How Long Will a 100ah Battery Run a TV?

Watching TV is a part of life for many, so figuring out how much solar power it consumes is necessary. Because solar panels cannot produce power at night, batteries are required, but how long will a 100ah battery run a TV?

A 12V 100ah AGM battery with a 50% discharge rate and an 85% efficient inverter can power a 120V 50 inch TV for approximately 3 to 4 hours. A 12V TV for campers running on the same battery will last for 12 to 15 hours depending on how many amps are drawn per hour.

Calculate Solar Battery TV Requirements

The most important factors that determine how long a battery can run a TV are the battery capacity, discharge rate, the TV voltage, watts and amps drawn per hour.

To find out how long a 12V 100ah battery can power a TV, use this formula:

TV voltage / watts = amps drawn per hour / inverter efficiency percentage

From here you can calculate how many hours the battery will last, factoring in the inverter efficiency. The higher the efficiency rating, the longer you can run the appliance.

For instance, a 50 inch 120V LED TV consumes 100 watts. 120 volts / 100 watts = 1.2 amps drawn per hour. Divide that by .85 for the inverter efficiency and it becomes 1.4.

However the TV is 120 volts, so 1 amp at 120V becomes 10 amps at 12V. 10 amps per hour means a Renogy AGM 100ah battery for instance, can run a 50 inch for 10 hours before it is completely drained. But AGM batteries have a 50% depth of discharge rate, so the runtime is cut down to 5 hours. Add the 85% inverter efficiency rating and you get around 3 to 4 hours.

The majority of household TVs are 120 volts, so the calculations above are valid. However the watts differ depending on the type. Examples:

• 30 inch LCD TV: 60 watts
• 30 inch LED TV: 50 watts
• 42 inch LCD TV: 120 watts
• 42 inch LED TV: 80 watts
• 50 inch LCD TV: 150 watts
• 50 inch LED TV: 100 watts

These figures are for 120V TVs. There are smaller, 12V TVs available including the 19 inch Jensen JTV, and these are commonly used in RVs. These appliances consume much less power and are more efficient.

A 20 inch 12V TV for RV may consume 35 watts only, which means a running time of 12 to 15 hours on a 100ah battery. Most of these are in the 20 to 32 inch range, which is fine for RVs. If you want a power saving TV then you should consider these. Note that there are also compat TV sets for homes available.

Which Battery is Best For TV?

If you want to power a TV with solar panels, you know the panel size makes a big difference. When it comes to batteries, it is the depth of discharge (DOD) that matters.

Lead acid batteries, AGM, gel, SLA have a 50% DOD. If you have a 100ah lead acid battery, you should only use 50ah before recharging. You can drain it to 0%, but it will not be good for the battery’s life cycle.

Lithium batteries cost much more than lead acid, but the tradeoff is a better discharge rate. The average is 75%, but high end batteries can be discharged to 90% or 100%. Even if your lithium battery does not provide 100% DOD, you can expect at least 70%.

Going back to our calculations, with an AGM battery the best you can get is 3 to 4 hours for a 120V 50 inch TV. But with lithium you get 5 to 6 hours. The runtime also doubles for 12V TVs. This runtime will go down if you connect peripherals, but the point is you get more power out of the same battery size.

Does that make lithium battery better for TV? It depends on your usage. If you binge watch regularly and find yourself recharging the battery repeatedly, it is time to go with lithium. But if you only watch a few hours just before you go to sleep, then lead acid batteries will be fine.

You also have to consider your entire setup. For the purposes of this guide we have been focused on TV usage of batteries. In the real world your battery will be running other appliances and devices.

You have to decide if you are happy with what your battery setup is providing. Most use lead acid because it is more affordable. If you are satisfied with it, that is great. If you find it is lacking, then maybe it is time to upgrade to a lithium battery bank.

How Many Batteries For a Home Entertainment System?

So far we have concentrated on the TV alone, but most of us have peripherals and accessories that go with it. And that will increase the power consumption and battery requirements.

The following are some of the most popular home entertainment components and their power consumption. These are ballpark figures and will vary depending on the manufacturer, specs and so on. Check the product manual or website for more specific details.

• 5.1 channel home theater with subwoofer: 250W
• Video game console: 90 to 100W
• Blu-ray player: 130W
• Set top box: 10W to 40W

The biggest power draw is no surprise, a home theater system. You won’t be using these in an RV, but if you fancy installing one in your solar powered home it is going to consume a lot of power. A 100ah battery will not be enough.

A set top box will shorten the running time a bit, but the bigger impact will be from a Blu-ray or a gaming console. Bottom line: you need more than a 100ah battery if you want to equip your TV with a video game console or a movie player. There are many options available including the Mighty Max 12V 100ah which should be enough in this case.

Granted thee are more efficient gaming consoles available, but the biggest challenge is the runtime. One can end up playing video games for hours, and before you know the battery has run out. If you are a gamer, you have to get a high capacity battery bank that can keep going for several hours.

Can I Connect Two or More 100ah Batteries?

In a previous post we showed how you can convert 12V solar panels into 24V. Well you can increase the power of a battery by connecting it to another and forming a battery bank.

By connecting batteries in parallel, their amps increase. Connect two 12V 100ah batteries in parallel and you get a 12V 200ah battery bank. This is a good option if you want to power your TV along with a video game console or another peripheral.

To connect two batteries in parallel, connect the positive terminal of one battery to the positive terminal of the other battery. Repeat this wit the negative terminals.

In a series connection, the amps remain the same, but the voltage increases. Connect two 100ah 12V batteries in a series and the result is a 24V 100ah system. You can configure batteries in a series by connecting the positive terminal to the negative terminal.

In our example a parallel series is better because we want more power. But there may be instances where high voltage is required.

In theory there is no limit to the number of batteries you can connect together. However the more batteries in a bank, the greater the risk of malfunction.

The larger the battery bank, the harder it is for the current to reach each one and provide the proper amount of power. If an imbalance occurs it might affect the entire system performance. it is better to connect a few large capacity batteries than several smaller ones.=, especially if you have a large solar system.

Can I Use Solar Panels and Batteries to Run a TV?

Yes you can combine solar panels with batteries. In fact that is how most off the grid systems work. The solar panel charges the battery and appliances run off the battery bank and inverter.

A 100W solar panel can in theory provide 100 watts an hour. But that only happens in perfect weather. You are better of with a 120W or a 150W panel, which should work well with a 100ah battery.

A 150W solar panel and 100ah battery will work for a TV, but you need a bigger solar system if you have to run other appliances. In an off the grid home you have to run everything including the refrigerator, heating / cooling etc. without the aid of a power grid. Which is why most of them have a generator as backup.

You will also need an inverter to run the system. Most inverters have at least 1000W capacity so that won’t be a problem. Technically TVs run on DC and you may be able to connect it directly to the solar panel. But we do not recommend that as it might cause problems.

Unless you only use the TV, you will be using other appliances n your home or RV, almost all of which run on AC power. This is why you need an inverter because solar panels produce direct current energy.

Conclusion

The good news about running TVs on solar is one, modern units are energy efficient, and two, a growing number are now designed with renewable energy in mind. Even if you do not have a solar powered TV yet, you can use the regular set without problems.