Two year old Relion 100-HP battery bank going south rapidly

JoeC657

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Has anyone experienced big-name LiFePO4 batteries rapidly loosing their ability to hold power after just two years of easy use? I have, in my class C RV, a bank of three 100 ah batteries with 400 W solar, 40 amp controller and 2kW inverter which was used only a few times. The RV was mostly stored, 50% discharged, for 2020. Most usage ran between 50-80% SOC with occasional full charges and one discharge to 10% SOC when we were stuck in southern TX during the deep freeze and power outage. Up until a week ago I saw no sigh of battery degradation. Using the inverter on a fully charged battery bank to cook on a 1500 W convection plate, in a matter of minutes I received "low voltage" warnings. Now, my 7 amp draw refrigerator takes the bank down to low voltage warnings (12.5 volts) in less than 1/2 hour.

The start of this tour began in mid June. A few weeks into it, I did notice that the battery voltage was slightly lower than it should have been for the stated SOC (ah drawdown) from the Victron BMV-712 battery monitor. Other than that, everything seemed normal until there was a larger discrepancy noticed a week or so later. The solar was mostly keeping the battery bank up to near full.
 

Steve_S

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Try to discharge the batteries to 10%, then push at Max Charge Rate is possible (50A) to NO MORE THAN 14.2V (3.55Vpc). It may require 2 possibly 3 cycles. Relion Warranties are GOOD. BUT these were not properly stored per your description... All Lithium based battery systems are more sensitive than brute force Lead and they do not tolerate abuses very well. Very little forgiveness.
 

mikefitz

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Using the inverter on a fully charged battery bank
How do you evaluate that the battery bank is fully charged?
the Victron BMV-712 battery monitor
This can give incorrect readings when the settings are not ideal for the battery type and mode of charging, errors build up over time, it syncs to 100% before full charge is reached.

. Most usage ran between 50-80% SOC
Its reported that micro cycling can lead to 'memory effects' that effectively reduce capacity. A full charge and discharge cycle can erase this effect.

I would charge each battery separately to the maximum voltage specified, 14.6 volts, with a long absorption time to allow the internal balance to function , (14.4 volts stated on the spec sheet), and follow by a load test.
relion spec.jpg
Mike
 

JoeC657

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Try to discharge the batteries to 10%, then push at Max Charge Rate is possible (50A) to NO MORE THAN 14.2V (3.55Vpc). It may require 2 possibly 3 cycles. Relion Warranties are GOOD. BUT these were not properly stored per your description... All Lithium based battery systems are more sensitive than brute force Lead and they do not tolerate abuses very well. Very little forgiveness.
Storage at 50% SOC (by voltage reading and SOC which was tracking well at the time) is incorrect? Says who? I was told by Relion support that this is the procedure for long term (several months) storage.
 

JoeC657

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FIRST before you do ANYTHING else...
Inspect ALL TERMINAL CONNECTIONS FOR DISCOLORATION OR LOOSE BUSBAR...
This spring, April, batteries were all separated and charged to full capacity separately and reconnected after sitting idle for 24 hours after being retested for voltage (within .1 volt). Connections are solid.
 

JoeC657

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How do you evaluate that the battery bank is fully charged?

This can give incorrect readings when the settings are not ideal for the battery type and mode of charging, errors build up over time, it syncs to 100% before full charge is reached.


Its reported that micro cycling can lead to 'memory effects' that effectively reduce capacity. A full charge and discharge cycle can erase this effect.

I would charge each battery separately to the maximum voltage specified, 14.6 volts, with a long absorption time to allow the internal balance to function , (14.4 volts stated on the spec sheet), and follow by a load test.
View attachment 58815
Mike
Specs were never exceeded, not even close. BMV-712 tracked voltage/SOC spot on when charge efficiency was set to 90%, setup indicates 99%. That efficiency never happened. Gross discharge and charge numbers proved this out over time from new. There might have been an issue with the batteries from the beginning. All were charged separately, rested, and checked voltage before connecting in parallel 2 years ago. Only recently have the battery voltage/SOC readings been out of sync, slightly at first (month ago) now grossly.

