After a day of Crappie fishing recently, on a DFW lake,I decided to take my catch call it quits. But I GOT A BIG SURPRISE when I turn my ignition key. The all too familiar Varooom that I had grown accustom to hearing was none existent & replaced by unthinkable clicks. After concluding that my batteries were dead ,I began to realize I had been on the water for over 8 hrs with my Electronics still going in normal mode however the Trolling motor still remained operational so..... This bring a Question to my mind since I`ve always launch with fully charged batteries and have never experienced this before.Is this a common problem if electronic are allowed to operate in normal mode for extended periods without using the standby mode?

Depends on the battery and the graph. I would say that most batteries running graphs would be weak after 8 hours. If your graph has the ability to display volts, just keep an eye on it and charge when it gets down to 11.5V. Just for reference, my group 31 battery runs my Onix and Grayline tank for 4 hours before it gets to 11.7 V.

And some motors are more volt/amp sensitive than others, a merc Pro XS requires more juice to start.

the motor is a 150hp merc blk max xr4

It`s a 24volt system running HDS12 Hds7 & Elite 7 HDI Graphs.Batteries are group 27

Pretty typical. Either start your motor a few times during the day and make a short drive or carry jumper cables.

A Weego is pretty damn handy to have around for times like this

I assume you have three total batteries - 1 for cranking and 2 for TM? The graphs can absolutely run down your starting or your TM battery during the course of the day. Most guys on here run them off the starting battery so it can be recharged when moving across the lake.

BINGO !!! Three batteries.

Thanks for all the comments Guys.

+++++10,000 x's on the WEEGO!!!! Best $100 investment I've made. I havent used it on my cranking battery in my boat yet, BUT, I HAVE come across TWO other disabled boaters that needed a "jump". No problem,lighter, smaller & much easier than jumper cables. Cranked em right up. Pretty sure both those boaters went & bought one afterwards. Charge it once a month.
Bought 3 more. One for my pickup, one for daughters vehicle & one for son in laws vehicle. They make GREAT Christmas,Birthday gifts for friends & family.

^^^^^^^^
WEEGO plus 1

Don't know if this post jinxed me but had the same surprise on Cedar Creek last night or morning 3 am and got lucky someone was working on a dock and let me plug the onboard charger in.

If you have room I usually just put in an extra battery just to run electronics off of

I have run 2 hds8's for years all day long on a group 31 and never have had a problem with a low battery after I replaced the wiring, I just replaced my 3 trolling motor batteries (group 31) a few months ago after YES 9 years per the tag on them and they were weak the new ones last 2 days with a 101 IPilot used all day, the installation was done on my boat with way to small of wire when we replaced it had never anything problems again, check your wire size. Everything now works better charges faster too.