7.6.2 Contingency Selection We would like to get some measure as to how. The idea of a performance index (PI) for line outage on line i seems to fulfill this need. Interrupted after one iteration (one P−6 calculation and one Q–V calculation;.
Here are your options. 9v alkaline: 9v @ 350-400mAh = 3.6Wh @ 90% buck converter efficiency = 3.24Wh = 6hrs @ 5v 100mA draw. 9v NiMh: 8.4v @ 250mAh = 2Wh @ 90% = 1.8Wh = 3.6hrs @ 5v 100mA draw. AA NiMh: 1.2v (x2) @ 2000mAh = 4.8Wh @ 75% boost converter efficiency = 3.6Wh = 7hrs @5v 100mA draw. 9v LiIon: 8.4v @ 550mAh = 4.6Wh @ 90% buck eff. = 4.158Wh = 8hrs @ 5v 100mA drawEDIT:If you don't mind getting a charger another option which is kind of cool is to use two 14250 cells.
These can be stacked into a single AA carrier to provide 7.4v nominal at 1Ah. That allows the use of the more efficient buck converter and for Vout of 5v, a Vin of 7.4v allows for near maximum efficiency of 90-95% typ. Working out the numbers, this will give you a run time of nearly 14 hrs (5v 100mA) in the space/weight of a single AA cell. If you want to go larger than a AA, the 18650 Li-Ion cells are a very popular choice. You'll need a charger, but you'll also get the following run-time out of one:3.7v @ 3400mAh = 12.58Wh @ 90% = 11.322Wh = 22.64hrs @ 5v 100mA drawBe sure to get one with an overcharge/discharge protection circuit though. Lots of customers like to use these batteries with complex protection circuitry built-into the device (like flashlights), so not all of these batteries come with the protection circuits. You'd probably be better off using 2 x AA batteries and a 5v boost regulator likeA standard rechargeable AA battery may have around 2000mah of capacity and a nominal voltage of 1.5v.
2 AA batteries will give you about 3 watt hours of juice, the boost regulator is around 70% efficient so we'll call it 2.1 w/hr. The pi zero will pull between 60ma at idle and 150ma at load, we'll say the average is 100ma and that means at 5v it is using 0.5 watts. 2.1w-hr/0.5w = 4.2hr This means the pi zero would last a little over 4 hours on 2 AA batteries. (this is mostly if you're considering rechargeables):seconded on the AA idea. For comparison a nimh 9v usually has about 150200mAh, which means quite a bit less than two AA's. Not to mention the price difference, and requiring a 9V charger. On a nimh AA cell the voltage is a bit lower, but you typically can find 2500mAh batteries that make up for the lower voltage and get similar or even higher total energy.lipos as mentioned would give you potentially sleeker form factors (e.g.
A 8501000mAh lipo pack would contain about the same energy but are much thinner than the 2xAA pack) and there's a lot of charger circuits out there to do the charging + system powering of your circuit. However, the initial costs of all the components would be higher, and you won't have the ability to swap them out for non-rechargeables that are widely available.