battery sizing calculator 12v

January 15, 2026 - Battery Run Time Calculator. This sizes a 12-volt battery while factoring in a 50% depth of discharge to prevent you from excessively discharging the battery.

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Battery size calculator | jCalc.net

March 3, 2018 - The battery size calculator calculates the battery size in ampere-hour (Ah).

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Battery Size Calculation Check

This looks like valid math. However, lead acid batteries are recommended to not be drained below half their capacity, so you may want more battery power. And don't expect a cheap inverter to run continuously at full load for three hours. Get a 1000W unit. More on reddit.com

r/ElectricalEngineering

September 20, 2023

Is there a good calculator for estimating size of battery and inverter for an off-peak, non-solar system to charge battery during off-peak times and run house during peak times? I’d add solar later.

You need to identify your power consumption during the peak rate time you want to avoid. This will define the storage capacity of your battery system Also identify the circuits that will be powered by battery. This will determine size of your inverter. (For example: air conditioning, water heater, electric range. But not dishwasher, cloths dryer or cloths washer, etc because will not use during peak times More on reddit.com

r/SolarDIY

July 2, 2022

Trying to decide what battery size I need. Is there a calculator or spreadsheet I can use? What size do you typically use? Charging phones, laptops, a drone, running a dometic, lights in camper to see.

Just going through this process atm myself! It sounds like you don't have any large draw items listed, but do weigh how likely or unlikely you are to want to add to that list and consider leaving headroom in your battery bank to cover it, especially for inefficiency losses. Some questions to clear up before moving on to deciding on batteries: Are you running solely 12V, 120V or a mix of both? If strictly 12V, this simplifies your wiring circuit and necessary protective and functionality hardware. If 120V or a mix of 12V/120V, you're stepping into the land of inverters and possibly a DC - DC charger so you can efficiently charge your extra battery(s) as you drive rather than relying solely on plug in 115V land power. Solar is a consideration for constant top up if you have the remote need, space and budget. How budget friendly are you looking for? If, like me, you're trying to maximally stretch your dollar, lead acid/AGM style batteries will be your choice over a lithium/carbon foam/etc build. This will also affect things like cabling size and overall cost as well. Weight is a huge factor here as lithium is around half the mass as well as DoD (Depth of Discharge). There's many free tools out there to estimate your capacity needs. I've mainly played with https://www.batterystuff.com/kb/tools/solar-calculator.html ? to get a good idea of what I'd like to aim for. More on reddit.com

r/TruckCampers

March 30, 2025

Built a solar battery sizing calculator - looking for feedback from fellow technicians

Your prices are all retail bought from a high markup vendor. I put my system in and ignored the installation price and you are still 50% higher than what I paid for the batteries and the panels. And you don't show the inverter anyplace so exactly where is the inverter? And if you are using micro-inverters and large batteries, then you designed you system BADLY (following Enphases lead where they later shoehorned batteries into their system and have the inverters doubled up--ie panels have inverters and the batteries have inverters, and their inverters are not price competitive with a large inverter BEFORE you add in the overpriced batteries). And your recommended equipment seems to be for a tiny/small systems and the hardware you use to build a tiny system with is not price efficient for a large system. You should probably call it a small system config tool. I don't know that ANYONE can easily provide a decent calculator that provides reasonably correct results for this sort of config. There are too many variables to handle. More on reddit.com

r/solarenergy

October 1, 2025

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