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.

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.

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:

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: