Solar BACK UP kit not full time OFFGRID ? help please?

[Nix]

Had a look on ebay for a system that should suit a lowish budget of £125 ish or less. All items are new and delivered to your door. Please note that I can't actually vouch for any of these cos I haven't bought them myself. DON'T buy from outside the UK, there's a good chance you'll be paying extra taxes plus, any problems will be a nightmare to sort!

Four essential items are:

- Solar Panel - 40W
- 10A Controller
- Deep Cycle Battery
- Inverter (optional)

Solar Panel:
Found a 40W polycrystalline panel here for £41.99 delivered. These guys also seem to hold auctions so there's an excellent chance of paying less, have a look in their ebay shop. This panel also comes with MC4 connectors which are waterproof connectors. Depending on the length of cabling needed, you can either buy an extension cable with MC4 connectors on or cut what you have and connect straight to the controller.


10A Controller:
I picked this one cos it will control 12v and 24v systems automatically so is flexible for future voltage upgrades. It also incorporates PWM technology thereby giving more efficient charging plus longer battery life here for £9.99 delivered.


Deep Cycle Battery:
Gotta be a little careful here cos quite a few sellers trying to sell auto batteries as leisure batteries. This little one here seemed excellent value for money at £59.95 delivered. It's an 88ah deep cycle battery with a 4 year warranty. Not bad.


Inverter:
All cheap inverters are modified sine wave ie the wave is a bit harsh and NOT suitable for things like power tool chargers. They seem to be ok for phone chargers (I tested one out on an old mobile), LED lights, computers, etc. The one I picked is 150W max and has two usb charger ports here for £13.99.


12v Power Adaptor:
For those who don't want the inverter but still want to charge small devices, this comes in at £3.49 and has a usb port plus three 12v power points to play with.


Those are the basics on a low budget. I recommend you actually get the highest Wattage solar panel you can plus as much of a battery back up as you can afford. General rule of thumb is that you get what you pay for but there are bargains if you are willing to hunt them down. The items above seemed a fair bet and represented great value from what I could see. Connections are fairly straight forward, connecting +ve/-ve solar panel output to +ve/-ve controller input. Then +ve/-ve controller battery output to the battery itself. Then it's simply connecting the battery via a suitable inline fuse to the inverter/12v power adaptor. For this set up, I'd probably use a 10 amp inline spade fuse. Cables no smaller than 1mm but 1.5mm would be better.

BTW, I use quick release battery clamps that I get from Amazon here for £7.24 delivered.


Also, I highly recommend you to buy a little LCD voltmeter to keep an eye on things here for £6.20 delivered:


There's a lot more info here in my original posting about solar back up systems here, might give you a better idea of the workings.

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Forgot to mention that the 10a controller would allow you to add another 40w panel in parallel if you so wish as a single panel is only 3.5 amps max output. You could also always add, in parallel as well, more batteries to make a proper battery array. More energy stored, more energy to use later!