I only assume full charge with current <.3 amps on the bank AND voltage at 14.6. BTW, charge current NEVER stops completely, not ever. Not sure if this is an indicator of an early issue or not.
 

JoeC657

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Specs were never exceeded, not even close. BMV-712 tracked voltage/SOC spot on when charge efficiency was set to 90%, setup indicates 99%. That efficiency never happened. Gross discharge and charge numbers proved this out over time from new. There might have been an issue with the batteries from the beginning. All were charged separately, rested, and checked voltage before connecting in parallel 2 years ago. Only recently have the battery voltage/SOC readings been out of sync, slightly at first (month ago) now grossly.

Try to discharge the batteries to 10%, then push at Max Charge Rate is possible (50A) to NO MORE THAN 14.2V (3.55Vpc). It may require 2 possibly 3 cycles. Relion Warranties are GOOD. BUT these were not properly stored per your description... All Lithium based battery systems are more sensitive than brute force Lead and they do not tolerate abuses very well. Very little forgiveness.
Thanks. But I'll need a 150 amp charger. Three 100 ah batteries in parallel. Each will take 50 amps. I have nothing that large AND I'm in the middle of a cross country tour, 1000 miles from home. Relion is shipping replacements to me this Friday. And 90% discharge followed by a maximum charge rate seem more like a good spanking to me over casual usage.
 

JoeC657

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Get a battery tester and test them individually
Test for what, exactly? Are there testers especially made for LiFePO4 batteries? Who makes them? I have charge and discharge profiles (graphs of voltage vs current from the Victron BMV-712 SmartBMV app "Trends" page) of the 3-battery bank and individual batteries if you would like to see them. I don't think that anything else would be better than that. I may be wrong. Careful what you ask for... unless you are a battery engineer, you won't know what you are really looking at.
 

Sabre36

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Has anyone experienced big-name LiFePO4 batteries rapidly loosing their ability to hold power after just two years of easy use? I have, in my class C RV, a bank of three 100 ah batteries with 400 W solar, 40 amp controller and 2kW inverter which was used only a few times. The RV was mostly stored, 50% discharged, for 2020. Most usage ran between 50-80% SOC with occasional full charges and one discharge to 10% SOC when we were stuck in southern TX during the deep freeze and power outage. Up until a week ago I saw no sigh of battery degradation. Using the inverter on a fully charged battery bank to cook on a 1500 W convection plate, in a matter of minutes I received "low voltage" warnings. Now, my 7 amp draw refrigerator takes the bank down to low voltage warnings (12.5 volts) in less than 1/2 hour.

The start of this tour began in mid June. A few weeks into it, I did notice that the battery voltage was slightly lower than it should have been for the stated SOC (ah drawdown) from the Victron BMV-712 battery monitor. Other than that, everything seemed normal until there was a larger discrepancy noticed a week or so later. The solar was mostly keeping the battery bank up to near full.
Yes, we've seen ReLion banks with pretty severe capacity degradation. What were your absorbtion & float voltages set to? What was your absorption duration?

Please do not trust your BMV empirically. The SoC calculation can very easily get itself out of sync with the bank. This article explains the nuances of the BMV calculations. Charge to 14.2V or as much as 14.4V and hold voltage for about an hour. Manually re-sync the BMV to 100% and now run a discharge.

The typical degradation issues we've seen all have a few things in common;

Commonality 1 - 14.6V absorption and far too long an absorption duration, 4+hours on some of the banks.
Commonality 2 - 13.8V float, indefinite time
Commonality 3 - Battery space routinely above 80F

The most recent was a colleague of mine who is also a marine electrician. The banks was four RB300 batteries all less than two years old. It was a long fight for him but ReLion did warranty replace the bank when faced with accurate capacity testing data. The boat owner was also a lawyer however, I don't know if that played a role. I do know he read every piece of data Relion ever supplied and was smart snough to point out a number of things they did not specifically exclude in the warranty that could/can degrade LFP.....

