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Making, storing, and using power wisely is important for happy vandwelling. Power issues can seem overwhelming and confusing; this article intends to lay out the basics.
Before we start: there are two generally-separate electrical systems in your self-propelled camper1):
Pro | Con | |
---|---|---|
shore power | cheapest per watt simple abundant power | often not available if available you are tied to the outlet by your cord/adapter campgrounds with outlets are more expensive |
solar | automatically makes power when the sun shines makes high voltages needed to fully charge lead-acid batteries silent lasts for decades | most expensive per watt can be complex panels are large output drops dramatically when shaded |
alternator | automatically makes power when driving about 1/10th the cost of solar for the same current output | relatively low charging voltage2) can result in chronic undercharging should not idle to charge most people don't drive enough to fully charge lead-acid |
generator | can make 1000w+ of 120v can run for days inverter models are quieter | can be expensive ($1000+) maintenance needs to be stored when not in use noisy not allowed in some areas/times |
Combined alternator+solar charging enhance each other when used together. The investment in solar can be significantly reduced.
Note: So-called solar generators do not generate power: they are battery banks, usually AGM or lithium. See below.
Power production tends to be heaviest during the day while power use tends to be heaviest overnight. This means power needs to be stored when power is abundant so it can be used later. The most common storage for power is in a deep cycle battery bank.
Pro | Con | |
---|---|---|
Flooded lead-acid (FLA) | cheapest per Ah most tolerant of abuse | lowest current throughput maintenance (“watering”) required can only use 50% of rated capacity3) |
Sealed lead-acid (SLA, AGM) | able to charge/discharge more current than FLA | more expensive per Ah4) cannot check or replace electrolyte |
LiFePO4 (LFP) lithium | very close to normal 12v ranges available as “drop-in” replacements for lead-acid current throughput can be more deeply discharged than lead-acid | most expensive upfront per Ah cannot be charged in freezing temperatures |
Non-LFP lithium | cheaper than LFP per Ah current throughput | thermal runaway voltage not well-suited for 12v systems |
The battery bank is sized to meet your daily power needs and as well as any extra margin you might like.
Using power is the simplest part. It's so simple the newbie may find themselves overdrawing from the available power. A low voltage disconnect (LVD) is one way to keep from overdischarging the bank.