How Long Will A 200Ah Battery Last? Lithium, Deep Cycle (+ Calculator)

How long will a 200ah battery last? This is quite an interesting question. Luckily, if you know a few specs, you can quite easily estimate the 200Ah battery running time.

We are going to look into how long different 200Ah batteries last; including the 200Ah lithium battery (12V 200Ah LiFePO4 battery, for example) and 200Ah AGM deep cycles batteries. On top of that, we are going to include the 12V, 24V, and 48V battery running times for different wattage devices (100W and 400W, for example) as well.

200Ah batteries will last from anywhere below 1 hour (running 2000W devices) to over 200 hours (running 10W devices).

To help you out, we have prepared a 200 Amp-hour Battery Run Time Calculator (insert voltage, discharge rate, and wattage of the device you want to run, and the calculator will estimate how long will such a 200Ah DC battery last). Below the calculator, you will also find a 200Ah 12V Lithium Battery Run Time Chart and 200Ah 12V AGM Deep Cycle Battery Run Time Chart for devices between 10W to 3000W.

how long will a 200ah lithium ion battery last
Example of the kind of results you will get: This 12V 200Ah lithium-ion battery can run a 500-watt device for 4.32 hours (4 hours and 19 minutes).

Note: The calculators and accompanying 2 charts will help you immensely. If you still don’t find the answer using these tools, you can use the comment section below, give us some numbers, and we will help you calculate the 200Ah battery run time.

To calculate how long 200Ah batteries last to power electric devices, we need to know only these 3 metrics:

  1. 200Ah Battery Voltage. Most batteries will have a 12V voltage; a 12V 200Ah battery has a 2400Wh battery capacity. 24V 200Ah battery has a 4800Wh battery capacity and 48V 200Ah battery has a 9600Wh battery capacity; these 24-volt and 48-volt batteries can last 2-times and 4-times longer than 12-volt 200Ah batteries since they have double or quadruple battery capacity, respectively.
  2. 200Ah Battery Depth of Discharge or DoD. 200Ah batteries don’t actually give out 200 amp-hours. 200Ah lead batteries, for example, have only a 50% depth of discharge rate; that means they can give out 100 amp-hours. Depth of discharge rate is a measure of how much out of 200Ah capacity can a battery actually give out. Here is the nominal depth of discharge rates for different types of batteries (we will need this in the calculator below):
    200Ah Battery Types: Depth of Discharge (DoD): Usable Amp-Hours For 200Ah Batteries:
    Lithium Battery (LiFePO4 Battery) 80-90% DoD 180 Amp-hours (180Ah)
    Lead Acid Battery 50% DoD 100 Amp-hours (100Ah)
    AGM Deep Cycle Battery 80% DoD 160 Amp-hours (160Ah)
    Gel Battery 75% DoD 150 Amp-hours (150Ah)
    Renogy 200Ah Battery 80% DoD 160 Amp-hours (160Ah)

    Of course, we also need to be aware that the depth of discharge diminishes with cycles. Example: According to ScienceDirect, a gel battery will have a 75% DoD after 1000 cycles. A new gel battery will have a DoD of 80% or even more, and a very old 5000+ cycles gel battery will have a below 70% DoD.

  3. Running Device Average Wattage. How long will a 200Ah battery last obviously depends on how energy-intensive device we are powering (wattage). Obviously, a 200Ah DC battery will power a 100-watt device 4-times longer than a 400-watt device, since a 400W device has a 4-times higher power draw.

We can use these 3 metrics to calculate how long will a 200Ah battery last. Here is the 200Ah battery running time formula that we will use:

200Ah Battery Running Time = 200Ah × Voltage × DoD / Device Wattage

Here is a quick example: Let’s say we have a 200Ah 12V lithium ion battery (with 90% DoD – 0.9 factor) and want to run a 100W device. How long will this 200Ah battery run a 100W device? Just insert these metrics in the equation like this:

200Ah 12V Lithium Battery Running Time (100W) = 200Ah × 12V × 0.9 / 100W = 21.6 Hours

Here you have it: A 200Ah 12V LiFePO4 battery will run a 100W device for 21.6 hours (21 hours and 36 minutes).

