Trolling motor/Lithium battery question

[Tarheel14]

I have a MK Maxxum 80lb TM. According to what Ive seen the max AH draw is 60AH. Is this correct? My 3rd trip out today using these batteries. Ive had no issues until today. I fully charged them last night. They do not have Bluetooth monitoring so I do not know the exact voltage they were this morning. I have a Noco Genius 5x3, Yes I know it should be at least 10amps per bank not 5amps. I did not know this until after purchasing the charger.
Used the TM most of the day today no issues and and was trolling on about 60 out of 100 on the dial. The TM just quit. Batteries didnt slowly die. It just all of a sudden did not have any power. I waited a few minutes to see if it was something in the TM that shut down temporarily. I checked all the circuit breakers and all was fine. It just didnt have any power. So I loaded up and came home. The TM is now working. My batteries checked 12.0 Volts on one and 13.2 volts on the other. They are wired in Series and I have 24.9 Volts between both batteries.
Is it just because these batteries are 50 AH batteries and I should have at least 60Ah batteries? I emailed the company to find out my options.
Does any company take lithium batteries on trade?

https://www.redodopower.com/products...ery-640wh-640w

[Bass in the grass]

I’d check the charger, because one of your batteries is dead and the other isn’t. Without BT, hard to tell anything about the battery. It might be good or it might be junk. First place to look is the charger though.

[Tarheel14]

My charger shows the batteries were all "green" this morning. Looks like it is charging just fine.

[DREWTICK]

Chargers can fool you with lithium, they can turn green and cut off and battery still be at 80% charged, the lower amp NOCOs are known for that, running it on the AGM setting will help

and yes 50ah on a 24v trolling motor can be great for some and no where close to enough for another depending on how you fish

get a good voltage reading on them after they are topped off

[Tarheel14]

Chargers can fool you with lithium, they can turn green and cut off and battery still be at 80% charged, the lower amp NOCOs are known for that, running it on the AGM setting will help

and yes 50ah on a 24v trolling motor can be great for some and no where close to enough for another depending on how you fish

get a good voltage reading on them after they are topped off

They are currently charging. I will check them with my voltage meter after they finish charging. I also emailed Redodo to ask what my options are? I should really get some bluetooth batteries or at least by a blue tooth monitor for them.

[Bass in the grass]

They need to be 13.6v when fully charged, if they aren’t getting there, then you need a better charger.

[Tarheel14]

They need to be 13.6v when fully charged, if they aren’t getting there, then you need a better charger.

Thanks for this information. I probably do need a better charger.

[RickCamilleri]

Soinds like something got hot and it shut itself off as a precaution. The mk website has max amp draws for 80# listed at 56A. You wore might be too small for the length of run

[rid 05 198]

So you were running at 60% most of the day? Sounds like they should be down.

[goodman_fishing]

My batteries checked 12.0 Volts on one and 13.2 volts on the other.

That's a red flag there. Something is up. That 12.0v battery is basically dead at that point and they should be closer.

[Tarheel14]

I was running at around 30 most of the day. It just happened to be at around 60 that I was running and the TM quit working.

Yes, our 12V50Ah batteries cannot be used to power a 24V 80lbs trolling motor as the max. current of the trolling motor is 60A.
Now can the two batteires be charged/discharge normally?

This is the response I got back from the Redodo company. I do not understand what it means? I emailed them back to clarify.

Today after the charger charged them all night. 1 battery is reading 11.9 volts and the other battery is reading 13.8 volts. I did let the company know that. I hope that they can warranty it or tell me what to do. I asked them about charging the batteries with a charger that only puts out 5 amps per bank.
Im kinda in a pickle. I need to sell that charger and buy a charger that puts out 10 amps per bank. But who is gonna buy a charger that only puts out 5 amps per bank? I guess Ill list it on here an see if anyone is interested. Im a little frustrated and at a point I dont know what my next move is. I guess its to sell that charger and get another charger and see if that will charge those batteries better.

[Tarheel14]

NOCO Genius GENPRO10X3, 3-Bank, 30A (10A/Bank) Smart Marine Battery Charger, 12V Waterproof Onboard Boat Charger, Battery Maintainer and Desulfator for AGM, Lithium (LiFePO4) and Deep-Cycle Batteries

Is this a good charger? Is this enough power for lithium batteries? I know some of the batteries recommend more than 10 amps per bank?

[musky/ed]

You could try swapping the charging wires and if the other battery charges up, then you know its the charger and not the battery, if the dead battery is still dead, it's the battery

[NoCAL]

You need to:
1. take them out of the boat
2. charge them fully to 13.6 or better
3. buy a cheap inverter, hook up a light bulb and test the AH of each one when fully charged ( you'll have to figure out how much the bulb draws for how long the battery should power it)
4. if both batteries power the bulb for the appropriate amount of time, recharge them separately again
5. balance the batteries (plus to plus, minus to minus for 24 hours)
6. install with your newly purchased BT SOC shunt (I have the one from Amped Outdoors)
I've run 3 Redodo (Zooms) batteries for almost 3 years and have had to do this once because a blown fuse in the charger. What you describe is exactly how LiFePO4 batteries work. It ran perfectly up until the point that one battery died. I think you have a charger issue most likely. If after you have done the above and there is still a problem, write back to Redodo, tell them what you did and they will warranty the bad battery. You have a 5 year warranty. That charger will work great.

[Bass in the grass]

Definitely swap the charging leads and verify the charger hasn’t lost a bank.

[Tarheel14]

Thanks. I did the balance the battery charging them separately when I first got them a few months ago. I will definitely try to figure it out

[JK9027]

Your meter will show charger coming on and off. I've been told that 10% of ah rating is enough charger so for 50ah batteries you should be good. Interested in what you find out.

[Tarheel14]

I used the "repair" mode on the NOCO charger. I just put it into the regular charge mode now. It still reads 11.9V but Ill see if it charges up anymore. The company told me to disconnect the battery completely wait 30 minutes and see what the charge is. Ill keep yall updated.

Thanks for the help....REallyy appreciate IT.

[JohnnyO]

On another note. I have a 24V MK Fortrex trolling motor. Does anyone know if I can use a Lithium 12v 50ah battery and a 12v 100ah battery connected in series. And if so what type of charger.

[bobcoy]

I would think “REPAIR” mode is a problem! Usually it is only something used on lead acid batteries. (15+ volts!) Drew can address that particular charger as I am not a user of Noco.