Home made solar inverter generator hybrid

[oil pan 4]

This is my little off grid stand alone set up.

The current configuration is based around my 7kw rated 10,500w surge, 2 pole, 3600rpm gasoline powered single cylindet 420cc 13hp troybuilt generator with 8 gallon fuel tank.
This generator was a warrantee turn in at lows, I picked it up for $100. It had bad brushes, broken wheels and a dead battery. $14 got me a new set of brushes plus a spare to get it producing power again.

I knew this generator and ones like it suffer from catastrophic fuel consumption (the particular one uses .77gal/hr at half load and around .5 to .66 gallons per hour at light to no load).
That is perfect for me because I needed a fairly strong generator to run welding equipment and I wanted to to build a cart to put it on, give it more fuel capacity, put a huge battery and pure sine wave inverter to save on gas and run time.

The current configuration is this generator, with an additional 5.5 gallon fuel tank, spot to hold an additional 5 gallon red gas can, on a cart I originally built for a welding machine, an optima battery to replace the dead riding lawn mower battery and power the 1,000 watt Kisae pure sine inverter.
I rewired the generator to use actual real QO series breakers made by square D. Then installed L14-20, L14-30 and 10-50 receptacles.
With all cords, full fuel and everything else I added it weighs about 350 pounds.

I have found that I really like using the inverter to power stuff as opposed to running the generator. But due to the batteries limited size I have only ran tiny devices off it like drills, small saws, power tool battery charger, briefly run my 1hp air compressor of it to fill a tire or shoot a wire finish nailer a few times.
Its a great inverter, on a tiny battery. The optima battery was free.
I have had the battery and inverter on there since summer of 2013, now I am adding solar panels, charge controller and might upgrade to a larger battery.

The main problem with the battery is the generators built in magneto charger is only designed to replenish the power used by a tiny riding lawn mower battery used only for starting the engine, so it has to be charged up with a external battery charger to get a proper charge.

The new configuration will have:
A Morningstar prostar 30 amp solar charge controller.
At least two 80 watt solar panels (4 to 4.5 amps per panel).
My home made 240 volt powered odd voltage battery charger (supplies 16 to 19 working volts like a "12 volt solar panel"), this hooks into the Morningstar to supply up to 20 amps in place of or in addition to the solar panels.

The working configuration as of feb 2016 has a Morningstar 30 amp PWM charger and Morningstar 15 amp MPPT, the home made 240v batt charger, 1000w kisae inverter.
The Morningstar 15 MPPT handles the solar, the 30 amp PWM is a backup and handles charging from the battery charger.
The 240v powered battery charger produces up to 27 amps.
The Morningstar 30 amp PWM and 15 amp MPPT work great together.

I would like to add solar trickle power into the battery and be able to run more small items or intermittently run larger items like my air compressor or a refrigerator with out immediately killing the battery.
Then put the bigger battery charger on there to more quickly charge the battery with the generator and go back into battery+inverter only mode.

I would like the to new configuration to stay under 500lb after I add a bigger battery.

Future up grades will include:
A much larger deep cycle battery (when this battery quits).
An electric fuel pump to make swapping out the fuel after it sits all winter easy and to turn this into a gasoline dispenser for power equipment so even if it doesn't get ran I will still have fresh fuel in it.
A hot water heating system using exhaust heat

This is when I was working out building the battery holder and where to put it:


Rewiring the generator to use the types of receptacles I like.


Here is the genset with the battery and inverter installed and just after installed the additional fuel tank (free from the scrap yard).
The solar panel need to stow on the side so I can use those lifting rings.


Unused room to stow solar panels. Solar panels will need to be removed before starting the engine.


I don't have any 5-15 or 5-20 receptacles on the generator its self as of now, but do have this L14-30 power distribution cord I made and another L14-20 power distribution center that came with the generator (not shown).


This is the 240 volt battery charger I am working on. When I apply 240vac to the 380v input terminals of the transformer gives 16.3VAC, which after rectification gives a max theoretical open current voltage of 23vdc.
The capacitor was pulled from a broken battery charger. The heak sinks and rectifiers are left overs from my AC to DC welding machine conversion.
Heat sinks came from the scrap yard, paid maybe $1 for both.


The water proof DTSP input power switch. 16ga SJ cord is sealed with a gland seal type strain relief at the switch. You wouldn't believe how hard it is to find a water proof, 240 volt powered battery charger....


I would like to mount a solar panels to keep the sun off the fuel tanks and inverter. I have rubber shock absorbers to put between the panel and the rest of the structure. Will that be enough?
Or can solar panels not withstand any vibration?

I could not find a solar charge controller that had a generator power input for backup battery charging. Does any one know of one?
It looks like I will just build my own, but any suggestions are still welcome.

EDIT: Morningstar does not recommend running a battery charger through their PWM charge controller.

Basic lay out of how the components interact.

[jeff5may]

Wow! What a summer project. Better keep the tourists away from it: someone will give themself a heart attack!

[oil pan 4]

The buss glass tube fuse holders I ordered came in, $14 for 4 double 30x5mm glass or ceramic tube fuse holders. I put a 3 amp fuse on each line.
I did a functional check on the battery charger components as a whole system.
With input voltage of 245 volt AC made an output of 21.5 volts DC.
Which is perfect solar panel replacement voltage.

