{"id":604,"date":"2024-04-24T18:00:08","date_gmt":"2024-04-24T22:00:08","guid":{"rendered":"https:\/\/thesolaraddict.com\/?p=604"},"modified":"2024-04-25T06:32:10","modified_gmt":"2024-04-25T10:32:10","slug":"how-big-solar-panel-recharge-rv-battery","status":"publish","type":"post","link":"https:\/\/thesolaraddict.com\/how-big-solar-panel-recharge-rv-battery\/","title":{"rendered":"How Big Do Solar Panels Need To Be To Recharge RV Battery?"},"content":{"rendered":"

Recharge Your RV Camper Batteries With Solar Panels<\/h2>\n

I travel fulltime in my RV, and I like to spend time out in the boondocks. I boondock 95% of the time, which means that I have no hookups, not even water.<\/p>\n

A big reason that some people have trouble boondocking for an extended amount of time is that their batteries run low. A great rule of thumb is to keep your deep cycle lead-acid batteries above 50% state of charge, and if you run the 12V water pump, furnace, and lights in your RV camper, it won’t take long until the battery indicator says it’s at 1\/2.<\/p>\n

Related Post: Best Solar Panels For Prewired Zamp Trailers<\/a>\u00a0\/ Use Panels With A Furrion Solar Port<\/a><\/strong><\/p>\n

Some people run their furnaces all night and wake up with a dead battery, then wonder why they have to buy new batteries every year.<\/p>\n

What I ended up doing was buying solar panels, but how many solar panels do you need to recharge your RV batteries? Let’s talk about it in an easy to understand way.<\/p>\n\n

How Big Are Your RV Batteries?<\/h2>\n

How many solar panels you need, or how big it needs to be, depends on how big your battery is.<\/p>\n

If you have upgraded your RV batteries to AGM, then you probably know how many amp-hours it is, meaning the battery capacity in amp-hours. If you have no idea how big your batteries are, I recommend reading this post over on KOA<\/a>.<\/p>\n

In short, your battery might not tell you how many amp-hours it can store, but if you can find the reserve capacity (RC), or how many amps it can deliver for X amount of hours, you can find out with some math.<\/p>\n

If you have the RC number, multiply it by 60 percent, for example, 100min*0.6=60Ah.<\/p>\n

If it tells you how many amps it can deliver for how many hours, you’ll just multiply the two. For example, 5 amps for 20 hours = 5*20=100Ah.<\/p>\n

We can also turn these amp-hours into watt-hours. 100Ah*12V=1200Wh.<\/p>\n

It’s very possible that you have two 12V batteries wired in parallel. This means that there is a connection between both positive terminals on the battery. Then there is also a connection between the negative terminals, separate from the positive.<\/p>\n

What this does is that it doubles the amp-hours. So if you have two 50Ah batteries, you have 100Ah capacity in total. If you have two 125Ah batteries in parallel, you have 250Ah battery capacity, and so on.<\/p>\n

Not all RV batteries are connected in parallel. If they’re connected in a different way, it might be 6V batteries. You can connect two 6V batteries in series to create a 12V battery system, or two 12V to create a 24V.<\/p>\n

In that case, there is a cable going from the positive terminal on one battery to the negative terminal on the second battery. Then your amp-hours don’t double, but the voltages do.<\/p>\n

So How Big Should My Solar Panel Be?<\/h2>\n

I believe it’s a good idea to be able to recharge your batteries fully in a day full of sun. The sun is the strongest around noon, so this is when you’ll generate the most electricity. However, it’s great to use every single sun hour of the day since it will help towards recharging our battery fully.<\/p>\n

A 100W solar panel, like the Renogy 100W<\/a> (I own two of these) generates about 6 amps per hour (6-80 watts) during the peak sun hours of the day.<\/p>\n

So if you have a 100Ah RV battery, you can charge 50% of it in a little over 8 hours (50Ah\/6A=8.33). 50 is 50% of our 100Ah battery, and 6 is how many amps the 100W solar panel is generating.<\/p>\n

In this video, I show the Renogy 100W panel and how to connect it to a camper.<\/p>\n