Battery Runtime Calculator

Thor

Thor

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I made a battery runtime calculator from a formula I found here on MYBB, I'll fetch the thread now now ( on my phone so search is iffy )

Let me know what you think and what other options I can add, battery types and inverter types, if needed.

erikthiart.com

Battery Run Time Calculator Using Watts

Use this battery run time calculator to determine your run time or the battery size that you need for your use case.
erikthiart.com erikthiart.com
 
Looks good Thor! A dumb question, but if your inverter is 24V … that means you have to get 2x 12volt batteries right? And then if each battery is 100AH, you then have a total of 24V and 200AH?
 
Foxhound5366 said:
Looks good Thor! A dumb question, but if your inverter is 24V … that means you have to get 2x 12volt batteries right? And then if each battery is 100AH, you then have a total of 24V and 200AH?
Click to expand...

2 x 12V 100Ah in series will be;

24V 100Ah

2 x 12V 100Ah in parallel will be;

12V 200Ah

Both will be;

2400Wh ( 2.4kw power source )
 
Nice, Except a little known voltage loss factor from Silicon of 0.7v and 0.3v for Germanium. it's a higher wattage loss for 12v systems vs 24,48,96.
 
As an inverter noob, I’m not sure what makes a quality inverter. Are all those Mecer inverters used in battery trolleys also quality wall-mountable inverters in your calculator?
 
Foxhound5366 said:
As an inverter noob, I’m not sure what makes a quality inverter. Are all those Mecer inverters used in battery trolleys also quality wall-mountable inverters in your calculator?
Click to expand...

I added a special drop-down for them now, they fall between Cheap and Wall mounted

± around 80% efficiency
 
Really that inefficient?

Also not clear what dod you're going to on lithium... Read the notes and it explained the thought process but not the assumption.

Common setup:
24 x 100ah using an axpert...
you say 3 hours 11 mins say 3.2 hours at 500W

so 2400Wh / 500 = 4.8 hours.
So you're losing 33% / getting 66% out of batteries out of DoD and efficiency.
So if we are using 80% DoD -- that would leave us with 83% efficiency. Not crazy I guess.

Does mean it is time to check my efficiency on axpert and revovs!

I expect lots of the quoted poor efficiency is down to them being designed with lead acids which are inefficient at charging... Lithium should be better.
Efficiency we care about here is the discharge efficiency rather than the recharge efficiency though... Sorry talking myself out of that last point!
 
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