#9 Evaluation of standby power sources/battery storage

Following a donation of the following equipment

1x BlueSolar MPPT 75 I 15 charge controller – brand new still in packaging 1x Powerfilm 14W solar charging panel 2 x Powerfilm 60W solar charging panel

Together with our current holdings of Solar panels of various vintages/sizes, evaluate what the best fit may be for RAYNET operations in the field.

There are loads of battery sizing spreadsheets out there but do they align with the duty cycle of a RAYNET outstation? Or a talkthrough site?

Donated equipment stuck with G1GQJ during COVID-19 lockdown.

Add into the evaluation the 50W Banggood foldable solar panel at https://www.banggood.com/Portable-50W-12V-Solar-Panel-Waterproof-Folding-Charger-Outdoor-Hiking-Mobile-Power-Bank-p-1458974.html?rmmds=myorder&cur_warehouse=CN and the now ‘old’ Maplin 13W ‘Solar Suitcase’ https://maplindownloads.s3-eu-west-1.amazonaws.com/N00CX-instructions-3716.pdf which weighs more ( 4.5kg ) as examples of ‘power to weight’ ratio.

New wrinkle to consider…. The 50W Banggood panel only appears to produce 14.5V open circuit voltage in daylight. This is less than the 15V needed to trigger some solar charge controllers. Probably down to the USB charging circuit built into the solar panel. The effect was apparently to lose about 3 hours of potential charging time until I noticed the charger wasn’t working and blocking any current going to the battery.