Battle Born Charging

Why be confused? Just follow the manufacturer instructions.

No need to figure out every possible lithium battery, just follow what is needed for what you have.

If you wanted and could shut of the absorb stage and go straight to a float, you certainly could.

Float is a term that gets confusing with lfp. Float as most know put your wets/ agm on it after taking it home, put it on the charger let sit there till the next time needed whether next weekend, next month or next year.


With solar you can "float" lfp. When it comes to day to day usage, its a different story. The goal here is to set your solar controllers float voltage so they cover the loads, but are putting in essentially zero amps. So at least you are not throwing away your excess solar. You will often hear people say you need to charge to full and then turn off your charge sources. When really you need to charge to full and STOP (no amps going in). Turning off your solar at 2pm would be wasteful as you would be throwing away tons of power and using batteries unnecessarily.

Well, I find it all very confusing, so it is a good thing I don't have an Li-ion battery.

Your post showed amps tapering from about 85%. That would normally indicate you are in the absorption stage. Yet we are being told that does not happen so soon with Li batts. Where does that 20-30 minutes come in?

With Wets and AGMs it happens that the higher the charging rate (amps wrt to battery AH), the lower the SOC when Vabs is reached and Absorption begins with its tapering amps. It should be the same with Li batts, but perhaps with a higher set of SOCs.

The charging profile graph in the batt uni link should have helped but does it?

BB seems to want you to limit the charging rate to about a 50% charging rate. Typical wet 6s can do about 33% without difficulty. Ordinary AGMs spec limit is about 27-30% but Lifeline AGM allows huge amps in Bulk. If you do the huge amps, expect a low SOC for when amps start to taper.

The BB replies to questions in their link seem somewhat inconsistent or contradictory wrt "floating" at 13.6 and when is "full".

It would be more use if more people with knowledge of all this would post their experiences in managing their Li batts. I find it all bewildering, but I don't have to actually figure it out except from curiosity.

With what those things cost, I would want to know exactly how to manage them if I got any!

BFL13 wrote:

Itinerant1 wrote:
I'm at my 99% SOC when it hits absorb.

I presume you know when that is by observing that amps start to taper.
Why do 10 minutes more? 99 is way over 80.
What is the truth about operating under 80%?
Can you do the 20-30 min BB wants past that 99% without overcharging?

What is the "marker" for true full with Li? ( With Wets it is the full SG. With AGMs it is when amps taper to 0.5a/100AH at 14.4v during Absorb.)

When I first started what Iternerant1 said is what I was told too , that's why I used the battery charger that i did , because I was told Li likes to be charged at alot of amps pretty much all of the way to 80%.

Bulk Absorption all of the way to 80% , you don't need the charger to drop down from your set voltage , pretty much 14.4 volts the whole time , no need tor a multi stage smart charger.

If you don't plan to use the battery and your going to store it you keep it around 40 thru 50 % soc would be ideal.

The term float voltage confuses me because I was told you don't float but you take the battery to fully charged, charging at 14.4 volt the whole time until you get there.
Keep in mind I charge with a 2000 watt genset, a 60 amp charger that is fixed voltage of 14.4 volts .
I think when there refering to a float voltage of 13.6 volts I'm thinking there using solar panels and so it drops down to 13.6volt and charges from the sun all day ,
I don't know for sure Itinerant1 could probably tell us.

Doing it my way the Li benefits me because they charge fast , I can get them really high soc quickly and so I don't have to use
generator very long , that means I barely have to listen to it and less fuel usage..
Fuel usage is about 33 cents per hour at current gas station prices.
Run genset about a hour a day to charge.

I don't know much about solar and I don't want to know about it unless I end up buying a house where I could have a bunch of panels.
I heard the benefit you get from Li if your using solar panels is since Li doesn't get damages if you don't get them charged up , so let's say the clouds came out and you had no sun the batteries wouldn't get damaged sitting at 40% soc all the time .

