Another Lowrance H2O problem

I have an H2O huntC that I love.
Unfortunately, I have experienced the same problem with the 12V cigarette adapter power cord, that has been lamented here several times in the past. I have had to hold it, wiggle it or put a binder clip on it to keep it working…
My 12V power cord finally stopped working at all, and to get by until a new purchase is made, I have been running on battery power.
I use my H2O HuntC in my truck for work and typically turn it on for 20 minutes, as needed, and then turn it off to save battery power.
The last four times that i have replaced batteries, I used the unit for 10-20 minutes and then shut it off.
The next time that I tried to turn it on again, it is completely dead, no battery power at all
Just for final confirmation, yesterday I needed the unit to find a destination, in the morngin. I loaded a couple of brand new Energizer Maxs into the unit. It turned on and performed perfectly. After about 15 minutes of use, I turned the unit off and left it alone for about four hours.
Later yesterday, I tried to turn it back on and once again, the batteries are completely dead.
I even tested the batteries and they are down around .4 volts, dead!
Any ideas what is happening?
I realize that the unit will likely have to go back to Lowrance, but I hate to be on the road without it.
cheers

I had the same thing happen with my expedition C+ and what I found was I was only turning off the back light and the unit was still on now I make sure its off and have not had a problem

I also have 2 sets of Energizer rechargeable batteries and they have worked well for me.

You may have it in standby mode, you need to put it in powerdown mode

Sadly the best unit available has issues. I’ve come to reason with myself that these units are are disposable. I’ve gone through 4 H20’s and 5 power cords but then thats over 6 or 7 years. Me personally,…..I’d either buy a new one or switch to Garmin before I’d deal with Customer service and shipping it. Now that I’ve heard myself say it,…I may take a closer look at other units. I’ll be quite honest and straight forward,….The Lowrance H20 has a great user interface and excellent features but it is a unit that should viewed as disposable. I gave lowrance 5 plus years to figure it out,……Nothing has changed