Friday, July 5, 2019

Campout Wrapup

We got decent solar while driving up to Eklutna Lake but there is lots of shading here at the group campground. We’ll see how we do tomorrow with the morning sun. Instant Pot pasta and microwave veggies. So, a heavy-ish load on our batteries. After dinner, it was 91%. We’ll see what it is tomorrow morning. Given the shading, I may need to run the generator in a couple of days. 

07/03 - This morning, the Trimetric monitor read 75%. This is with the cpap machine running all night and two cups of coffee in the morning. 

07/04 - Today, I ran the battery bank down to 69% before running the generator. And it has been charging at about 50-65 amps the whole time. I’ll stop at around 90% state of charge (SOC) as the charge rate drops to about 30 amps at that point. 

For the pot-luck this evening, I made “Killer Potato Salad” from Flo Lum’s Instant Pot cookbook. Very tasty (assuming you like shrimp and bacon). The cat was very attentive while it was being assembled. 

After one hour and fifty minutes of generator time, we were up to 91% SOC and the charge rate had dropped to 26 amps. 

Gary from Pau Hana Travels, one of the organizers of this get together, was running the generator on his diesel pusher and I had just a few questions about his setup. His batteries are 24VDC. He has two hybrid inverters to power both sides of the 50 amp breaker panel and multiple solar charge controllers. They are set to 24VDC (obviously). Two DC-DC converters are needed. The first is a 24-12VDC converter to operate the standard 12VDC systems on the RV. The second is a 12-24VDC converter for charging the batteries from the engine. I believe the current rating of the DC-DC converters is 70 amps with a claimed efficiency of 98%. The generator was switched to start and run off of the engine batteries instead of the house batteries. A completely separate solar system keeps the chassis batteries topped up. The way it is currently set up, only one of the hybrid inverters is set up to charge the batteries. The current set up is 65 amps. This could take 5-6 hours to charge the 500 amp-hour battery bank when it’s run down to 20%. I believe to use both inverters for charging requires only a software change. The maximum charge rate for the LiFePO4 batteries is 1C or in their case 500 amps. “C” is capacity. I believe that the max charge rate for lead acid is around 0.15C. 

I was really intrigued by his non-standard installation. He said that he would do a 24VDC system again. 

Lots of generators running as even those who have tons of solar aren’t able to charge their batteries due to the shade. Also, it’s 81°F and many are running their air conditioner(s). Our neighbor has an old class C with only one house battery. And a 110VAC only refrigerator so he is running his generator almost continuously during the day. Yesterday while we had visitors, he went out of his way to run it as little as possible but it is hot. It probably has the stock converter (battery charger) which means that it could take days to charge up the one battery and only 2 1/2 hours to discharge it while running off of the inverter. 

What I found interesting is that this couple was not alone having the idea of picking up an old RV just for their trip to AK. They were afraid of ruining their full-time living fifth wheel RV on the drive up. They believed all of the exaggerated myths and tales of broken frames, glass, tires, etc. They mentioned that next time, they would just bring their RV. 

There are also some who thought that the TOW highway was horrible and drove it at 10 mph. That makes for a long, dusty trip. 


  1. So, the feline is behaving? No cat-astrophy?

  2. Cat-astrophy.....I like that.

    As to converting everything to 24 Volts....oy.

    1. The 24 VDC was fro the batteries, hybrid inverter, and MPPT charge controller. Everything else remained at 12VDC.