Tech Talk with Driver Dunc – The New Inverter

Ok team, Dunc here as it's time for another technical rant from me. If you don't want to be bored by the techno stuff then skip this entry and read the next one :-)

The inverter on Bertha runs from the house batteries and provides the 240 volt power to run the fridge and the freezer and all other electrical appliances. It has been running almost continually for the 5 months we've been away, but there have been ongoing issues with it.

I had been in touch with the manufacturer of the unit in Taiwan to see if there was some way of adding a standby mode to it. Having the unit on all the time generating power continuously results in very short battery times. I also asked if there was an Australian agent as I wanted to get it checked over as it was reading the batteries low - 22 volts instead of 24 volts. Apparently there is an update to the unit, which involves unplugging a few boards and plugging new ones in in place of the old ones. Not very expensive either. When I asked how I could get this upgrade, I was told the engineers would not let me do it myself, and they wanted me to buy a whole new unit!

I left it at that as I had a feeling this unit would not last the trip. There had been some unusual overload issues with it and it seemed to be struggling to just start the fridge. I started looking around at other rigs and seeing what they had but their units were all quite expensive. So I started looking at cheaper units on the ever reliable eBay but to no avail and really I was reluctant to spend more money after buying a new engine for the girl in Feb unless I really had to.

We had met a lovely family in Adelaide driving a bus and an old motor home around the country and caught up with them in Karrinyup where I described my issues. Pete has an electronics and solar background and agreed that the current inverter was in fact a strange beast (nicer than my calling it a P.O.S.) and that he had bought a unit off eBay about 18 months ago for his bus (being used by Beyond Blue at the moment) and that he had just ordered another one for their motor home and was more than happy with it.

I checked it out, the price was reasonable, he was knowledgeable and had bought 2 units as he was so happy with it, so I decided to order one myself. The new unit can provide 6000 watts at around 95% efficiency and will peak at 18 Kilowatts which is more than I would ever dream of putting through this cabling. It would take one week to arrive.

We left Karrinyup (pronounced Karinup ... Don't get me started on Cockburn ... which is pronounced Coeburn but that could be a whole other post from me :-/) and went to Gin Gin where, after a masterful bit of parking, I hooked up to the power there. Oddly just before I hooked up we had an overload on the old inverter, which worried me as they were becoming more prevalent. All was good until I unplugged the power to leave the next day and it dropped straight into overload and would not restart at all. The old unit had died ... 2 days too early!!!

We made our way to Freo and set up there with an extension lead through the driver’s window to get the fridge back up and running. I proceeded to jerry-rig the power to work without the inverter and get all of Bertha's electrics back up and running.

Now, as our luck would have it, the day I ordered the new inverter there was a derailment at Coolgardie which was affecting all freight across the country, so there was a bit of a hold up on the inverter. I had a rather terse conversation with an operator who advised that the unit might arrive next week sometime. I was not impressed and gave this robot a serve about what this is costing and she dutifully took notes and handed me to another team who promised the freight would magically be in Perth the next day and that it would be delivered the day after. The short story is that I wasn't super happy with that either and I ended up at the other side of the airport at the TOLL terminal picking up the unit to speed things up and avoid paying for another night at Freo Village CP. The upshot of the drive was that I got to drop Jerry to the airport and score a beer in the Virgin Lounge ... Just like old times :-)

After some redesigning of the fittings and mounts and a couple of trips to Bunnings, I was able to muscle the 35 kg beast into place. Actually the old one is heavier than that and was even harder to remove without breaking me or anything else important.

Anyhoo, the new unit is happily ticking away and is going into standby to conserve the batteries as it is supposed to. With this new inverter, we should last 3 to 5 days free camping before we have to go and give the batteries a good charge up in a caravan park. This is a vast improvement on the old unit, which would really only last one night before complaints about low battery.

The strangest thing about the new standby function is that the light in the fridge won't come on in standby mode ... Maybe I can rig a 12 volt light in there ... Ah but that would mean another post to bore you with and I couldn't do that ... Or could I?? ;-)

Suffice to say I am a more relaxed camper now! :-D