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Portable power station Ah equivalents at 12 V?

B.Babs

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May 6, 2022
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I've been having a tough time trying to figure out the rough equivalent in Ah capacity at 12 V of my portable power station? It is rated in watt hours. This is great because I know at 12V a full 100 Ah battery is roughly 1200 watt hours. I know from experimenting with a friends portable power station & my own inverter combined with a single 100 Ah BB lithium iron phosphate battery that my system runs for considerably longer? If they both have a similar watt hour rating? What gives?

The only thing I never see specified on a Jackery etc. is the internal battery/inverter voltage? Would this not be crucial data for determining the true capacity when calculating a direct comparison? between a 12V + 12v inverter system vs a portable power station? What am I missing?
 
Measure the capacity of each system in a consistent and controlled manner. Then compare the true capacities based on the observed results. Marketing department capacity claims are seldom trustworthy.
 
I found the information in the Jackery download manual under specifications. https://www.jackery.com/pages/user-guides
Jackery uses trickery. They inflate the Watt Hours by exaggerating the battery voltage. Example; Jackery 300. 293.8 Watt hours, 20.4 Amp Hour battery (times) 14.4 Volt battery. That is serious overstatement of normal battery voltage. 20 amp hour battery is tiny. But the 300 only costs $300
The larger units cost plenty more. 1500 has a whopping 60 Amp hour 25 volt battery, for a pittance, only $1700.
 
I found the information in the Jackery download manual under specifications. https://www.jackery.com/pages/user-guides
Jackery uses trickery. They inflate the Watt Hours by exaggerating the battery voltage. Example; Jackery 300. 293.8 Watt hours, 20.4 Amp Hour battery (times) 14.4 Volt battery. That is serious overstatement of normal battery voltage. 20 amp hour battery is tiny. But the 300 only costs $300
The larger units cost plenty more. 1500 has a whopping 60 Amp hour 25 volt battery, for a pittance, only $1700.
Is there a formula to figure this out?
 
Did you look at the specification page on that link? It is there. No math involved. Or ask a different question.
Watts are amperes times volts. Amp hours are watt hours divided by volts. If we take the amp hours of the battery and multiply it by more volts than is real the watt hours are higher than reality.
Take the watt hours and divide by 14 or 15 volts to estimate the battery amp hours. I think all those fake generators use the same trickery.

Keep in mind, watt hours are a poor way to describe battery storage. Batteries store amperes. Watts are energy used.
 
I wouldn't be so quick to call it trickery. To my knowledge, these are not lead-acid, nor are they LiFePO4, but typically use other li-ion chemistries in the nominal 3.7v range.

Many of these packs, kind of like power tool packs, can typically range from 16 to 20v or so. The solar charging circuitry can also be using buck/boost techniques, rather than what we would consider a typical 14.4v solar controller to charge those higher voltage batteries.

So yes, it just might meet specs. Zil - you need to buy one and find out for us.
 
B.Babs - here is the formula for power.

Usually it is represented as P/I*E or verbally "P over I times E". In many books it will be represented inside a circle cut into thirds for each element.

Know any TWO, and the third variable will be revealed.

Where P is in watts
I is in amps
E is in volts

But this is a stark calculation. Real-world variables, which usually include efficiency compensation, such as might come from regulators, inverters and whatnot to deliver end-user workable voltages, will change the overall calculation slightly.
 
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