Using the cigarette lighter DC out as a temporary battery tender

I tried to test Using the cigarette lighter DC out as a temporary battery tender for my 12v/100ah dry cell camper battery. This is something I may need on a couple of long ultra running weekends a year.
When I tried this, using an existing battery tender line I got no indication that there was any draw from the AC50S (like I do when I hook it to a running 12v fridge) or any improvement in the dry cell’s power.
*AGAIN, I don’t need to do this very often but it would really help if I could integrate the AC50S on occasion, especially because my wee 120 of solar will be feeding into the Bluetti.

I just watched a YouTube video regarding the “no display” scenario. Looks like if the accessory you are using is not pulling a high enough Wattage, the display doesn’t show anything. Test again, but with a multi-meter at the end of the battery tender to see if your Bluetti is putting out anything.

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@phoenixrising yea and to add to what @yonpds mentioned, it wouldn’t hurt to invest in a kill-a-watt meter to have on hand for times like this too. Has come in handy for me a lot! :metal:

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I’ll check that out. Thanks!

Oddly the pictured connection worked. As soon as I connected to it the Bluetti was integrated with the camper battery system. I don’t know and can’t find out (without tearing things apart) what’s different about it than the tender connection I used.

If your dry cell camper battery voltage was higher than the Bluetti DC output, you would also see no wattage drain displayed. Basically if your camper battery was already sufficiently charged there would be little to no wattage drain.

Makes perfect sense. I did test it with the house battery down.