LiFePo4 Battery - disappointing experience so far - comments/guidance appreciated!

Good2go

Hi - I switched out my dealer supplied Lead Acid Deep Cycle marine battery - believe it is a 75aH - for a Weize 100 aH  self heating lithium.  I have a 22 Tab 320 Boondock equipped with the factory solar panel.  I went into the settings menu of the Victron controller and selected the smart lithium LiFePo4 option.    This setting provides absorption voltage at 14.2 V. and Float at 13.5. Temp comp is disabled.  My issue is that I frequently Boondock and was hoping that the Lithium battery might provide more than one day of usage - I do run the Isotherm fridge on a low setting, and try to use other power conservatively.  I feel as though I was able to get a full two days out of the original battery.  Am I being unrealistic in hoping for better performance from this battery? Unlike the lead acid battery, this one shows either full or almost full on the Tab's control panel - then suddenly when its done everything just shuts down - no warning. Should I have spent the $$ and gone with BattleBorn - or do I need two? Would appreciate comments from those who know more about this than I do! 

Thanks!

TV '21 Highlander Hybrid

Marceline

If you haven't installed a SmartShunt I would recommend it. It would really help you to understand how much power is going into and out of your battery. Are you starting with a full battery? How much power are you getting from solar (the Victron controller should give you info on that)? I understand that the Isotherm fridge will consume 40-50 amps per day, so will need to replenish even a lithium battery. 

webers3

I installed a different budget brand lithium in my 2017 320, I also use use power conservatively but don't have the same experience as you. If you were able to go two days on 75Ah lead acid battery but not able to go full day on 100Ah lithium something is off. As @Marceline suggested you need to have some kind of monitor to see how much power is going in and out. With 100watt solar I can run the fridge for most of the day but will have to recharge the battery the next day.

Good2go

Just to add to the above, when it's sunny out - no issues. Charges fine and runs everything - but on a cloudy day...no joy.

NorthIsUp

Although it's not a BB, take a look at their recommended Victron settings. https://battlebornbatteries.com/programming-a-victron-smartsolar-charge-controller/
Your settings are only slightly off of their recommendations.

Good2go

Sorry - a bit more information - looking at the history tab in the victron app, it appears that there is a battery consumption line - I believe this would show the usage?  At any rate, it has not been over 10Wh at any time - it this bogus or am I misreading it?  I'll attach a couple of screen shots - please refer to "5 days ago" - the sun was shining and the fridge was on just preparing for a short trip. 4 days ago was raining and the camper was under tow - looks like the TV will only charge up to 13.3 V though the panel charges to the preset 14.2 volt.  3 days ago and 2 days ago, raining/cloudy  lost power and plugged into the TV to recharge, but strangely 0 Wh consumption (if it IS consumption). "Today" tab - towed home on the sun (of course!). Does any of this information assist you with whatever may be going on?  Would a Smart Shunt provide additional information beyond this?  Thanks for your help - would like to decide on a path forward to improve this situation.

Good2go

Good2go

Grumpy_G

One thing that sticks out is that for several days the min battery voltage is zero. This means the battery was fully discharged and turned itself off. As you discovered, voltage is not a good indicator of charge state for a LiFePo battery. The battery has little reduction in voltage as it discharges and just turns completely off when the capacity is exhausted. 

pthomas745

The monitors in the trailer were always sketchy before, since they cannot measure a lead acid battery accurately with the battery switch on.  Now, with owners changing to lithiums, the Kib monitor should be tagged with a warning label.   A lithium battery state of charge, almost all the way down to 10 percent capacity, will still register at about "50 percent" state of charge on the KIB.  The KIB only speaks "lead acid".  A lead acid battery will read 12.6 when it is "fully charged".  A lithium battery will read above 12.6 volts until it drops below 20 percent capacity!  So, the KIB will always tell you your battery is "fully charged" if you have a lithium.  This has caught several owners over on the FB pages, so you are not alone.  It should never be used for "checking" a lithium battery.

How long ago did you change out the battery?  Sounds like you have the lithium setup correct, but...the "maximum" charge you are getting (on the history page) of "13.6 to 13.20" is no more than what a lead acid battery would be getting while charging.  Check those Victron battery settings again.

The problem may be: the battery was disconnected....and then reconnected.  The solar controller was still getting some power from the solar panel.  The "old skool" method of connecting a solar setup was: connect the solar controller to the battery first, and let the controller check the battery status, etc.  And then connect the solar panels and let the controller do its job.

