Energized Outdoor 10a Lithium with Humminbird Helix 5 - battery percentage ?

[3whitevanes]

Hi all.  I have a Helix 5 mounted in the Humminbird ice pack, and I bought the 10ah Lithium battery to use with it.  It has lasted from dawn to dusk, even with the white background running.  My Helix display is showing the battery percentage still at 100% at the end of the fishing day, and I'm sure it isn't correct.  Anybody have any ideas why this percentage wouldn't be dropping throughout the day?  Previously, I had a non-lithium battery in use with it, and the percentage would gradually drop throughout the day.  Any help would be appreciated.  The unit is holding strong yet at the end of the day, so I have no complaints about it, but I'd like to know how much of the charge it actually uses during the day, so I can compare it against the non-lithium battery.

[Kevin23]

Lithium batteries hold their output voltage all the way until they die, then just die. That's why they are so good for tool batteries, no loss in power until the end. So your volt reading battery gauge will not work.

[3whitevanes]

I've heard something like what you mention.  So, is there any way to tell how much battery I have left at the end of a day of fishing?

[jchunter]

That's how they read with lithium batteries. The Helix was designed for a lead acid battery so the reading doesn't work. Since lithium batteries put out a constant voltage until they die, it doesn't show the drop. The lead acid batteries drop in voltage as it's being used, hence the drop on the indicator.

[RyanW]

You could always just let it run until it dies and note how long it takes. Then you’ll know how much battery is left after so many hours.

[Kevin23]

I've heard something like what you mention.  So, is there any way to tell how much battery I have left at the end of a day of fishing?

The discharge looks something like this. So even a discharged lithium is still at "full" 12v battery charge.

[icehound67]

Look at the voltage reading on your unit?

[3whitevanes]

You could always just let it run until it dies and note how long it takes. Then you’ll know how much battery is left after so many hours.

This might be my best bet.  Thanks for the suggestion.....I'll post my results after this coming weekend.

[BowHunter1527]

The only way to get an accurate read on the battery is to check its voltage.