What can a 400W solar kit run in an RV?
Treat the kit as a daily budget and spend it on loads. These figures use the same assumptions as our calculator: a 12V bank at 12.8V and 75% real-world harvest from the panels.
Your daily budget
| Sun where you camp | Watt-hours a day | Amp-hours a day at 12V |
|---|---|---|
| Cloudy or winter, about 3 hours | 900Wh | 70Ah |
| Mixed, about 5 hours | 1,500Wh | 117Ah |
| Desert summer, about 6 hours | 1,800Wh | 140Ah |
What fits in 117Ah
| Loads, added up | Ah a day | Array the calculator asks for |
|---|---|---|
| Lights, pump, phones, fans, 12V fridge, TV, laptop | 57Ah | 200W |
| The same, plus a Starlink Mini | 77Ah | 300W |
| The same, with a Standard Starlink dish instead | 102Ah | 350W |
| 12V fridge, TV, laptop, Starlink Mini, furnace, CPAP | 102Ah | 350W |
| 12V fridge, TV, laptop, Standard dish, morning coffee | 110Ah | 400W, close to the limit |
Add a furnace to that last line and you pass the budget. At 135Ah (the full list with dish, furnace, CPAP and coffee), the calculator wants 500W, which is the 600W kit.
In cloudy or winter sun the budget drops to 70Ah, so the second line already runs short.
What does not fit
- A 13,500 BTU rooftop AC. On a warm night it uses about 65Ah for every hour of running. After the 57Ah line above you have 60Ah left, so less than an hour.
- A 12V rooftop unit at about 32Ah an hour gets you a little under two hours.
- A 5,000 BTU portable unit at about 13Ah an hour gets you between four and five hours.
What the kit leaves out
The 400W Starter Kit has two 200W panels, a Rover 40A MPPT controller with a BT2 module, cables and mounts. There is no battery and no inverter in the box. Rigid panels weigh 72 lb for the pair and flexible panels 42 lb, which matters on a light roof.
One Renogy Rego 104Ah gives about 88Ah usable at the calculator's 85%. That holds one day of the 77Ah line. Two days of that line needs 200Ah, and two days at 117Ah needs a 300Ah bank. Solar refills the battery; the battery decides how long you last when it clouds over.
A coffee maker or microwave also means an inverter, because the calculator counts about 1,500W peak for it.
Run your own loads in our RV solar and battery calculator to get the exact array, battery and parts list.
What you need
Want the full walkthrough? Read the complete guide.