LFP and Alternator settings

[CaptainRivet]

Originally Posted by wholybee

This does not work. You CANNOT balance cells at 80% or 60%. It has nothing to do with the voltage setting in the BMS. Cells can ONLY be balanced at the "top" (fully charged) or "bottom" (fully discharged). If you attempt to balance somewhere in between, some current might move around, but you are not balancing the cells. It simply will not work.

The "best practice" as hard as it is to imaging, is to not worry about it. Go with the recommended settings. And this is important. By not worrying, I mean don't try and charge them to full everyday. PSOC doesn't matter so just let them be. Don't fixate on your SOC meter. Some days they will get to full, and some days they won't. You (mostly) don't care. If they get to 100% sometimes, that lets them balance, and won't hurt them.

If you find that they are getting to 100% *everyday*, then you can drop your absorb voltage to as low as 13.8, but no lower, and float as low as you want. You could set float to 12.8, and then as soon as the battery is full, it will start discharging, meaning little to no aging from being at 100%. You could also opt to charge only every other day, but then you are worrying again, and I recommended against that. My personal settings are 13.8 when I am away from the boat, and 14 when I am on the boat using more power.

Also note. If you set the voltage to 13.8, and have no absorption time set, you will not be fully charging your battery. And that is fine. But you may need an absorption time to balance.

Using them between 80 and 20 SOC doesn‘t mean I charge them to only 80% SOC but it means I eg charge to 3,55V but recharge is at 70% SOC. Like this they get a daily top balance but used normally 50-70% SOC. BMS does that automatically daily anyhow, every BMS I know except of Tao BMS where you can set that differently so you cycle your bank deeper.
That’s enough BUT if you have the cheap BMS in cheap drop ins with 100mA above 3,5 that’s simply not enough, you need to keep it in the upper knee longer and more often to simply keep it balanced.If you look additional about voltage rise of cell during charge compared to resting if you eg start balancing earlier at 3.35V that supports top balance .
It’s also the additional fact that you have voltage drops and a MPPT that has 10m cable length (5m one way) the absorption is completely different what battery or MPPT sees.
You have to look at the total picture with all gear involved what is the best practice for that and not take a single factor like top balancing and apply the theories. Then take next factor and look for best practices, that’s how you ruin your drop ins (if not high quality with known cells inside like eg Victron with Winston cells). 5 single factors each best practice does make automatically best practice in sum of your total system.


Top balancing if done without supporting logic only works at the top, correct but if that’s supported by brain power BMS who eg knows which is lowest and highest it works, so start balancing or simply reducing charge of that high cell earlier has some effect…Electrodacus does it and you can adjust it. don‘t know how this works in detail but I see it works.

[CaptainRivet]

Originally Posted by Pete7

He has a Daly BMS and the PWM controller? hmm.

Pete

Not a Daly BMS, that would be great….
He has drop in BMS that’s not communicating in any way externally or can be adjusted, that does cell balancing when, with how many Milli amps, if one cell reaches threshold or all it starts balancing…..all about he doesn‘t know anything, it’s a Blackbox he patched up with a daly Smart balancer getting the unbalanced cells back to balance but doesn’t fix the root cause of them being unbalanced. Daly balancer balances highest to lowest cell but cannot prevent a runner.

[sailorboy1]

You people are on wrong thread

[Pete7]

Originally Posted by CaptainRivet

Not a Daly BMS, that would be great….
He has drop in BMS that’s not communicating in any way externally or can be adjusted, that does cell balancing when, with how many Milli amps, if one cell reaches threshold or all it starts balancing…..all about he doesn‘t know anything, it’s a Blackbox he patched up with a daly Smart balancer getting the unbalanced cells back to balance but doesn’t fix the root cause of them being unbalanced. Daly balancer balances highest to lowest cell but cannot prevent a runner.

He posted this photo in post no 24. However, despite the BT module, it may be an early Daly that didn't have BT, or wasn't connected properly. I think, but would need to check, you can have either BT or the 485 bus to a display screen but not both at the same time.

