Kudos to the point of...
You are engaged in what many Y chromosome snorting males on this forum are themselves too timid to try.
I guarantee you it's like riding a bicycle. The few first solos are hair raising. But give it a bit of time and soon you will be doing hand stands on the handlebars.
I packed and transported the BORG 500 miles this month. Even though the unit has ten turn voltage adjustment, when I plugged it in, I found 12.3 volts on one Megawatt and 14.85 on the other.
Just plug it in and check voltage BEFORE clamping the battery cables onto the battery.
Voltage will ALWAYS be two or three tenths higher unconnected than with the cables clamped onto the battery terminals. This is an EXCELLENT unintentional safety feature.
Preset the voltage. Then connect to the battery. When battery charges and voltage rises to it's maximum, tweak the potentiometer up a tad.
A battery at near but not quite full charge can take nowhere near the full amperage potential of your Megawatt.
So when you do the final tweak, what you see on your meter will be the final voltage.
NOTE the difference between your first setting and exactly how much more you need to tweak the pot to get final desired voltage
EXAMPLE
Set voltage to 14.7 but final voltage when connected reads 14.48. This is easy to tell because amperage has drooped low. Say to 10 amps. But voltage reads 14.48.
You need to tweak the pot to gain .22 volts to get 14.70 volts, right?
Well guess what? Do not set voltage to 14.70 volts before connecting the cables to the battery.
Set the voltage 14.70 + .22 volts. Your meter will read 14.92 volts. THEN connect cables to the battery.
This disconnected - vs connected voltage difference is referred to as SLUMP.
Try it. It works like a charm. I can see absolutely nothing you are doing wrong or are missing here. You are doing a good job.
It's time to stop walking on eggshells. In the short time it takes to stand on the handlebars you will end up laughing.
You are missing a power timer on-off switch for the AC electricity. Look at an INTERMATIC 4-hour timer of eBay. I will walk you through how to connect it. This turns the Megawatt into a purring kitty.
