Battery size 100ah?

I want to power 6 led puck lights, max air fan and a chinese diesel heater and a small TV. I currently have 200 watts of solar and 30amp charger. I found a good deal on a 100ah AGM battery. Should I get a bigger battery or would this be enough?


Heating, cooling, cooking, & refrigeration that use fuel only and no power are the best choices. 100ah of battery is a very minimal system, and so is only 200 watts of solar. Even 300 watts of solar would be questionable in the winter, WITHOUT the added load of that heater.

I would want at least 200ah-300ah of battery capacity with that heater, and I sure wouldn’t rely on solar to keep them charged during the winter. An isolator, a generator, or shore power are all better choices. Days are short and the sun is low in the sky during the winter, add in cloudy, rainy, or snowy weather and solar is the worst option available. Even in the summer, parking in the sun so your solar panels will work is pure torture.

What’s your plan for when it’s below freezing outside, you’re snowed in, and your battery(s) are dead, so your heater won’t work? This kind of stuff can and does happen all too often. Will you be prepared? There are heaters available that require no power, only fuel, including ones with thermostats, and they come in both portable & wall/door mounted types. Popular and/or highly promoted doesn’t always blend well with practical. Power is a luxury that shouldn’t be relied upon in this lifestyle.

Camping/Tent heaters usually require no power…


"It's always easier to conserve power than it is to create it." ~ Off Grid

You should double your battery bank. With a 100ah AGM you only have 50amps of usable power before you possibly damage the battery. You can power most of what you have no problem. Some days will be rainy or you might be in the shade of a tree and while you’ll still make power it won’t be enough.

If regards to your tv. Consider an ipad or some other tablet that can be powered through USB (preferably USB-C). We use an ipad pro for our tv (the larger size). It may be a bit expensive, but well worth it in my opinion. This way you won’t need an inverter to run it and they can last a long time on a single charge without constantly drawing power.

We have pretty much the same setup, 2 100ah AMG’s + 300 watts of solar. The only difference is we have a fridge and a propane heater. That being said, with an additional battery I think you’ll be pretty solid.

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I plan on buying a isolator. After reading what you guys had to say i am going to pick up a 200ah mighty max agm today. Really appreciate the input van dweller!

I am going to go with 200ah now after what you guys have said. I planned on getting a 12v tv or converting one to 12v. Would they still draw alot of power? I plan on getting something like a 24".

Look at the specs on the back of the TV, or its power supply. It will tell you in amps or in watts, but if it’s in amps at a different voltage than 12 or 14 or so, then you have to turn it into watts, then turn it back into amps at 12 volts.

For example, if the TV runs on 2 amps at 25 volts, multiply the two together to get 50 watts. To get amps at 12 volts, divide 50 watts by 12 volts to get 4.2 amps (amps at 12 volts), but since DC to DC converters are not 100% efficient you’ll probably want to go with 5 amps.

If you’re lucky and find a TV that runs on 12 to 16 volts or so, you might be able to plug it directly into your 12 volt system without a voltage converter. Most LED flat screen TVs run on DC, so look for one that runs on 12 volts or so. Might work.

So I have two batteries in my van. It is a 7.3 diesel ford which comes with two batteries. I just ordered a isolator and am confused which battery to wire it to?


I’m not real familiar with your particular system, but if it is similar to what I’ve had in buses you can hook up the isolator to either battery and it will be fine.


"It's always easier to conserve power than it is to create it." ~ Off Grid

One of the great things about internet: whatever you think of, someone else has already done that.

I know that Philips makes 230V/12V televisions in 22 and 24 inch sizes. I did not find anything useful regarding their power usage right now, on the pdf manual it states “20W”. Those Philips ones come with IPS screen, much better than TN which is usually found in the cheapest 12V models.