Author Topic: MPPT in small solar chargers  (Read 2364 times)

Kavan

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MPPT in small solar chargers
« on: March 23, 2013, 10:54:36 AM »
Hello Forum,

Do small solar, portable chargers have a MPPT controller inside or not?

http://gigaom.com/2011/01/12/7-ways-to-charge-your-iphone-with-solar/

Why not? Is it because it is too expensive, bulky and only works with large voltages?

Most of these small chargers don't charge the device directly. They instead charge a battery pack which can later charge the device. Why? Why use this intermediate step instead of charging the device directly?

thanks,
Kavan

SeanB

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Re: MPPT in small solar chargers
« Reply #1 on: March 23, 2013, 11:13:55 AM »
The controller adds cost to the device, and it is easier to do charge control with other methods like voltage level monitoring. Charging a battery inside the device allows as well the convenience of being able to charge during the day when you want to use the phone or whatever, while doing the actual recharge later when it is convenient for you to do so. MPPT adds a complex inverter, doable at low power, but it will probably double the cost in a small device, where you already have high cost items like a solar panel and a battery using a majority of the production cost.