Elite 9 TI2 touchscreen

Trying to rig it up for ice fishing and finding the touchscreen doesn’t want to work.
Bought a new Lowrance Power only cable, hooked it up to a 9ah battery, the unit powers on, but touchscreen doesn’t work. Thought maybe the unit froze, so I hooked it back up to the boat (Power cord only…no transducer) and the unit works fine.

Checked voltage of the ice pack battery, and under load, reading 12.25V. Shouldn’t be a voltage problem. Only differnce I can see is the cable itself. The one in the boat has many more leads, but I’m only using the power + and -.

Could this somehow affect the unit’s operation?

It’s likely a grounding issue. I’ve had it happen to various degrees when using a portable battery pack.

Try operating the touch screen using your 9AH battery while you’re touching the negative terminal with the other hand.

Waxy

Grounding is definitely the issue for a touchscreen. I think you are going to find issues using it on a portable situation for any “only” touch screen unit. I know its been discussed here and elsewhere before, but I cannot recall how others were able to or if they even were able to resolve.

This vid may be of help. There are others I just searching for Lowrance GPS Touchscreen grounding issue:

Did you actually try it on the ice. I had an HDS 9 that I was setting up to use on the ice and using it in the house I could not get it to work. Worked fine on the boat.

Found some info that it has to do with grounding. If you try it in the house put one finger on the negative terminal of the battery and then see if the touch screen works.

I pulled my hair out trying to figure this out.

Thanks,

RVRDUX