Well today was finally a nice sunny day! And I’ll just say I am quite impressed with how much I got out of the Voltaic 3.5W 6V. Looks like from about 8:00 AM to ~ 4:00 PM it charged my 6600 mAh battery from ~2% --> ~80% in the 8 hours of sun today (obviously slower during the beginning of day and end of day). This was with the device in “normal” operation mode the entire time and not even in stop/sleep mode. I kept it that way so I could keep taking readings throughout the day to see how it’s doing. I suspect I would of had another 5-8% if the device was sleeping. Overall, I’m very impressed and happy with this!
If I’m thinking about it correctly, say I charged 80% of a 6600 mAh battery I stored away 5280 mAh in ~ an 8 hour period. So on average: 660 mAh battery capacity per hour of charging. I.e. averaged 660 mA charge current into a 3.7 V nominal battery. This is 2.442 average watts from that 3.5 watt peak Solar panel. ~70% efficiency on average throughout the day. Overall, I’m very happy with that! Thanks everyone for sharing the settings and the guidance here. Always appreciated. I’ll still implement the sleep cycles, and dynamically change charging parameters as discussed earlier but I’m quite please with this early test. I was getting nearly 1 week of battery life when keeping the device awake the entire time before a solar panel and roughly 3-4 weeks when using a sleep/wake cycle so Solar panel makes a huge difference! Just 1.5 days of sun during this a time period like this would charge it right back up! This is great!