This is just one example. To avoid this manual calculation (maybe a bit complex), you can estimate the running time of any 200Ah battery running any device by using this following calculator:

200 Ah Battery Run Time Calculator

In this calculator, you just insert the voltage of your 200Ah battery (usually 12V), depth of discharge (usually 80% or 90% for lithium and deep cycle batteries), and the wattages of the device you want to run with the battery. The calculator will estimate the running time automatically (you can play around with the numbers to see how the resulting running hours change):

Here is how this calculator works:

Let’s say you have a 200Ah AGM deep cycle battery producing a 12-volt DC current. How long will it run on a 400W device? Just slide the 1st slider to ’12’, the 2nd slider to ’80’ because we know AGM deep cycle battery has an 80% DoD from the chart above, and the 3rd slider to ‘400’.

You get the result: A 200Ah 12V AGM deep cycle battery will run a 400W device for 4.80 hours (that’s 4 hours and 48 minutes).

With this calculator, you can estimate running time for pretty much any battery. You can also check out a similar calculator for a 100Ah battery running time here.

12v 200ah battery in solar setup
Solar battery bank connected into a solar setup.

We used it to check the running times for two of the most common batteries used in solar and for powering a house:

  1. 200Ah 12V lithium battery.
  2. 200Ah 12V AGM deep cycle battery.

The full results for running devices from 10 watts to 3000 watts are summarized in these two charts:

12V 200Ah Lithium Battery Running Time Chart

We know that lithium ion batteries (LiFePO4 or lithium iron phosphate batteries, to be exact) have an above 90% depth of discharge. Accounting for this factor, here is a chart for how many hours will a 12V 200Ah lithium battery last running devices from 10W to 3000W:

Device Wattage: 12V 200Ah Lithium Battery Running Hours:
10 Watts 216.00 Hours
20 Watts 108.00 Hours
30 Watts 72.00 Hours
40 Watts 54.00 Hours
50 Watts 38.40 Hours
60 Watts 36.00 Hours
70 Watts 30.86 Hours
80 Watts 27.00 Hours
90 Watts 24.00 Hours
100 Watts 21.60 Hours
150 Watts 14.40 Hours
200 Watts 10.80 Hours
250 Watts 8.64 Hours
300 Watts 7.20 Hours
350 Watts 6.17 Hours
400 Watts 5.40 Hours
450 Watts 4.80 Hours
500 Watts 4.32 Hours
600 Watts 3.60 Hours
700 Watts 3.09 Hours
800 Watts 2.70 Hours
900 Watts 2.40 Hours
1000 Watts 2.16 Hours
1200 Watts 1.80 Hours
1400 Watts 1.54 Hours
1500 Watts 1.44 Hours
1600 Watts 1.35 Hours
1800 Watts 1.20 Hours
2000 Watts 1.08 Hours
2500 Watts 0.86 Hours
3000 Watts 0.72 Hours

As you can see from the chart, you can now adequately estimate how long will a 12V 200Ah lithium battery last.

Example: Let’s say you want to run a 1500-watt space heater with a 12V 200Ah lithium battery. How long will this 200Ah battery run a 1500-watt heater? Just check the chart: A 12V 200Ah lithium battery will run a 1500W space heater for 1.44 hours (1 hour and 26 minutes).

