Need help configuring Outback charger/mate/mppt to new ReLion Lithium batteries

[seahag]

Just purchased two 300 amp hour batteries, which are connected in parallel on our catamaran. So far cannot convince the Outback system to charge them above 13.2 volts despite setting for absorb at 14.6 per manufacturer recommendation. We have day after perfect day of trade winds and sun but I can't gain any amp hours over what we are taking out no matter how conservatively we use the bank. I went through a lot of programming with Outback people in their ridiculous system of tech support before being told that they could not continue for liability purposes. Meanwhile, we have a warm fridge and not getting a good enough charge to run an electric winch or the windlass.

Does anyone have experience with Outback products and Lithium technology? I need to convince this system to charge to higher voltage and quit wasting valuable charging days!

[sailorboy1]

I have an Outback controller and it does 14.8 for absorption like I programmed it. But it would get to that till state of charge gets to around 97%. Until till it will dump in amps amd voltage will slowly go up till close to being charged.

So when you say your controller wouldn’t do the voltage, what’s the ams and what KE does the controller say it’s doing?

[seahag]

Originally Posted by sailorboy1

I have an Outback controller and it does 14.8 for absorption like I programmed it. But it would get to that till state of charge gets to around 97%. Until till it will dump in amps amd voltage will slowly go up till close to being charged.

So when you say your controller wouldn’t do the voltage, what’s the ams and what KE does the controller say it’s doing?

Hi, thanks for the reply. I don't know what you are asking about ams and KE-can you elaborate?

[sailorboy1]

On the controller, what voltage, amps, and kw does it say it is putting out. Do you have a battery monitor, if so what amps does it say the batteries are accepting?

[sailorboy1]

My iPad sometimes thinks it knows what I’m typing and changes it

[seahag]

Yes I get the same problem! It's dark now so not sure what to tell you- I ordered a Victron bmv 700 monitor to help measure amps in/out as the Outback Mate is always showings the amps in/ amps out as very close together, not realistic!

[john61ct]

First off, for LFP longevity you should never charge as high as the maker says.

3.65Vpc is an absolute max, way higher than the 3.45Vpc that will make them last a long time.

Adjust Absorb to 13.8V and Float to 13.1V and see how you go.

That's an expensive bank of sensitive chemistry to be mucking around with like that.

Do you know the cutoff parameters of the internal BMS?

Verify actual charge outputs with a known good DMM and ideally an ammeter - never trust the charge source's view of what's going on.

Turn off all temp compensation.

Also systems should be tested, configured and maintained from reliable shore power.

[seahag]

Originally Posted by john61ct

First off, for LFP longevity you should never charge as high as the maker says.

3.65Vpc is an absolute max, way higher than the 3.45Vpc that will make them last a long time.

Adjust Absorb to 13.8V and Float to 13.1V and see how you go.

That's an expensive bank of sensitive chemistry to be mucking around with like that.

Do you know the cutoff parameters of the internal BMS?

Verify actual charge outputs with a known good DMM and ideally an ammeter - never trust the charge source's view of what's going on.

Turn off all temp compensation.

Also systems should be tested, configured and maintained from reliable shore power.

Thanks Jon,
I have disabled the temp sensor and yes, understand about not charging that high. For now, that's the opposite problem as we can't get the charge above 13.2 V. I don't know what the internal parameters are set to for these batteries. I have not gotten a lot of information or help from ReLion. Check out their website and tell me if I'm missing something, but it seems like they are all about sales and not support.

[john61ct]

Find the user manual PDFs online, read through and post links to them.

Try what I suggested, if the actual output is too high the internal BMS is quite rightly isolating the cells from damaging over voltage.

[44'cruisingcat]

How much solar do you have? You might be simply using more power than you're recovering.

For lithiums, I have absorb set to 13.8 volts, float at 13.3.
I have the absorb time ("advanced" menu) set to 0.01 hours.

[smac999]

how full is the battery and how big are the panels? they could be in bulk and simply too small to get the voltage higher. turn off all loads and try it with a full battery. (plug into shore for ~24h)

[seahag]

We have three panels at 300w each, plus a wind generator. While working through this we are keeping our usage way down from what we did with 6 year old agms. I will try the lower settings today even though it seems counterproductive, especially considering ReLion uses this as a selling point: they claim you can recharge these batteries in three hours throwing 100 amps into them. If the internal BMS allows that, and they recommend bulk charging at 14.6 and floating at 13.8 then why would a lower charging voltage help me get to a higher level? But since I have tried so much to get the Outback system to do this I am willing to try another take on it and appreciate the help. It makes at least as much sense as anything else.

For the poster who asked about how full the batts are- I don't know. If have a victron bmv on order to help with that but for now, only readings available are through the Outback, which knows nothing about my amp hours. Since the batteries are sold at roughly 50% of their capacity and I feel like we have gained very little ground in 13 days, my guess is that they are still at about 50%. Every day it shows my ah in just slightly above my ah out, and I don't trust the readings because using the "now" meter shows the same situation no matter if it's sunny or dark or windy or less windy. Doesn't make sense. When the wind gusts, the fan speed will pick up and lights may get brighter at times.

[seahag]

Originally Posted by smac999

how full is the battery and how big are the panels? they could be in bulk and simply too small to get the voltage higher. turn off all loads and try it with a full battery. (plug into shore for ~24h)

No shore power available. We are anchored off an island with no marina.

[44'cruisingcat]

900 Watts is a decent array. After a sunny day, when you look at the history, (press the second button from the left) how many amp hours does it show, and what peak amps?

[john61ct]

Have you located links to and read the documentation yet?

I missed your wind power, does that have its own separate charge controller? Need a third link for that then.

You are correct in not paying much attention to the Outback's opinion of SoC, few charge sources can do that without integration with a shunt-based BM.

Your BM will not be accurate until it's properly calibrated, starting with your defining a 100% Full SoC using an accurate ammeter.

These alternative energy sources are just complicating things for now. All this type of commissioning and owner-learning work should be done **on shore power** with a known-good power supply or quality adjustable mains charger.

Plus if course verifying the quality of your wiring infrastructure with your DMM, another potential cause of your symptoms.

Once you are familiar with the bank's behaviour under regular dis/charging cycles, and ideally get the BM properly adjusted and calibrated, then you will be in a position to manage the more variable wind and solar charge inputs.

Originally Posted by seahag

I will try the lower settings today even though it seems counterproductive, especially considering ReLion uses this as a selling point: they claim you can recharge these batteries in three hours throwing 100 amps into them. If the internal BMS allows that, and they recommend bulk charging at 14.6 and floating at 13.8 then why would a lower charging voltage help me get to a higher level?

Sorry if I wasn't clear. LFP bare cells would have no problem with even 500+A (temp protection, suitable wiring / CP infrastructure, full recharge in an hour.

But these so-called "drop-in" style batts have protective circuitry between the external posts and the internal cells.

I'm speculating that the BMS may be isolating the internal cells upon detecting an overvoltage condition.

That is why I recommend trying a 13.8V Absorb setting. That should not significantly reduce the amps charge rate accepted.

As a separate issue, many experts at LFP **House bank** usage (as opposed to the usual high-voltage and currents propulsion usage like EV) recommend staying around that lower 13.8V level for all daily-use charging, for greatly increasing bank longevity, maybe tripling cycles lifetimes or more.

But as long as your LFP bank have always been reading 13+ volts at rest, it is unlikely they have been significantly damaged.