@BFL
Regarding overcharging
My Resister 1 has been snipped.
14.4 volts all the time.
So you read that the Battery management system doesn't protect from over voltage , good to know , thanks.
I assumed that the BMS protected against overcharging but I wasn't sure , I thought that because it seems like the BMS protects from about everything else like cold temp shutdown , low voltage shutdown.

I've always shut the charger off when my monitor reads close to 80%

Yes you can overcharge!
1. by over-voltage
2. by leaving the 14.x on for too long after reaching "full".

The Battle Born advice in their link warns about overcharging most of all. They stress no equalizing higher voltages to be used, and to reduce to 13.6 (or lower) after getting the battery full.

I am still confused about what is meant by "full" now that
1. it has been shown there are different types of Li-ion batteries, each with its own set of voltage specs, and
2. there are different ways to make a battery bank with balancing and how to monitor each type of bank. (or something like that!) where different rules for "full" may apply.

It can turn on when to make your monitor automatically reset to zero AH. ( I have my Trimetric's auto reset turned off. Bogart advises that if you have solar, so it does not reset every time it gets dark out.)

I suppose you can set your monitor to reset to zero AH when the battery is at something less than 100%, don't know. Just define "full" differently?

The problem is to know in the first place when it is really at any SOC, before you start making adjustments to your settings. It is so nice to have SG with Wets to use as your independent marker that always tells the truth.

Off topic--Be sure your locked in 14.4 setting does not turn into 13.4 after 15 minutes.

The PowerMax with the knob on top--some (not all models) have the 15 minute thing where it runs at a set voltage after being plugged in for the first 15 minutes, then drops one volt and stays there until adjusted again.

That is at the request of their main customer for those things (car showrooms). You can snip R1 (higher up off the board) and it won't do that anymore. It will then stay at the voltage you set the first time, but with a reduced higher limit of about 15.5.

BFL13 wrote:
I don't understand which model of converter you have. The older adjustables had the pot operated by a knob on the top of the case, but the latest version has the pot inside that you have to get at with a small screwdriver through a hole in the side of the case.

I have both , Powermax company gave me one for free because I sent one back that had problems.
The one I'm currently using is a 60 amp model that had the big potentiometer outside the case but I relocated it to inside the case after I got rid of the lead acids.

Itinerant1 wrote:

BFL13 wrote:
You might wish to modify your routine based on this advice. It could be that your 99% is not correct. Your displays might not be showing the true picture based on the graphs etc here. You might be overcharging somewhat?

At last some graphs and a way to tell when your Li batt is full!

" Full charge is reached when the current decreases to between 3 and 5 percent of the Ah rating"

https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

I'm sure you mean well but I'll stick to my routine/ settings.

Stick to what you know best. ;)

So on my 100ah battery , does it mean my battery is full when the
Amps drop down to 4 amps ????
If so I could use this info to verify my battery capacity monitor is set up correctly.
It may be off by 20% meaning every time I think I'm reaching 100% I'm
actually only at 80%.

I started charging at 11:55pm ,
My battery capacity monitor soc read 77%

Went something like this




So I would normally shut my charger off when it first reached
100% , which would be 12:27 Am this time but after reading your
post I watched the amp meter until the amps reached 4 amps.
When I reached the 4 amps that must've been the 100% soc point.
I probably need to set up my battery capacity monitor better.
Thanks BFL

BFL13 wrote:
You might wish to modify your routine based on this advice. It could be that your 99% is not correct. Your displays might not be showing the true picture based on the graphs etc here. You might be overcharging somewhat?

At last some graphs and a way to tell when your Li batt is full!

" Full charge is reached when the current decreases to between 3 and 5 percent of the Ah rating"

https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

I don't think you can overcharge, I believe the Battery management system (BMS) protects from over charging, I'm not sure about that though.
I know the BMS protects from voltage getting to low and also protects from low temp .

@Landyacht318
Alternator failure ,,
I saw a guy that had his alternator fail out in the middle of nowhere,
He ran his van electronics using his generator until he made it all the way to a town , i thought that was interesting.

I don't understand which model of converter you have. The older adjustables had the pot operated by a knob on the top of the case, but the latest version has the pot inside that you have to get at with a small screwdriver through a hole in the side of the case.