge controller... Are there any huge risks with this I am missing?

I have not been very impressed with inverter chargers and as I have had some recent failures of inverters I want to keep things separate.

Thanks for the feedback

P.S. not looking for feedback on how to manage syncing all the sources dropping power on the line and be told I'll blow my inverter if I don't thanks...

Could you use a high voltage charge controller instead? Also, if the array is not very large and operated at reasonable voltage, the wire size will not need to be large.

Problem is that most smart chargers that have enough gusto for a house battery charger are nearly as expensive (usually less when all told) as a good inverter charger.

If ac coupling is in the design for other reasons than distance to sources, a hybrid inverter such as outbacks fxr and some others, are a good investment. Monitoring, co-ordination and transfer switching, integration , reliability, efficiency and overall performance and safety are off the shelf easy with a magnum, sma or outback.

Hi Joe,
As usual Frank covered most of it but could you quantify the amount of generation we are talking about? I see two reasons you want to ac couple
1 multiple locations you want ac at or concerns over line loss with the dc.  We recently used morningstar's 600 volt mppt charger and it's working well one year in. That location array was over 300 ft to the battery bank with less than half the line loss ac would have had. Next would be the wind turbine. Usually the small ones are 3 phase ac rectified at the batteries either on an mppt controller with a clipper or just a straight voltage regulation type. The ac grid tied turbines are... tricky more so as you get smaller.
I have found the name brand inverter chargers more problem free then the comparable ac gear and more flexible towards input sources. For chargers if 1kw is your target I like the iota chargers myself.
Cheers,  David