A 12v 200ah battery will run an appliance that requires 200W for between **5.4 hours** (with lead-acid battery type, 50% DoD limit)** to 11 hours** (with lithium battery type, 100% DoD limit)

Keep reading I’ll explain how you can calculate how long will your 200ah battery run on a 200-watt appliance

## 200ah Battery Runtime Calculator

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### Assumptions:

**Inverter Efficiency:**90%**Lead-acid battery:**50% depth of discharge limit**Lithium (LiFePO4):**100% depth of discharge limit

**Battery Depth of discharge DoD:** is the percentage of the battery that has been discharged relative to the total battery capacity. The recommended depth of discharge limit for lead-acid, AGM, and gel batteries is about 50%. Only lithium (LiFePO4) batteries can be fully discharged to 100%.

### How To Use The Calculator

**Enter the battery capacity in amp-hours (Ah):**in this case, it’ll be 200**Enter the battery voltage:**is this a 12, 24, or 48-volt battery?**Select the battery type:**Select “Lead-acid” if you’re using a flooded or sealed (AGM or gel) lead acid battery. Select “Lithium (LiFePO4)” if you use a lithium-iron-phosphate battery.**load Connected with inverter?:**Are you using an inverter to run the load or is the load connected directly through the battery?**Enter total load in watts:**Enter the total load in watts (e.g 200 for 200 watts of output load)

After entering the information, click** “Calculate” **button to find out how long the battery last running a load.

### Example

## Video – battery 101: Must watch!

## Steps To Calculate 200ah Battery Runtime On 200-Watt Appliance

Follow these steps to calculate the battery life/runtime while running a load.

### Steps

**1- Converter battery ah into watt-hours (Wh)**. to calculate the battery capacity in watt-hours use this formula

**Battery capacity in watt-hours **= Battery amp-hours (Ah) * Battery Volts

let’s say you have a 12v 200ah battery

`200ah battery in watts = 200 * 12 = 2400 watt-hours `

**2- Multiply the battery watt-hours by the battery depth of discharge limit**. **( Default battery depth of discharge limit, Lead-acid battery: 50% DoD limit; Lithium: 100% DoD limit )**. Let’s say you have a lead-acid type battery

`Battery capacity in wh after DoD limit = 2400 * 50% = 1200wh`

**3- Multiply the battery capacity after the DoD limit with the inverter efficiency rate to calculate the AC watt-hours ( Most of the inverters are about 90% efficient)**

`Battery AC watts = 1200 * 90% = 1080 AC watt-hours `

**4- Divide the battery AC watt-hours by the total load connected. **Let’s say 200-watt appliance is connected to your 200ah battery

`200ah battery runtime on 200w appliance = 1080 / 200 = 5.4 hours`

## How Long Will A 200Ah Battery Run An Appliance That Requires 200W

here’s a chart on how long will a 12v, 24, and 48v 200ah lead-acid or Lithium battery will last on 200-watt load.

Battery Capacity | Battery Type | 200ah Battery Runtime on 200w |
---|---|---|

12v 200ah | Lead-acid | 5.4 hours |

24v 200ah | Lead-acid | 11 hours |

48v 200ah | Lead-acid | 22 hours |

12v 200ah | Lithium (LiFePO4) | 11 hours |

24v 200ah | Lithium (LiFePO4) | 22 hours |

48v 200ah | Lithium (LiFePO4) | 44 hours |

## Assumptions & Shortcomings of All These Methods

Here are some extra yet important points to keep in mind when figuring out how long your 200ah battery will last running a load

### Battery life cycle count:

- The storage capacity of the battery will decrease with every cycle ( a cycle is when you charge and discharge the battery to its DoD limit ).
- if you have used your battery for a few hundred cycles then the result will be different. ( this factor isn’t included in my above-given methods )

### 200ah lead-acid Batteries are rated for 10 amps over 20 hours of time:

- Especially lead-acid type batteries are designed to be discharged at 20 hours. ( means 200ah
**lead-acid batteries are recommended to be discharged @ 10 amps**in order to maintain the battery health and reduce the discharge efficiency ). - on the other hand,
**AGM and lithium (LiFePO4)**can be**discharged at 50% of their capacity**. - Discharging your battery at a higher rate will increase heat in the battery’s internal cells which will cause power loss. (this factor isn’t included in my above-given methods).
**For example**, if you discharge your lead-acid battery with 200 amps then it’s will not last 30 minutes ( keep in mind the 50% DoD limit ). but it may last about 15-20 minutes.- Check the battery discharge rate on the specs sheet of your battery or it’ll be mentioned on the battery
**(1h → 1C, 2h → 0.5C, 5h → 0.2C, etc.)**