3 ms·
No, Watts should be independent of voltage, it is the product of voltage and ampere (don't know the exact English terms here). You perhaps mean ampere hours, I
by raxxorraxor 4y ago
No, Watts should be independent of voltage, it is the product of voltage and ampere (don't know the exact English terms here). You perhaps mean ampere hours, I think that is often used for phones.
But it is only ever meaningful if you have the respective fixed voltage and it often make sense for a batteries to quickly calculate how long they should last if you know how much ampere a device draws. It could also become a sensible metric if we always talk about 120V/240V for general household appliances of course.
- thehappypm 4y agoI think what they’re talking about is the amp-hour measure of battery capacity, which is common in electronics, but converting to actual energy requires knowing the voltage.
- beckingz 4y agoVoltage isn't fixed across a discharge cycle. As a chemical battery discharges, the voltage drops, so at the same load in amps you get less watts later.
- raxxorraxor 4y agoedit: Wh is independent of voltage I mean... of course a product is dependent on its factors...
- vbezhenar 4y agoYou're right, I mangled Ah and Wh in my head, sorry. 4V 1Wh battery and 24V 1Wh batteries are equally useful. Your numbers are a little bit off though. I just googled some power bank (which is supposedly better than smartphone). It claims to provide 20 000 mAh at 5V. So it's 20 Ah at 5V or 100 Wh. I think most smartphones are around 10-20 Wh. Far from 5 kWh. But this discrepancy was already noted in other comments.