Next put a 20 amp fuse on the output, secure everything inside the case, attach to the generator and hook it up to the Morningstar, with battery and see if anything gets fried.

[oil pan 4]

Picture time.
This is kind of what the lay out will consist of.



The heat sink I am using for this is one just like I pictured but with about 1/3 cut off it and painted flat black.

On my big AC to DC welding machine conversion I run these same bridge rectifiers at up to 100 volts and at 25 amps each for 90 seconds at a time when I burn an 18 inch long 3/16'' 7024 electrode. They are on a slightly larger heat sink with a fan.
This application will put one bridge rectifier on a big heat sink, with no fan and only up to 20 amps going through it continuously.

[oil pan 4]

Getting the box put together.

The transformer is bolted through the box, through the generators frame in 2 places.


The rectifier looks like its sunk down into the box, but its actually sitting on top of a heat sink that extends off the edge of the frame but has a caster support under it.


Now with the battery charging capacitor installed. All wire is 12 gauge, if I have to I will up grade to 10 gauge, I have plenty of TH or TW 10 gauge on spools.
My automotive fuse holder says it is "30 amp" but its only on 12ga wire. I had a heavy duty "40 amp" automotive fuse holder but I used it and can not remember where I bought that big 10 gauge wired fuse holder.


Then I moved where the input power comes into the enclosure. It did go in at the switch.
I also installed a 4 hole gland seal for 10 gauge wires incase I want to add more or bigger wires later and its the closest gland seal I had to fit the bill.


FedEx is just taking their time getting my Morningstar controller to me. They have had it since august 31 and it has only made it to dallas.
I bought two 80 watt solar panels, FedEx has them too, they can take their time getting them to me I don't want them to get smashed.

[oil pan 4]

The Morningstar came in, installed it, wired up the battery inputs and tested the output terminals by wiring in an old headlight.
I did not get to wire up the "solar" power inputs.

[oil pan 4]

It works so far.
I hook my Kisae inverter up to my refrigerator, which I already know works turned it on and power started dropping, as usual.
I had already hooked my 240vac charger up to the Morningstar controller. After powering the fridge for a little while battery volts dropped to 12 even.
Figured this would be a great time to test my battery charger. It was already hooked up to grid external power all I had to do was flip the switch.
About 3 seconds later I herd a click that sounded like a fuse blowing. My 20 amp blade fuse blew. So I turned off the battery charger and plugged in a 25 amp fuse.

The 25 amp fuse did not blow. So I put my fluke325 on there and it was reading 26 amps going to the battery and inverter. The inverter was only drawing 11 amps at 14 volts.

So now I will upgrade to 10 gauge wire on my battery charger. And put on a 10 gauge 40 amp NAPA in line blade fuse holder. I will fuse the circuit at 30 amps to reduce nuance fusing.

I may also install a charge limiting resistor like I have seen used on NiCd batteries.
This battery charger need to be able to charge low batteries with out fusing.

[oil pan 4]

Here are some thermographs I took while torcher testing my charger, charging batteries and running the inverter to power my refrigerator.
The bridge rectifier gets too hot for my liking.
It was showing 250'F while at or near 25 amps and at 11 amps it would only cool down to 214'F.




I am going to install double heat sinked rectifiers to keep them from burning up. Then install 24 volt fan to circulate air through the enclosure.
The 25 amp fuse was showing 330'F at 26 amp full load. It only cooled down to 225'F with 11 amps going through it.
I am going to get that gigantic NAPA fuse holder and 30 amp fuse, I hope they still sell them.

I think this flir is saving me from a lot of future arse pain.

The idea behind the battery charger isn't to power loads and charge the battery at the same time but I still want it to be up to the task.
I may use the generator to power my plasma cutter which takes every bit of power it has, so I may leave the battery charger plugged in which only uses up to about 2 amps of 240 vac power to at least charge the battery while the generator is running, I may also have to power some important load like a refrigerator that is starting to get too warm. The refrigerator would not like being plugged directly into the generator while the plasma cutter or welder is going.

At that point the generator, battery charger, solar, Morningstar and inverter will form some kind of primitive uninterruptable power supply.

[Daox]

Sounds like you're doing a quality build. I'm looking forward to more.

[oil pan 4]

This is what it looks like.
I also added a 50 amp Anderson connector to the load side of the breaker, this makes attaching a small 110 volt charger/maintainer easy. I lopped that Anderson connector and a lot more just like it off a pile of bad UPS at the scrap yard. They cost almost nothing in that state.


I was going to use inline fuse holders and terminal boards to make connections. But then I found this at advanced auto.


Looks like I am going to upgrade the wires coming out of the charger to 10 gauge, can the inline fuse holder idea all together and use that busman. Then from the fuse block to the Morningstar and from the Morningstar to the battery install 8 gauge wire.
Because the Morningstar can be overloaded by 25%, which would put it at 37 amps.

The busman will also make it easier to connect and disconnect solar panels.

Also I believe I need to replace a battery in one of the vehicles, which just happens to be able to take a group 78, which is the size of my optima.
I was thinking about replacing the optima with a larger and heavier Diehard group 34M AGM battery.

I went with the sears AGM because I found out that they are made by odyssey.
Also I was looking up specs on the group 34M, its as wide as my optima and about 1 inch longer and it should fit into my battery holder.