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Fully charging 2 12v for 24v trolling motor

GetnThere

New Member
Joined
Apr 4, 2023
Messages
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Location
Nj
Hi All,
My 1st post & question.
Background
I have two new Chins 12v 100ah batteries no blue tooth and Victron IP22 20v 3 bank charger. I will also use a shunt when put in series to track usage and remaining capacity. Thus, best case would be to max the charge as they will be drawn down quite a bit and maybe completely.

Usage
The trolling motor will be used for both traveling, getting to the spot and fishing, moving around the area to fish as outboard is prohibited.

I charged the batteries by simply using the ion selection. The voltage is 13.4 & 13.6 per the meter, seems the batteries should go to 14.4 if I'm reading the provided material right. I understand lithium doesn't like to be a full charged for down time but how do I charge them to 14.4 the night before fishing, if I'm supposed to do that. Victron has an advanced mode but I didn't feel comfortable using that yet.

Victron doesn't show batteries separately so that's confusing. I also tried each one separately but the meter seems more accurate.

Thanks for any help let me know if more info is needed.
Ken
 
Are you certain the batteries did not go to 14.40 and then drop to float at 13.4/13.6?
OK to reconnect and charge again while the voltage is closely monitored. Yes I would verify both get to the same 14+ volts before placing in series.

As long as the batteries are both fully charged the meter can track one or both. The percentage charged or discharged will apply to both.
 
If I want to do this... I would charge each of the batteries separately... I would probably hit them at a constant voltage of around 14.2 or 14.4 with a power supply


I would do this until they have no amperage flowing... Then I would let them rest for maybe an hour and check the voltage...

All that being said my guess is that they're going to have a disconnect at around 3.4 or 3.45 per cell...
 
Thank your guys for your replies. First I charged them individually then connected both at same time with the "lithium setting". I'm not sure if they reached 14.4 then dropped down but i seriously doubt it. The Victron does have a "normal setting" that would bring the V to 14.4. The Victron IP22 3 bank, readings doesn't make sense to me so I'm using the meter too. They're in "storage stage". It makes sense that the BMS would cutoff charging to prevent overcharging. Instructions are not that great for my application. Any estimate on how long it would take to go from 13.5 to 14.4 for a single battery if I changed the setting? If I do that should I add the shunt to track it better? Thanks again for your help
 
According to Current Connected (active on this forum and reliable source for products), they say this:

Victron’s Li-Ion profile is NOT sufficient for non-Victron LiFePO4 batteries. They have instructions on how to program the IP22 to properly charge a non-Victron LiFePO4 battery. (You might have to click on the "Lifepo4 Settings" tab if it doesn't automatically take you there.
 
Tomthumb62,
Thanks for the link I'll have to adjust my settings.

Time2roll,
The batteries might have reached 14.4. Vic graph is fixed and it just shows the battery going through it. It does have a peak point that's very short duration then drops off to storage like you mentioned. I didn't know the V could drop without some kind of usage. I'll try adjusting my settings tonight.

Thanks again
 
Yes the Vic should have gone to 14.4 The real issue to verify is that the Chins went to 14.4 without an internal disconnect due to some error.
 
I didn't know the V could drop without some kind of usage.
That is why it’s hard to say what really happened without some kind of tracking data or you having witnessed the whole thing. The cells have to be fed something sufficiently higher than their resting voltage in order to push current into them, but when charging ceases the voltage will eventually drop to ‘actual battery voltage’ aka resting voltage, and13.4-13.6 is a normal range for a ‘fully charged’ lifepo4 ‘12v’ batt. I would just want them to both show the same thing!
 
Delay because work got in the way again but I reset according to the settings from current connect. I didn't see much if any difference. The resting current seems to be at 13.5 for one and 13.35 for the other. I hooked up a shunt, series connected the batteries to 24V ran the trolling motor, it worked. The shunt said current A draw was 1.65, the motor manufacturer said the max draw would be 34As. Not to sure what 1.65 is? It listed v at 26.8 that made sense, energy usage didn't register because I only ran it for a couple of minutes, testing each motor setting, all showed as 1.65, odd, same A draw at low to high settings.
So,
What does shunt current A 1.65 mean?

Is there a way to track the battery/ies V over charging cycle and when used or is what Bluetooth batteries do?

Should I discharge the batteries some as I wasn't able to use them this weekend and if so what's a good resting V?


I thought the Vic would track "actual" V in charge cycle vs just showing what "should" have happened. It doesn't show the two batteries separately either and i thought i paid more for the better charger. Or it's just my learning curve.
Thanks
 
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After I used the batteries for two outings back toback days, they performed well. I didn't run them to zero but after a long day of fishing they held the charge well. The Vic charger on loin then I used regular to top off the battery,14.4V, the day before for an hour or two, I disconnected after. It didn't get to 14.4 that I know of. After a day of fishing the V dropped to only 26.2. I noticed my shunt had remainng V that would be lower when running but higher when not used. So it didn't get close to 24.0. Seems like I had a lot of power remaining. I charged them in parallel, as they're light enough to move in n out of the storage box. Any other opinions on the data?
 
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