Pete

[newhaul]

Originally Posted by Pete7

He posted this photo in post no 24. However, despite the BT module, it may be an early Daly that didn't have BT, or wasn't connected properly. I think, but would need to check, you can have either BT or the 485 bus to a display screen but not both at the same time.

Pete

Likely not connected properly

[CaptainRivet]

Originally Posted by Pete7

He posted this photo in post no 24. However, despite the BT module, it may be an early Daly that didn't have BT, or wasn't connected properly. I think, but would need to check, you can have either BT or the 485 bus to a display screen but not both at the same time.

Pete

The BT Module is from the active balancer. That is indeed a Daly BMS, you can adjust a lot and balancing current is 200mA. That makes it worse because that works properly and balances above 3,4V means inappropriate charge sources and parameters caused the imbalance.
Even early Daly you can connect remotely via cable and adjust.
I would throw both out and get a jdk BMS giving full control over the cells that also have active balancers.
@sailorboy: not wrong thread, you are starting to do the same mistakes as solar support but with better equipment that can be easily adjusted correct.
Problem with drop ins you have no control over the individual cells and cannot adjust anything on BMS. And all your charge sources just see the total voltage of 4 dropin in parallel but not the individual cells.
So to keep your bank happy your first goal is to make sure it’s gets it daily top balance and has time to do it=absorption keep it longer at the top end. The only thing you can do to influence your bank can reach HVC and stay in balance is to give it enough time to absorbe so your balancer has more time to do it’s work.
If that’s fine you can reduce it till it’s starts to differ.

[Pete7]

Originally Posted by CaptainRivet

The BT Module is from the active balancer. That is indeed a Daly BMS, you can adjust a lot and balancing current is 200mA. That makes it worse because that works properly and balances above 3,4V means inappropriate charge sources and parameters caused the imbalance.

Problem with drop ins you have no control over the individual cells and cannot adjust anything on BMS. And all your charge sources just see the total voltage of 4 dropin in parallel but not the individual cells.

I don't see the little light on the BT module, so Newhaul likely right, its not connected properly.

Unless the spec has recently changed the 150A Daly only balances with 30mA. However, it does allow you to adjust most of the setting via the BT app. I have been playing with mine to see what happens and for fun

Pete

[sailorboy1]

Originally Posted by sailorboy1

Bulk 14.0V, for 12 minutes (wanted 6 minute but the regulator wouldn't go less)
Ansorption 13,6V, for 12 minutes (same minutes story)
float 13.4V, 6 hours as that is the max
belt programed b-4 (80% max alternator output on my 100A alternator). That works out to the 20a charge the manufacturer recommended, but I really did it to protect the alternator
alternator temp set to 95C (it was 84C today when motoring)

So it has been 6 weeks and I have had to motor a couple times for 6-8 hours and feel the above is too conservative. So I am going to leave the bulk and absorption as is, but increase the float as the setting at 13.4 seems acturally be lower than that at battery (sense wire is at the battery)

[donradcliffe]

I didn't understand what you meant by the 20a charge. If you are only charging at 20amps, I'd tweak the belt manager to get 50 amps. New float setting is OK, but I would also take adsorption time to 1 hour.

[sailorboy1]

Originally Posted by donradcliffe

I didn't understand what you meant by the 20a charge. If you are only charging at 20amps, I'd tweak the belt manager to get 50 amps. New float setting is OK, but I would also take adsorption time to 1 hour.

I didn't say anything about 20a. My 100a alternator is putting out about 80a , staying well below the temp setting/limit. I don't think I will increase the bulk/absorption time or voltage. I am OK with the batteries only getting to 97-98%, but don't really like that 2 hours later they are at 90% because the float on the alternator doesn't kick back in till then.

It is a work in progress and as I get more experience on how it all works out I am more comfortable staying conservative

[newhaul]

Originally Posted by donradcliffe

I didn't understand what you meant by the 20a charge. If you are only charging at 20amps, I'd tweak the belt manager to get 50 amps. New float setting is OK, but I would also take adsorption time to 1 hour.