Battery 1 - 100% Capacity Loss (completely failed battery)
Battery 2 - 61% Capacity Loss
Battery 3 - 67% Capacity Loss
Battery 4 - 60% Capacity Loss
 
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Sabre36

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Test for what, exactly? Are there testers especially made for LiFePO4 batteries? Who makes them? I have charge and discharge profiles (graphs of voltage vs current from the Victron BMV-712 SmartBMV app "Trends" page) of the 3-battery bank and individual batteries if you would like to see them. I don't think that anything else would be better than that. I may be wrong. Careful what you ask for... unless you are a battery engineer, you won't know what you are really looking at.
I'd love to see that discharge graph.
 

JMc

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I often hear people make suggestions to run charge/discharge tests on individual batteries. These are typically multi-hour regimes that involve equipment and careful monitoring by a competent technician. In the real world those people don’t work for free, and even for DIYers it has a cost in time. A $500 battery that costs an additional $250 to test is not a $500 battery.
 

JoeC657

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I'd love to see that discharge graph.
Battery bank discharge.png
This is a two year old 300 ah LiFePO4 battery bank discharge profile. I have the individual battery discharge profiles too. Very similar but things happen much quicker.
 
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Steve_S

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A Good bench Powersupply capable of CC/CV Charging is not a crazy expense. I paid $189USD for a 15V/45A Volt/Amp adjustable Bench supply which I use to Top Balance Cells and even tweak 12V Packs. Now a 15V/10A or 20A bench supply is <$100 USD. I do love the Dramatics though... worth a chuckle.
 

Sabre36

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From the charge voltage down to about 13.3V or so will be near vertical, as you can see, because there's no stored energy up there. Your current pulses are high current, 80A or so on the last pulse, but the voltage is rebounding. Having been doing LFP since about 2008 all I can say is that graph is inconclusive. If I shoot from the hip it looks a lot like a bad connection or a BMV voltage sensing location issue. Charge to full and apply a steady 10A+/- load and lets have look at that graph. All batteries could be degraded, none may be or maybe it's just a bad connection or a single bad battery. Clean test and confirm all connections, charge, zero BMV, then run discharge at a steady load...
 

JoeC657

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Yes, we've seen ReLion banks with pretty severe capacity degradation. What were your absorbtion & float voltages set to? What was your absorption duration?

Please do not trust your BMV empirically. The SoC calculation can very easily get itself out of sync with the bank. This article explains the nuances of the BMV calculations. Charge to 14.2V or as much as 14.4V and hold voltage for about an hour. Manually re-sync the BMV to 100% and now run a discharge.

The typical degradation issues we've seen all have a few things in common;

Commonality 1 - 14.6V absorption and far too long an absorption duration, 4+hours on some of the banks.
Commonality 2 - 13.8V float, indefinite time
Commonality 3 - Battery space routinely above 80F

The most recent was a colleague of mine who is also a marine electrician. The banks was four RB300 batteries all less than two years old. It was a long fight for him but ReLion did warranty replace the bank when faced with accurate capacity testing data. The boat owner was also a lawyer however, I don't know if that played a role. I do know he read every piece of data Relion ever supplied and was smart snough to point out a number of things they did not specifically exclude in the warranty that could/can degrade LFP.....

Battery 1 - 100% Capacity Loss (completely failed battery)
Battery 2 - 61% Capacity Loss
Battery 3 - 67% Capacity Loss
Battery 4 - 60% Capacity Loss
Thank you for the info. My charger is a Progressive Dynamics PD4655LIV, specifically designed for lithium batteries and has no adjustments or settings. Just a lithium configuration jumper wire (installed). It replaced the WFCO panel standard battery charger/power supply installed in the RV. I have a chart next to the battery monitor panel and it lists the typical battery voltage at the various SOC levels. I have compared it to the printed graphs of the power curves supplied by the manufacturer and it's accurate. I always check the voltage vs SOC to look for discrepancies and monitor my batteries dozens of times throughout the day while I'm underway. While driving I'm frequently looking at charge current from the solar, alternator (if enabled) and generator (if running) along with tire pressures and temperatures (RV and towed vehicle). Occasionally I look to see where I'm going :). Relion is sending to me a new set of RB100-HP batteries. I spent the extra $1000 to get batteries that had a higher peak load capacity just to ensure that I would not over-tax the battery bank when starting the 4kW generator (up to 280 amps, manufacturer spec.). I tried to think of everything while designing this system and put in plenty of margin. Did everything to manufacturer's specifications. Monitored the system like a hawk. But still ended up here.