Let’s have a look at a 12V 200Ah AGM deep cycle DC battery as well:

12V 200Ah AGM Deep Cycle Battery Running Time Chart

The key difference here is that AGM deep cycle batteries have a roughly 80% depth of discharge. Accounting for this 80% DoD, here are the running times for 200Ah deep cycle battery powering different wattage devices:

Device Wattage: 12V 200Ah AGH Deep Cycle Battery Running Hours:
10 Watts 192.00 Hours
20 Watts 96.00 Hours
30 Watts 48.00 Hours
40 Watts 54.00 Hours
50 Watts 43.20 Hours
60 Watts 32.00 Hours
70 Watts 27.43 Hours
80 Watts 24.00 Hours
90 Watts 21.33 Hours
100 Watts 19.20 Hours
150 Watts 12.80 Hours
200 Watts 9.60 Hours
250 Watts 7.68 Hours
300 Watts 6.40 Hours
350 Watts 5.49 Hours
400 Watts 4.80 Hours
450 Watts 4.27 Hours
500 Watts 3.84 Hours
600 Watts 3.20 Hours
700 Watts 2.74 Hours
800 Watts 2.40 Hours
900 Watts 2.13 Hours
1000 Watts 1.92 Hours
1200 Watts 1.60 Hours
1400 Watts 1.37 Hours
1500 Watts 1.28 Hours
1600 Watts 1.20 Hours
1800 Watts 1.07 Hours
2000 Watts 0.96 Hours
2500 Watts 0.77 Hours
3000 Watts 0.64 Hours

With the chart, you can now just read off the 200Ah 12V AGM deep cycle battery running times.

Example: How long with a 12V 200Ah deep cycle battery run a 1000-watt device? Just check the chart: A 200Ah deep cycle battery will run a 1000-watt device for 1.92 hours (1 hour and 55 minutes).

Hopefully, you now know how to calculate the running time for any 200 Ah battery. The calculator and both of these charts will help you quite a lot. If you still don’t find the answer you are looking for, use the comment section, give us some specs, and we will help you out with the running time calculation.

9 thoughts on “How Long Will A 200Ah Battery Last? Lithium, Deep Cycle (+ Calculator)”

  1. We have a 25.6 volt 200AH LiFePO4 batteries (2 of them hooked up together )

    We have a sump pump that is 12 volt and runs for 30 seconds 4 times an hour ( 2 minutes/hour )

    Why then did the batteries shut themselves off after 6 days?

    How do we calculate if we need extra batteries???

    • Hi Karl, alright, the 25.6V 200Ah battery would have a 5120Wh capacity (presuming a 100% discharge rate). That means it can run a 5120W device for 1 hour or a 1W device for 5120 hours, for example. You need to know what is the wattage of your sump pump when it’s operating for those 2 minutes per hour.

      In 6 days, you have 2 minutes/hour * 24 hours/day * 6 days = 288 running minutes; that’s 4.8 hours. Alright, if the average running wattage of your sump pump is 1000W, you would spend 4800Wh of capacity in those 6 days. Now, at 100% discharge rate, the initial 5120Wh battery capacity will cover that.
      However, LiFePO4 batteries usually have 90% discharge rate (realistically); that brings the capacity down to 4608Wh. That’s less than 4800W if you are running a 1000W sump pump. Hope some of these calculations help you out figuring out if you need extra batteries.

  2. We have 1600w 24v inverter and two LiFePO4 12v 200Ah batteries connected in series to make wattage 24v.
    How to calculate how long the batteries will run under certain load. Is it 200 x 12v
    (or 24v) x DOD / by Device Wattage.
    Thank you.

    • Hi Vedran, alright, one 12V 200Ah battery has a 2,400Wh capacity. Two of them will have 4,800Wh capacity – and since these are LiFePO4 – we can account for 90% depth of discharge. That results in 4,800Wh × 0.9 = 4,320Wh of usable electricity.
      Now, if you run a 1,600W device with these batteries, you can calculate how many hours such an inverter will run like this: 4,320Wh/1,600W = 2.7 hours or 2 hours and 42 minutes. Hope this helps.
      In that equation you have put forward, you use 24V since the voltages from both batteries add up.

  3. Hi Learn Metrics,

    Awesome info and explanations, thank you!

    If using an inverter to power these loads, can one then just multiply your calculations here by inverter efficiency (if known…) to determine overall run time?

    • Hi Kelly, yes, if you know the inverted efficiency, you can use it in the calculations. Example: If you have 95% inverter efficiency, just multiply by 0.95.


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