What batteries are you using and do you like them?

Background: The lead acid batteries that came with my used boat wouldn't hold a charge so I replaced them with a pair of 100 Ah LiFePO4 batteries. One is from Ampere Time and the other is from Li Time, which as far as I can tell is the same company.

They worked great for a year but now the Ampere Time is malfunctioning. My NOCO charger starts to charge it, but after a minute, it goes dark as if it isn't even connected to a battery. Then it goes back to charging for another minute. Back and forth. Eventually it shows a full charge. The NOCO charges the other battery steadily with no disruption.

Switching batteries to the other NOCO circuit shows the problem is in the battery, not the charger.

With the batteries wired in series, I get 24 volts to power the Minn Kota and it works fine for a few hours. But then the Minn Kota dies and won't come back on until I recharge. When the batteries were new, they ran the Minn Kota for 12+ hours. Judging by the charging time of the good one - the Li Time - I think the bad one - Ampere Time - is just shutting off before it is depleted.

The older of the two batteries is less than 3 years old with maybe 50 charges in its life. Still supposed to be covered by the warranty. Emails to Ampere Time Support have gone unanswered so it looks like the warranty will not be honored. So I'm looking for a better brand and will appreciate your input.