Best Practice Lithium Charging

[PMantle]

The precision is not rated for lithium per the website, I checked it out. There is no setting for lithium and they do not support lithium from what could find. Where did you get your info?

The quote below is straight from the Minn Kota site, but beware, at least two vendors here say Precision is fine, but digital, no:

Can I charge Lithium based 12V batteries with my Minn Kota Precision or Digital charger?

Yes, Lithium based batteries can be used with Minn Kota Precision and Digital chargers. Before using any charger on a Lithium battery, check the battery manufactures charging requirements to ensure a proper charge. In most cases, the manufacturer will suggest using the AGM setting for Minn Kota Precision chargers.

[scubatelco]

Yeah I did find that too. These lithium batteries require a higher voltage and have a BMS (battery management system) that protects the cells from all kinds of issues. For the price of these batteries, I would prefer a smart charger with a lithium charge profile that was designed specifically for lithium cells.

[PMantle]

Yeah I did find that too. These lithium batteries require a higher voltage and have a BMS (battery management system) that protects the cells from all kinds of issues. For the price of these batteries, I would prefer a smart charger with a lithium charge profile that was designed specifically for lithium cells.

Well, the sponsors here selling lithium say precision is fine.

[bobcoy]

SOC is certainly an issue if they’re dead and I am trying to fish!!!

I do understand what you are saying though, that it’s not to the SOC that is harmful to the battery, it’s the overpresence of the charger.

If the charger is compatable with the battery mfr it should not cause any issues if it is working properly. We were talking best practices. I have had a major issue in the past (lead acid)leaving the charger plugged in so I try hard not to have the charger plugged into AC overnight or longer. Just my choice if at all possible. SOC on Lithium batteries should normally be kept between 20% and fully charged for the best possible lifetime. Lower is not an issue to worry about. BMS keeps it safe from damage. Bob

[fishin couillon]

Going to throw another angle on this. If a guy has lithium TM batteries and an AGM for the big motor/electronics would he be better off with a separate charger for the AGM and leave it plugged in?

I have this setup......currently i have a 3 bank Dual Pro, disconnected the two leads for the Li tm batteries and just left if for the AGM. Done it as i did every other time, plug it up after a day of fishing. As for the Li trollers, i have a single 10amp charger, just make sure i charge them a few days before going back out or when needed. Now, i just bought the a Li cranking battery so, i plan on getting the new Noco 3 bank charger that has the Li profile to charge all 3 Li batteries.

[scubatelco]

I just got a reply back from noco support. Their lithium mode disconnects the charger after the battery reaches 14.6 volts and then monitors the battery. This is what I was looking for from the Minnkota charger but I don't think it has that feature.
I am buying the NOCO GeniusPro 10x3.

[jtracc]

The precision is not rated for lithium per the website, I checked it out. There is no setting for lithium and they do not support lithium from what could find. Where did you get your info? I did find they are using the AGM setting to fudge a lithium battery setting. I don't think that is the same 14.6 volts the lithium needs to fully charge.

The minn kota pc charger is what was recommended by milltech for their lithium’s and charges my batteries to 100% every time so...

[catdude28]

If you have an AGM crank battery and lithiums for the troller with a MK PC charger, you could change the ring terminals on the two deep cycle leads to quality quick disconnects with the other ends permanently attached to the battery. That way you could leave the charger on constantly for the AGM with the lithiums disconnected, and simply plug in the quick disconnects when the lithiums need some charging. Totally safe as MK specifies that unused banks can be disconnected while charging as each bank is really an independent charger on the PC chargers. No need to buy another charger.

[PMantle]

Great plan. Do you recommend any particular parts?

[scubatelco]

I double checked and Minnkota chargers are not compatible for lithium batteries. If they don’t have a lithium battery mode they will continue to charge the battery and rely on the BMS to stop the overcharge. I am looking for a true lithium 3 bank onboard charger. So far I have found the noco geniuspro

[catdude28]

I double checked and Minnkota chargers are not compatible for lithium batteries. If they don’t have a lithium battery mode they will continue to charge the battery and rely on the BMS to stop the overcharge. I am looking for a true lithium 3 bank onboard charger. So far I have found the noco geniuspro

The MK PC chargers in AGM mode only reach a maximum of 14.4 volts in aborption phase. In spite of this, many are using them and getting their lithiums to full charge. Obviously a lithium charger is still optimum.


