Haven't had the boat out in about 6 weeks. Weather and shoulder issues. Getting ready to go tomorrow morning, hooked up the MK 440Pc charger for a couple of hours. New(ish) lithiums for the trollinlg motorcharged right up. Sams club Group 31 agm starting battery/electronics not moving the meter...led's. But it will turn on the electronics and when I turn on the key (not starting, just turning on) I can hear the fuel pump fire up. Battery is 2021 but not a lot of hours on it. If it doesn't charge, well ok, new battery time. If it charges and won't turn over? 2018 Basscat Eyra, 250 merc 2 stroke. Never had issues and never had to look. Is there a fuse under the console going to the actual starter or is it a direct line?

Do you have to unplug when you store it?

I don't understand the problem.
Is it just not charging after sitting for 6 weeks? Have you checked the battery voltage?

If the battery is dead and its been sitting you may have damaged the battery. The only way to tell is charge it and see how it does.
If dead, you can parallel a charged battery to the starter battery for 15 minutes. Or hook jumper cables from the car battery. That will charge the starter battery enough that the charger will start working.

Most chargers require the battery to have at least 8-10vdc before it will charge. If battery voltage is too low it will signal to not charge. Check voltage and if too low use jumper cables from one of the other batteries to get the voltage up enough for the charger to kick in. After fully charged let it rest over night then check voltage.

Did you turn the disconnect off before you stored it 6 weeks ago? And like tmd11111 said

Take a meter and measure the agm battery voltage when it is not being charged. You can look up voltages online if what it should be. To verify the charger is working plug in the charger, and measure the battery terminals again as it's being charged. It should be much higher (say 13.x volts dc). If the voltage when charging is the same as the first measurement (not being charged), check to see if your leads that go from the charger to the battery have any inline fuses. I have blown a few of these on two different chargers. But you should have a good idea what's going on after this. Lastly, do you have a main disconnect from this battery and all the electronics? Even if your electronics are off, they have a very small current pull (milli amps). If you don't have a main disconnect, you need to put one in line. If your charger is a 10 amp charger per bank. It will take 10 hours to charge a battery (agm) that is fully discharged. Good luck and keep us posted.

Thanks Brent. Yes, have two disconnects on the boat. One for tm batteries and one for starting battery/electronics battery. Charged overnight and it was not coming up. The only thing that originally surprised me was the graphs/console/lights would turn on but the motor would not even try to turn over. Charged it up overnight...dead. Headed back to Sams for a new one. 4 years on it this month, so not that bad. Thanks boys!

Try putting a manual charger on it.

Did you check the charger bank?

I replaced a Blue Top several years ago only to realize I had a bad bank on my charger.

Checked my 4 blue tops last week and I still have 2 going strong that were manufactured in 2014. Could very easily still have 3 if I would have checked my charger first.

A volt meter will answer your questions.