Thanks for the response. You are correct that lithium batteries are tricky to charge. My other hobby is model aircraft which has switched over from gas to electric in the past ten/fifteen years. I have several electric plans which use lithium batteries and have a special charger which watches each cell when they are being charged. For those reading this that are not familiar with these types of batteries the come in multiple cells, aligned in series to obtain the desired voltage. Using these for our QRP rigs brings up other issues I sure has been discussed else ware in this forum.
That being said, the Anker battery has built in circuitry to charge the battery which performs these tasks internally. All it requires for an input is 12 volts and up to 1 amp of current source. I’ve done some measuring of the battery as it’s being charged and have noted the wall charger that comes with the battery sources 12.2 volts and 1.2 amps, when the battery is being charged (under load).
My ultimate goal is to be able to charge the battery off of a solar panel. Using a solar charge controller I can guarantee a constant 13.6 (14v) power source, 2 amps max with my solar panel.
Playing around with a variable power source and a simple LM317 12v regulator I was able to charge the battery, even when the voltage dropped down to 11volts (note the current draw as 1.25 amps – which it appeared to max out at)
I enjoy wilderness camping for up to ten days at a time in length, thus the need to charge the battery using solar. I was just looking for a product to use or plagiarize the circuit off of.
Thanks again– Peter N0GRM