Hello all,

I am building a landline telecom system which would work on solar system independently without mains power. A huawei sim based wireless terminal device is to be powered by a solar system which consist of a 12v solar panel providing 2.08A of max current hooked up to a 12v/5A solar charger and a 12/10AH battery. Power supply to wireless terminal must be 5v/2A and to do that I am planning to use a DC to DC stepdown converter as shown below. I want to connect it between battery and solar panel.


The reason to use this module is that I didn't find any solar charge controller with continuous output during also day time. All of them comes with dusk to dawn function which can't give power during day time. There are some programmable which can fulfill this requirement but the are very much expensive.
So my question here is if I run my device using above module will it affect charging process during day time?
Will the solar panel provide enough power for charging battery and power on wireless terminal at the same time during day time?

Regards,
Shan.

 

... just guessing here, but the measurement of interest will be the usual average current that is generated on a daily basis by your solar panel. The maximum number is stated above, however that will not necessarily be what is actually generated ... a result of photo-cell efficiency, daylight hours, cloud cover, angle of sunlight incidence, dust build-up on the surface ... In what geographical region are you located? It would be interesting to put a dummy load resistor ... a 50 Ω cantenna resistor, as used for amateur radio might work ... on your solar panel and take hourly readings of current generated during daylight. ... Plot the hourly current readings, take the average value between each adjacent reading pair, and find the daily AH total. This will give an approximate number for the amp-hours that can be produced by the panel. If you can generate enough AH, then just add another battery or two, as necessary. Having some reserve AH available seems like a good idea.