Don his lifepo4 battery manufacturer recommends 20 amp charging for optimum so keep it at 20 untill warranty runs out at least .

[wholybee]

Originally Posted by donradcliffe

I didn't understand what you meant by the 20a charge. If you are only charging at 20amps, I'd tweak the belt manager to get 50 amps. New float setting is OK, but I would also take adsorption time to 1 hour.

It is important to understand what Balmar means by "12 minutes". That doesn't mean an absorption time of EXACTLY 12 minutes, but a MINIMUM of 12 minutes. The regulator then runs it's program to magically figure out what that time will be extended too-which might in fact be a full hour.

You for sure do NOT want the minimum to be 1 hour. IMHO for LFP it should be 0 minutes. Consider, you motor around, your battery gets to 100%, and you stop to drop anchor. You quickly decide you don' like the spot, start the engine again, and leave. You now have a 100% full battery, and have reset those 1 hour timers. Even 12 minutes at bulk could overcharge the battery. Then follow that by an hour of absorpsion and you could have a real problem.

It is an odd behavior that I don't think any other charger does, and I believe that it is related to whatever algorithm the unit uses to determine the absorption time on a Lead-Acid battery depends on the battery being under charge that the time voltage readings are made. Remember, it cannot measure tail current to end charging, so it does something else. But that information on how the unit works isn't made available.

[wholybee]

Originally Posted by sailorboy1

I didn't say anything about 20a. My 100a alternator is putting out about 80a , staying well below the temp setting/limit. I don't think I will increase the bulk/absorption time or voltage. I am OK with the batteries only getting to 97-98%, but don't really like that 2 hours later they are at 90% because the float on the alternator doesn't kick back in till then.

It is a work in progress and as I get more experience on how it all works out I am more comfortable staying conservative

If float kicks back in at 90%, I would leave it there. Conservative, yes, but not too conservative IMHO. What you don't want to do is get near 100% and hold it there for 8 hours (or 24 hours or 48 hours if you are in some situations) while you motor around. So the point of a low float voltage is that after the battery is fully charged, to stop charging let the voltage settle back down at a lower voltage. But if you are NOT motoring, and just running the engine to charge, it will charge to full (whatever you set that up as).

Now, let's say you are motoring for 8 hours, and expect to reach your anchorage at dusk, and want your batteries to be fully charged before you go to sleep. About an hour before you arrive, turn the key to the engine off. Your diesel engine should keep running. Then turn it back on. This resets the Balmar, and it will go back into bulk. You arrive with the battery full, and shut off the engine.

[newhaul]

Originally Posted by sailorboy1

I didn't say anything about 20a. My 100a alternator is putting out about 80a , staying well below the temp setting/limit. I don't think I will increase the bulk/absorption time or voltage. I am OK with the batteries only getting to 97-98%, but don't really like that 2 hours later they are at 90% because the float on the alternator doesn't kick back in till then.

It is a work in progress and as I get more experience on how it all works out I am more comfortable staying conservative

That's 90% of your battery capacity so 80% of which is usable. It will take a while to change the mindset from FLA to LIFEPO4.
Iirc you are 400ah ? So 90% is 360ah or 340ah usable till sunrise tomorrow . What's the issue ? I know took me almost a year to change my thinking from lead to lifepo4 wrt usable ah

[sailorboy1]

Originally Posted by wholybee

Now, let's say you are motoring for 8 hours, and expect to reach your anchorage at dusk, and want your batteries to be fully charged before you go to sleep. About an hour before you arrive, turn the key to the engine off. Your diesel engine should keep running. Then turn it back on. This resets the Balmar, and it will go back into bulk. You arrive with the battery full, and shut off the engine.

Thats actually what I have been doing, cycling the key to restart the regulator program.

And from a different post; yes my manufacturer says 20a charge ideal. But can do 100a. I have 4 so 80a becomes ideal and depending on the solar and day or night loads I end up with 55-95a into the batteries.