Powering up the Motorhome

To live any kind of 'normal' life on the road we will need to have access to some sort of power. We also plan on frequent free camping since it is a lifestyle we really enjoy now that we have been introduced to it on our Western Australia trip. By the way, free camping is the Australian equivalent similar to boondocking or rather dry camping which is basically camping anywhere (legally) with limited or no amenities.



Since we plan on spending the majority of our time free camping we did a lot of research and thus have possibly made our motor home rather unique. We chose not to have any gas. (The wife has a 'thing' against gas since one self ignited in our first home. Thankfully we were home at the time and avoided damage to the house and ourselves!) Optioning for no gas, not only saved the costs of having it installed and certified by the appropriate authorities we also believe it to be safer.

Our power supply 240v also is not very conventional in a few ways. Most of our appliances will be regular household appliances even though we intend to spend weeks at a time free camping, we believe we have ensured that we will have enough power to run these appliances even if there should be some cloudy or rainy weather.

Our Induction cooker
Ordinary household fridge with a microwave oven on top
We opted for lots of  solar panels on the roof to ensure plenty of power. We covered all the spare spaces on the roof with small solar panels since this utilized the area available much better than larger ones plus they fitted the slope better too. Smaller panels also have better power generating capacity especially when some shade falls on a panel. See our blog post on solar panels for more details.

The bus roof full of solar panels
Adding more batteries to run everything only works if you have adequate generating capacity to charge them. We opted for solar panels and lithium batteries.

We installed solar panels on the roof to ensure plenty of power but then we had to ensure we could harness that power and after much research, we went with lithium batteries, for many reasons but mainly because they are much more efficient. The batteries are 400amps at 24v Lithium batteries and are controlled by a Dingo controller using SSR unit to take the bulk of the power from the solar to the batteries using a Vitron shunt off a negative cable to show us the amps, volts etc.

Connecting the Lithium batteries together

We have a separate 12 volt system and we have connected to solar 80w panel in the control box as well. 12 volt used to be the standard for extra low voltage power systems eg led lights etc. 

Dingo solar charge controller
Rob wanted 2 different systems. If we use 12 volt out of a 24 volt system then we are only using half of a battery which s not  good for constant use. A 24 volt system is more efficient because you can use smaller cables and higher output  to allow a more efficient distribution of power. So we are going 24V with a 240V inverter.  Sine wave inverters provide the same quality of power that you can expect from mains power. They are therefore safe to use with all your electronic appliances but they do cost more than the modified square wave models.

Battery Inverter

The higher the current (measured in Amps) the bigger the components need to be. High currents require large diameter cables and fuses, both of which can be expensive. However by doubling the voltage you get double the power (Watt) at the same current.


Generators


Sure we could have considered petrol generators, which are a cheaper alternative but they are not very neighbourhood friendly, they are noisy, they are not allowed in all campsites and you need to cart extra fuel for them as well as that creating on-going running costs.We have been at some camp sites that generators run upto 18 hours. Luck has it we were far enough away not to have to put up with these ourselves, though we feel sorry for anyone close by them.


I am hoping we never need a generator - only time will tell.

4 comments:

  1. A most interesting read Michelle. Well done and explained very clearly. Even I got it. I am sure many people would like reading this. Even if one had no plans to do what you have done, it is interesting knowing how automotive electricity behaves. Thank you.

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    1. I am glad it makes sense to you. It is still double dutch to me. I am absolutley hopeless when it comes to electronics and machinery. I had to 'interview' Rob and even then I had to get him to review what I wrote to make sure it was accurate even if I had no idea what I was talking about! ;)

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  2. Makes sense to me, and from my reading of other projects it takes some of the complexity out of things by keeping everything 24v instead of reducing it to 12v. Thanks for the info, look forward to seeing how it turns out.

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    1. I am so glad you were able to understand it. I am afraid I was way out of my depth here. I had to try and put Rob's words into layman's terms even when I didn't understand what I was writing!

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Thank you so much for popping by, I appreciate your comments!
Michelle