thinking I may have some elec drain on batteries been on lake twice, ran 24v. trolling motor maybe 1.5hr total, one batt shows 3.2v. other two were around 7.6v crank batt interstate new mid feb other two new 6/1. thinking of installing cut switch, switches. Any help or info Greatly appreciated.

you can buy brand new to you bad batteries. sounds like something left on or not fully charged before you hit lake.

Id start with checking out your charger. If you had a drain I would expect your starting battery to have less voltage but not all three batteries. Your batteries should never drop that low.

Thanks Javelin,not sure how to check on board charge, when plugged in 2 blue lights flash, on says power, other charging, would I put meter where charger connects at battery terminal?

i would start by disconnecting all 3 batteries from the onboard charger, slow charge each battery to peak on a 2 amp charger, let them cool for 24 hrs and recheck voltage, if the batteries show good and you didn't leave anything on, i would suspect the onboard charger has gone bad

You could put a volt meter on each individual battery while they are charging. You should see the voltage level increase during the charging phase. Sometimes if a battery is severely discharged the onboard charger wont recognize the battery and you will need to use a higher amp charger to get the voltage level up. If the batteries are taking a charge let the batteries charge overnight and then unplug the charger. Allow the batteries to rest for 24 hours and then recheck the voltage.

If those voltages are truly that low they may not be able to get fully charged again. Seems like anything below about 11.9V for cranking and 11.3V for trolling is considered dead. A full charge should be around 12.7-13.5V. It varies for different batteries and chargers some.