When I bought the batteries two years ago there was no mention of using the -HP batteries for starting RV generators; that was my idea. Now read the marketing literature on the -HP batteries; they are all over the high demands of RVing and starting generators. Three standard 100 ah batteries can supply enough short term amperage to start the generator under the worst conditions (280 amps), but again, it was too close for my comfort level so I spent an additional $1000 to get better peak performance and greater margin of performance. So, tell me where I went wrong. I can't figure it out. Seems like I'm in the same "boat" as your colleague.
 

JoeC657

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From the charge voltage down to about 13.3V or so will be near vertical, as you can see, because there's no stored energy up there. Your current pulses are high current, 80A or so on the last pulse, but the voltage is rebounding. Having been doing LFP since about 2008 all I can say is that graph is inconclusive. If I shoot from the hip it looks a lot like a bad connection or a BMV voltage sensing location issue. Charge to full and apply a steady 10A+/- load and lets have look at that graph. All batteries could be degraded, none may be or maybe it's just a bad connection or a single bad battery. Clean test and confirm all connections, charge, zero BMV, then run discharge at a steady load...
The first 1/2 hour was a steady load of about 8 amps, my refrigerator plus one LED light. Going to 13 volts with that light load on three 100 ah is normal? The stacked loads were to show overall poor performance under modest RV loads, less than 30 amps per battery. And that load generated low voltage warmings. Look at the time line at the bottom. All this happened very quickly. This is just a small sample of the issue. When I first noticed this problem, I was cooking dinner (10-15 minutes) with the 1500 Watt induction plate running off the inverter. This is not a continuous load, it pulses to maintain pan temperature to set temperature. I got about 60 low voltage alarms and dropped the bank momentarily to 11.2 volts from a starting full charge minus about one hour of the refrigerator running (8 amps). I've used this cooking device before without any issues. The bank charged back in less than one hour using the RV power supply running off the generator; a maximum of 40 amps initial charge rate. A total of maybe 30 amp hours which would have charged a 90% SOC 300 ah battery bank, not a completely discharged bank. These batteries have very little capacity left in them and I think the graph shows that.
 

Sabre36

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Thank you for the info. My charger is a Progressive Dynamics PD4655LIV, specifically designed for lithium batteries and has no adjustments or settings. Just a lithium configuration jumper wire (installed).
Ah now we're getting somewhere. Your problem is because Progressive Dynamics has NOT A CLUE how to charge LiFePO4 batteries. They simply slapped a "Li" profile (Li batteries are not rechargeable so really should be Li-Ion or LiFePO4 this shows how little they actually know) on a constant voltage power supply.

Your charger NEVER drops to float. It provides 14.6V forever or until you manually turn it off.

Sadly you're not the first person to be mislead by BS marketing by a lead acid charger company who has not a clue what they are doing with LiFePO4. We get called to consult on a few RV installations and we've seen this same charger ruin more than a handful of banks, and we're not even in the RV industry.

Scrap that boat anchor of a charger and get a real charger, one that is 100% custom programmable (Victron IP22 or Skylla IP65 are both excellent) for your next set of Relion batteries or you will destroy them too.

Please understand that this is not the fault of Relion, it is 150% the fault of Progressive Dynamics and your installer who also did not know what they were doing..

Sadly this industry has become the wild west of BS..... It is so damn frustrating.

The problem is your installer not follow the Relion charging guidance and trusted a charger manufacturer to be honest. Trust me when I say the vast majority of charger manufacturers trying to play in this industry are lying through their teeth!

Your maximum absorption time is 0-6 minutes at 14.0V to 14.6V

Your "charger", and I used that term jokingly, is 14.6V CONTINUOUSLY

It never drops to float......


171852253.jpg
 
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