Solar

We need internet and power for laptops from 3pm to 9pm five days a week for the kids school.

I wired all our routers including the Mofi cellular router and our voip phone to the 12v battery through voltage converters however the kids laptop batteries don't last 6 hours.  We tried cheap inverters from Walmart which worked initially however as the batteries voltage went down the inverters couldn't keep up with the demand.

We thought the next cheapest option might be just to get a generator.  After much research we decided on a 2.5kw Westinghouse generator for $650 from Amazon as the Honda was only rated at 2kw and 2.5kw would run the air conditioning as well.  The reality was that the generator we purchased would not run consistently at more than about 1.7kw.  I don't know if it was because we saved $50 and bought a open box generator that was faulty or if it was because the inverter was set on UPS (un-interruptible power supply) which means it kicks in if voltage falls below 90 volts.  Anyway it kept kicking in and out and didn't work so I sent it back to Amazon and got a refund.   It was going to be a pain in the neck with noise and setting it up securely anyway so after this experience I was able to convince Sally that solar was the way to go, even though it was going to put a dent in her budget.

I bought:

A 24v, 2.4kw max 3.0kVA hybrid solar inverter charger (will automatically kick in instantly if power is disconnected)  This will enable us to use the microwave and coffee machine and will actually run the air conditioner although not for very long with our current batteries.  This unit will handle up to 2kw of solar panels so we have the option in future of adding more portable panels or putting panels on the trailer if we need them.

Another 100ah deep cycle battery.  Total 400 ah of batteries between the camper and the trailer plus another 100 ah or so in the truck which has two batteries.

A dual battery management relay / controller and 4 gauge cables, in line fuse and Anderson plugs for the truck to trailer and camper.

1 gauge cable, lugs etc to run from batteries to inverter, 10 gauge 110v cable to run to and from inverter to camper switchboard plus dc and ac circuit breakers.

12 to 24v and 24v to 12v high power converters to step up power from the truck to the now 24v camper and down from the now 24v batteries to 12v to run the camper lights.

Nine 100w monocrystalline glass fronted 22 volt solar panels.  Looked at flexible panels which would have been easier and can be walked on however water would have sat on them as we have a flat roof and they get water marked and dirty - they also can't be tilted if you stick them down.

Nine tilt frames.

Solar cable, mc4 connectors, dicor and screws.

The result - Fantastic!

The panels produce consistently up to 700w and up to 850w for a short time on a sunny day.  The panels seem to actually store some power when the batteries are full and on initially putting on the coffee maker or microwave the solar panels produce 850w for a minute or so before dropping down to a more consistent 650, 700w in full sun.

We just plug the trailer in to the camper when parked and the trailer then has full power just like at a camp site.

When no shore power is available the camper batteries are charged by solar or a trickle charge from the trailer batteries or truck when driving through the 12 to 24v converter.

The trailer batteries are charged from the truck alternator through the dual battery manager and heavy 4 gauge cable when driving or from the 110v mains converter when plugged in to the camper.

Despite over 400ah of deep cycle batteries I would still ideally like more storage.  We free camped for a couple of days in the one place recently in cloudy rainy weather and the dc fridge in the camper went off and did not restart.  If the voltage falls below 23v even for a short time the fridge will shut down to protect the battery and will not restart until voltage is at 25v or so.  Although we never ran out of 120v power through the inverter the voltage probably dropped below 23 when the microwave was used or something and then the fridge went into battery saver mode.  Due to the cloudy weather the battery never got back to full charge so the fridge did not re-start.  We really need Lithium batteries that can sustain a higher current draw without so much voltage drop however these will have to wait for more money to be available.

For comparison NorthStar charge $1110 for a two 80 watt panels and a 30 amp controller.  So I thing we have done ok.

Costs: ($US)

Solar
Main components
Tilt frames	$     323.28
Nine 100w HQST Monocrystalline compact panels	$     900.00
MPP Power Hybrid inverter charger	$     659.00
Total Main components	$ 1,882.28
Ancillary components
breaker box	$       13.99
32A ac breaker	$       11.52
150 A dc battery isolater/breaker	$       23.99
10 awg ac cable	$       67.98
62A dc solar breaker	$       15.99
alloy sheet	$         9.88
1 AWG cable	$       68.96
1 AWG cable lugs	$         6.34
24-12v 45A converter	$       26.99
12 to 27v 40A adjustable converter/ charger	$       33.89
10 AWG solar cable	$       73.98
Sikaflex	$       16.85
eternabond cleaner	$       16.10
MC4 crimping tool	$       15.59
MC4 connectors	$         9.99
MC4 connectors	$       20.97
MC4 3 string to 1 string connectors	$       20.97
screws	$       11.59
2 awg cable for battery series connection	$       23.68
Total Ancillary	$     489.25
Total Solar	$ 2,371.53
Dual battery system Truck Charging
4 gauge cable	$       28.99
4 gauge cable	$       44.70
4 gauge cable	$       28.98
4 gauge cable	$       24.98
150 amp in line fuse	$       12.99
350 amp Anderson plugs	$       16.99
dual battery manager	$       49.95
breaker	$         6.75
150 amp anderson plugs	$       18.60
100 AH deep cycle battery	$     115.00
Total dual battery system truck charging	$     347.93
Grand Total	$ 2,719.46