Table2

CHARGING PROFILE @ 25° C
Battery Type	Absorption	Equalize	Float
Flooded Lead-Acid	14.4V	15.5V	13.2V
AGM/High Performance AGM (Absorbed Glass Mat)	14.4V	n/a	13.4V
Gel	13.9V	n/a	13.4V

[DavidAnderson]

I just purchased 4 Ionic Lithium's and have relied on Andy at Drewtech for information regarding the charging and care of these batteries. There is a very long thread, maybe 89+ pages that pretty much explains everything. The answers I received were enough to make me replace all the batteries in my boat. I cannot speak for any other battery than Ionic Brand however yes a Minnkota digital or Precision charger will do an excellent job charging in their AGM mode, at least that is what I was told and is how I am handling the onboard charging. The Battery's BMS pretty much does all the thinking. I was told that it is OK to leave the battery charger plugged in as the BMS takes care of any issues. I received my batteries last Monday and was anxious to install them. The Ionic's have a Bluetooth connect to their phone app and it gives an excellent status of the battery. They have been plugged in since Monday and all batteries are fully charged and the app states they are in Standby mode, 0 current, 13.9 to 14 volts. As my AGM's used to see, I will probably keep mine plugged in 100% of the time while parked as I like to be fully charged when I go. As well, Lithium's will last longer if you charge them each time you are done as they don't have a memory.

[bobcoy]

Your battery specs should specify a recommended charge voltage. 18650 cells(cylindrical) are the most common LiFeP04 in marine batteries. for 12 volt batteries 14.2 to 14.6 volts are recommended. The prismatic(pouch) may have slightly different voltage. None of them want or need a float voltage. but can tolerate up to 13.6 without damage. Like I said, use your batteries mfr recommendations. Bob

[jtracc]

I double checked and Minnkota chargers are not compatible for lithium batteries. If they don’t have a lithium battery mode they will continue to charge the battery and rely on the BMS to stop the overcharge. I am looking for a true lithium 3 bank onboard charger. So far I have found the noco geniuspro

100% not true ... many lithium manufacturers recommend minn kota PC charger in AGM setting. Like I said in previous post charges my lithium’s to 100p every time AND it was recommended by the manufacturer so....

[sktrbtr]

https://ampedoutdoors.com/collection...harger-lifepo4

This is what I have with an extra harness for 2nd battery. There are disconnects to plug into whichever battery to charge. Not for lead acid batteries though.

[Smalliefan2]

I am switching to lithium, Relion. Called Dual Pro, which I have now for my lead acid, AGM. Inquired about charging lithium's. They suggest a charger with the specific manufacture charging profile, which they custom manufacture. Ordered a two bank for the lithium's, and a Minn Kota PC 110 for my AGM. Don't like the idea of two chargers, but I did not find any that did both types off a three bank charger. Talked to Minn Kota, and Relion in my research and both agree the Precision charger would work on both types of batteries, just the lithiums would charge about 95% max with the Minn Kota on the AGM setting.

[bobcoy]

I am sure you have a great setup. Just wanted to mention 95% is not a bad thing unless you have your batteries sized to a bare minimum. Bob

[rfdong]

yes I figured this out quickly... I went with smaller lithium’s 65ah thinking I will have to charge every trip so I picked up minn kota pc 3 bank to go with it. I can’t kill the 65ah in one day (I tried) I can get 2 solid days plus. I don’t charge the lithium batteries every trip but need to charge my AGM cranking battery, so I picked up a small portable smart charger from Canadian Tire that has leads That permanently connect to the battery. So AGM gets plugged in soon as get off the water and home, the lithium’s only get a charge the night before. I don’t forget.... so far so good with this set up.

you can take the fuse out of the bank(s) you don’t need on the MK PC chargers

[PMantle]

I double checked and Minnkota chargers are not compatible for lithium batteries.

Stop posting misinformation. It's one thing for you to not prefer that charger, but it's another to post something patently false.

[jtracc]

you can take the fuse out of the bank(s) you don’t need on the MK PC chargers

Yes you can, however, over time I would think you would get wear and tear. I find the small partable charger works great, it wasn't too expensive and I can you it for other batteries round the house if needed.

And yes the minn kota pc charger works with my lithiums, in fact it was recommended by the manufacturer.