One can plumb the Megawatt right to the jumper cables cut in half, or anywhere along their length. Shorter is better from a voltage drop perspective.
One could plumb the watt meter inline between jumper cables and megawatt
One could put a connector, like Anderson Power Poles between the wattmeter and jumper cables.
One can do all three.
I rewired my wattmeter with 8awg and use 45 amp powerpoles on the 'LOAD' side of the watt meter.
I have a second 'portable' wattmeter with 45 amp powerpoles on both source and load I employ elsewhere, or here if that tickles my fancy.
I put 45 amp powerpoles on the my old schumacher alligator clamp leads, whose copper wiring I replaced with 8awg.
For the AC cord, if not provided, I cut off a 12awg 3 prong cord from an older unused Power strip.
This is a Meanwell, not a Megawatt, and the extra fans and heatsinks are optional:
Mine can hold 40 amps all day long, and the 12awg aluminum wiring that comes with the wattmeter got too hot for my liking, which is why I soldered 8awg to it instead and added the fans and heatsinks.
45 amp powerpoles are widely employed in my Vehicle. They require some skill to crimp properly to 8awg without their special 40$ crimper, but their 30 amps ones are simple to crimp with any dimple crimper, to 12awg. 10awg perhaps but some destranding might be necessary.
15/30/45 amp powerpoles will all mate with each other.
There is more than one way to skin a cat. This is my way and this cat's sulfation does not stand a chance.
There is voltage drop on the wiring between megawatt and battery terminals, and more so at higher amperage and more so with thinner longer wire.
The wattmeters become inaccurate under 1 amp of current.
If you are looking on how to hook wattmeter to jumper cables, a butt connector like this is simplest and can work OK, but will get hot passing 30 amps@12.2-14.8volts:
