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A trip to Barrington Tops

January 2021 – the weather was warm, so how about a few days camping in Barrington Tops?

A misty morning at Polblue campground

The afternoon before we left, we filled the fridge with goodies and disconnected the mains. You can see the voltage dropping suddenly when power to the charger was cut, then it drifted lower overnight, dipping every time the fridge came on.

Early next morning we headed away from Sydney, our car charging the batteries nicely as we drove.

After stopping for morning tea (no battery charging while the engine is off, so the voltage fell back for a while…), we drove for a few more hours, arriving with the batteries fully charged.

We arrived from the western end. We’d been a bit concerned about the “no caravans” signs, but we navigated the twisty turns with our trusty camper trailer in tow – no problem at all, and well worth the amazing views!

Just had to get through the gate before driving on to the Polblue campground…

Nicely situated with a view of the swamp

The batteries were already pretty well charged from the drive, but we setup our solar panels anyway – ready for the next morning.

The trees gave a lot of shade, so not much charging happened – as you can see from the very minor rise in voltage in the afternoon.

I’d thought it might get colder (that was yet to come!) when camping 1500m up, but the night wasn’t too bad: dropping to 10.5°C just before dawn.

Mind you, that was measured in the battery compartment – it would have been a touch lower outside!

Quite a sunrise through the mist

It was a reasonably sunny day.

The dappled shade of the trees around our campsite didn’t make for great battery charging, but we nevertheless got in some good charging during the morning, before it clouded over – enough to keep the batteries topped up.

The next day was cold.

How cold? It maxed out at 12.3°C… and this was the middle of summer!

You can clearly see the three days thus far in the temperature graph. Plenty warm during our drive through the lowlands, then warm enough for our first full day up the mountain – and then the mist and damp came in the day, and it just never really warmed up that day…

Ever hopeful, we angled the solar panels toward where the sun seemed to be, trying to catch a ray or two…

And, amazingly, despite the gloom – there was enough sunlight to get in a bit of useful charging in the morning, before the weather really closed in.

Ok, it wasn’t much, but it was enough to keep the batteries topped up!

Our final morning was much sunnier – it was a pity to have to head home!

The morning of our last day at Barrington Tops was nice and sunny, and our batteries were able to get in one last solar charge before we packed up and headed for home – charging (as usual!) along the way.

All in all a great short trip – even if freezing cold at times!

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Why a Battery Recorder?

Toward the end of 2019 we found ourselves camping on the South Coast of New South Wales. That’s not unusual for us – we regularly set out in our camper trailer, setup to live comfortably off-grid with 2 x 100Ah batteries and a hefty 240W of solar panels.

At least, it’s usually comfortable. Over that summer, much of the South Coast was engulfed in fire. We were ok, but for days the sky was full of smoke and although we could see the sun, it was a feeble, strangely coloured thing.

Now, like a lot of campers with a 12 volt solar setup, I like to regularly check the battery voltage, to keep an eye on how much charge we have left. I wonder if the solar panels are doing their job, and whether we have enough charge left to keep the fridge running until there’s enough sunshine to charge again.

And on this trip, I was getting worried. Our solar panels were out, pointed toward the sun, but the battery voltage just didn’t seem to be going up! In fact, for a few days it was slowly and steadily getting lower. So I’d continually go and check it, a bit nervous about how it was going. For me, there’s a ritual involved – get up, walk around to the other side of the camper trailer, open the door to the battery compartment, read the voltage, close it, and walk back.

I thought – wouldn’t it be convenient to be able to check the voltage from inside the camper trailer, or from out the front or when sitting around nearby, beer in hand, without having to get up and walk around?

More to the point, I wondered if our solar panels were even working, or was it simply that the smoke was blocking the sun? More likely the latter, but how would I know? Were the solar panels making any difference, at least slowing the voltage decline? Maybe they charged a little in between the times I checked, and maybe sometimes I was checking the voltage right at the point when the fridge is drawing power, temporarily pulling the voltage down. Who knew?

I realized that to know how well our solar panel and battery setup was coping I needed to know, not just what the battery voltage was right now, but what it had been over the past few hours or days. I needed to see the trend. If the voltage was falling faster overnight than during the day, well at least that would show that the solar panels were doing something. But I needed that historical data – a record of the battery voltage over time. And I needed to be able to see it, quickly and easily. And wouldn’t it be nice to be able to see the current readings, as well the latest graphs of battery voltage, from anywhere near the camper trailer, and not have to go for that regular walk to check on it?

Now, at the time I was working as an electronics design engineer at company that makes data loggers for industry. I knew how to design a quality product that would be genuinely useful for keeping track of battery voltages, from the convenience of a mobile phone. And I could include other desirable features such as a temperature sensor (when out camping, I’d often wake up in the morning and wonder whether it was really as cold as it felt last night…) and an input for a second battery, because plenty of people have two batteries to keep track of.

I didn’t find anything in the market that met my requirements, and since I’m a electronics engineer and my partner is a software developer, why not develop a battery monitor and recorder that will be useful for us, and the many people like us with a 12 volt solar battery installation, especially our fellow campers?

The result is the Bushgeek Battery Recorder. We hope you’ll like it!