Wednesday, November 27, 2019

Day 18 - Quartzsite, AZ

The new routine seems to be run the generator starting around 8 am for a couple of hours then again around 4pm for an hour. This is usually sufficient to charge the batteries up to over 90%. With lead acid batteries, the charger goes into absorption mode and the charging current drops significantly. From around 75amps to under 30amps. That last 10% takes a long time. I’m told that one benefit of Lithium batteries is that there is no absorption phase. Bulk charge at max current until they reach 100%. A nice feature.

Yesterday’s Sunset
Last year, we kind of did the same thing even with the 400watts of solar panels. The solar would leave us about 10% short every day. So, to get the most out of our generator run time, we would use the generator in the morning to get the batteries back up to about 85% then let the solar finish them off. This was before I upgraded the converter so max current while running the generator was only about 40amps.

By the way, note that the max charging rate on this RV is set to 83 amps. A commonly referred to max charging rate for lead acid batteries is 0.1c or 10% of the battery capacity. This bank is 430 amp-hours so the “commonly accepted” max charge rate is 43 amps. But, what is usually not stated is that the 0.1c number is for sealed lead acid or AGM batteries. For flooded lead acid batteries, the max rate is 0.2c to 0.25c depending on the battery construction. This coach and our 5th wheel both have flooded lead acid batteries golf cart batteries so the max charge rate ranges from 86 amps to 108 amps. I was initially concerned that the setting on the Magnum inverter/charger may ruin the batteries from the high charge rate. But after doing more research, not an issue.

The blinds over these windows in the above aren’t open very often. But they do let in a lot of light (and heat) and are one of the features of this RV that we like. This morning, I ran the generator a long time (3 hours) as the SOC was 58%. We started at 90% yesterday evening and ran the inverter and both furnaces until around 11pm. The rest of the night we just used the inverter and the rear furnace as it just heats the living space. The front furnace heats the storage bays and tank spaces in addition to the living room/kitchen area. I’ll run the generator again while I’m making dinner as I need to use the convection oven. It will run off of the inverter but sucks a lot of power. The 3 hours of generator running this morning only got the batteries up to 86%. Propane gauge is just a little under ⅝.

I went to the local grocery store and it was very busy. Four checkers all of them with lines! I must not be the only one with a last minute shopping list...

Happy Thanksgiving!

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