Bad Batteries or Bad Charger or Both?

Minn Kota 65 lb thrust, 24volt (1- 1/2 years old)
New ProMariner ProSport 12, 12 amp, 2 bank charger.
Two lead acid batteries, Continental I believe is the brand, supposed to be new when I bought boat last year in August.

Batteries fully charged weekend ago, last two prior trips trolling motor worked great, went fishing this Sat. evening, noticed trolling motor was slower than usual, trolled and lost almost all juice (chasing noodles catfishing). Came home and 7:30 started charging, 18 hrs. later Sunday @ 2:00 fully charged, told wife lets go fishing, went to lake, got blown off lake from storm, use trolling motor maybe 50 yds., hooked back up charger @ 5:00 pm yesterday, still charging this morning.

I'm going to check voltage after they get fully charged, and daily this week.
Comments or help appreciated.
Thanks!

Have you checked the electrolyte level? Might look for a date code stamped into the top of the battery. 2 to 6 digit alphanumeric.

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Originally Posted by CatFan

Have you checked the electrolyte level? Might look for a date code stamped into the top of the battery. 2 to 6 digit alphanumeric.

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He means the "water" level. It must cover the plates, don't overfill. Your questions are difficult to answer without some voltage readings, but it sounds like the batteries are toast.
Read the voltage when being charged, and off the charger with the motor on high constant.

My plans for today after work...Checked charger at lunch, it showed it was full charge...Read a few threads here, 12.65 volts is the number I need to see.
Thanks!

Hot off the charger you should expect close if not over 13 until you hit them with a load.

Yes, that is correct...

Quote:

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Originally Posted by bulldog44

My plans for today after work...Checked charger at lunch, it showed it was full charge...Read a few threads here, 12.65 volts is the number I need to see.
Thanks!

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I can’t find any specs online about Continental batteries. No battery I’m aware of has a lower full charge voltage than 12.65V, but some flooded batteries are 12.7V, and some as high as 12.72V. Lower than 12.65V and you have a problem for sure. Otherwise you might contact them for advice.

Batteries...looks like I'm replacing two...
Thanks all for the replies...

Checked voltage today, 12.27 on one, 12.67 on the other (trolling motor batteries wired 24 v)
They were very low on water, added water, charged them yesterday.
Going to run them Sat. morning, and I expect to be buying new ones Sat. evening.
It's either Everstart from Walmart, or Duracell from Sam's...Help me decide!

Ran trolling motor over two hours, had it on constant, never stopped and still going strong. Checked gps speed at beginning, 3 mph on 5 setting (65 lb thrust), Checked after after two hours, still 3 mph. Batteries showed 12.23 & 12.59 volts when I got home.
This was after I had to add over a gallon of distilled water into both batteries. Plates were exposed when I added water.
Before I left, batteries showed 12.46, & 12.67 after adding water and charging. I'm pleased. Going to keep using them till they stop.

Old fashioned fix. Instant batteries, just add water.