Typical Voltages and Electrical Battery Charging Issues

[TheLooks]

You mentioned buying a 100 ah battery.....I hope it was a marine/rv battery or deep cycle type.

 

[Kevin D Pem]

Wow!
Long post to have missed so much.
A lead battery dead voltage is 12.0 anything less tells me a cell has shorted or fallen out of the circuit.

What is the converter voltage with the battery out of the circuit?

12.67 = full charge of a sitting disconnect battery! The converter voltage should be 13.6 minimum to fully charge the battery!

It is a slow charge at best at 13.6 so we are talking days not hours.

As I recall MD on a marine battery means deep cycle. You should make sure the battery is not a starting battery.

A rv fridge likely will not run with battery voltage of 12v.

The only way to make it thru the night on battery power is to start with a fully charged battery. Even then a furnace running the chance of making it thru with 100ah is a crapshoot.

 

[Woods]

A good point about the furnace fan. We slept with the door open (just screen). The heat was set to 68 and never came on. Heating requirement would be a whole new variable.

The Diehard is 100ah AGM battery. Running the truck for an hour or so in the morning and an hour or so before bed worked great. Using the Victron shunt, I would make sure nonessentials were off before leaving the camper (or going to bed). The Victron would usually say between 16 hours and 4 days left depending on the current load. With only sensors and refrigerator on, I would usually draw between 0.8 to 2 amps. Usually the batteries were about 80% in the morning and 80% upon returning for bed. I would charge the battery every morning and night until indicator said 100% and amps went below 2 amps. Extra battery capacity would be great. I don't camp without power very often and extra battery would take up cargo storage. So weighing the pros and cons. Thanks for all you guys help. The Victron gives a lot of visibility into the battery usage and charging. Using the converter / generator to charge did very little to actually charge the batteries. They would trickle charge until 12.6 volts and then stop per the pictures. I haven't checked the voltage with the batteries disconnected yet. I have a MagneTek 900 Series Converter. The Victron helped make this an awesome first trip of the year! I'll have maybe 2 more trips without shore power.

 

[Woods]

I plan to install the plumbing accumulator tank next month. The battery monitor and accumulator tank should be standard equipment. Dry camping is nothing but guess work without the monitor. Thanks again for all of your help! Looking back on all my adventures, I wish that I had never bought a new generator (mine went out). Only need enough power to run the microwave for 3 minutes each day. $5000 for a bag of microwave popcorn is too much! Maybe the generator would be useful, if the converter actually had the power to charge my batteries in a short amount of time (like the truck). I can't stand to hear the generator run continuously for days to slowly trickle a battery charge. I might spend even more on this money pit and get a real converter / charger? Probably just make do!

 

[Bob K4TAX]

I plan to install the plumbing accumulator tank next month. The battery monitor and accumulator tank should be standard equipment. Dry camping is nothing but guess work without the monitor. Thanks again for all of your help! Looking back on all my adventures, I wish that I had never bought a new generator (mine went out). Only need enough power to run the microwave for 3 minutes each day. $5000 for a bag of microwave popcorn is too much! Maybe the generator would be useful, if the converter actually had the power to charge my batteries in a short amount of time (like the truck). I can't stand to hear the generator run continuously for days to slowly trickle a battery charge. I might spend even more on this money pit and get a real converter / charger? Probably just make do!

A $650 Champion generator, 2500 watt inverter, will do the job and save you $4300. If your converter won't charge the batteries, I'd say one needs to look at the type and size of the converter. Ours is a 50A-rated converter and will bring our batteries to full charge in less than 4 hrs., depending on the level of discharge.

Bob