So, try this: disconnect your solar panel cables (or just the negative cable) at the solar controller.  Disconnect the negative of the battery cable at the controller.  Let it sit for a moment. Reconnect the battery cable first, and give it a few moments.  Then reconnect the solar panel. Check the input from the panel with the sun up.

Wild guess: you replaced the battery in the trailer about 5 days ago?  That was the last time your battery was in absorption/float mode.

Marceline

Did you try to bring your fridge down from ambient temperature to 40deg from battery power by any chance? If you did, you probably completely emptied your battery. It takes an enormous amount of power to cool the fridge - esp if it’s 80-90deg outside.

If you can’t bring your fridge down to 40deg using shore power (say you keep the camper in a storage yard) you need to find another way to do it. I used to chuck a piece of dry ice in there. 

The solar controller will only show you how much power the solar panel is putting into the battery. It won’t tell you how much power the camper is consuming. You need a SmartShunt for that. 

Good2go

Pthomas, Grumpy and Marceline - thx for your comments.  Correct that I cooled off the fridge on a hot day without shore power, and that the Kib monitor always shows full until the battery suddenly dies.  I actually replaced the battery in April  - with the sun shining it achieves the 14.2 setting each day and then enters float - I'll  post a pic below showing these cycles as it's just sitting in the yard doing its thing. Looks like I need a SmartShunt as suggested to do a better job monitoring.  Any thoughts on the best path forward? i.e. does it appear the battery is OK, just over taxed? A second one in parallel?

Good2go

SLJ

My Renogy shunt/battery monitor takes all the guesswork out. Everything going in or out always displayed at a glance. No phone app needed. I highly recommend it. This was on an overcast morning with my 105 watt panel on the roof and my 200 watt Renogy suitcase. Shows I used seven percent since the previous day (12 volt fridge, pump, lights, etc.)

pthomas745

The Victron app, with just the controller, does have plenty of indications of whether or not the trailer is charging.  On the status page, the "Current" indication will show if power is being removed from the battery or power being added. 

I really don't think the Danfoss 2 way fridge uses very much more power in various conditions.  The compressor my cycle longer, but my portable fridges cycle on and off while cooling .  But the thought the fridge will use 90 amp hours in a day seems a bit off. 

So, if you could show us your status page with the sun up this morning?  Is your solar actuall working?

Horigan

@Good2go, I would consider bumping your absorption voltage up to 14.4V or 14.5V and your float to 13.6V.  That won't totally address your issue, but it will help a bit.  Many manufacturers recommend 14.6V absorption, but I like 14.4-5V as a good compromise.  Does your battery manufacturer have recommendations for charging voltages?

Marceline

Good2go said:

Pthomas, Grumpy and Marceline - thx for your comments.  Correct that I cooled off the fridge on a hot day without shore power, and that the Kib monitor always shows full until the battery suddenly dies.  I actually replaced the battery in April  - with the sun shining it achieves the 14.2 setting each day and then enters float - I'll  post a pic below showing these cycles as it's just sitting in the yard doing its thing. Looks like I need a SmartShunt as suggested to do a better job monitoring.  Any thoughts on the best path forward? i.e. does it appear the battery is OK, just over taxed? A second one in parallel?

I think the battery is fine. I think that you drew it down to zero by using the battery to bring your fridge from ambient to 40deg, then you didn’t have enough solar to bring the battery back up because of the bad weather. You’re not going to get away with using the battery to pre-chill  your fridge unless you have plenty of sunshine so the solar can keep up with the heavy load. I wouldn’t try it. If you plan to do a lot of boondocking I would get the SmartShunt. 

Marceline

Good2go said:

The “min” number is the voltage at night when there’s no solar input. My trailer is an hour away, so I can’t double check, but I’m pretty sure that number should be at 13.4 and as high as 13.6. I think that something must be wrong in your controller settings and you’re not putting a full charge on the battery. So when you started pre-chilling your fridge off the battery, you weren’t even starting with 100aH. More like 70aH. 

Good2go

I've since identified that I have the WFCO 3875 AD  auto-detect converter, and that it is indicating a green LED, which I believe means that it is in Lead Acid mode, and so could not charge a lithium battery fully. I believe it should show a blue LED when it detects lithium; apparently this model sometimes has trouble detecting a lithium battery. From other threads regarding this controller, apparently if you discharge the battery and then turn the converter on, it is more likely to sense the lithium battery. I'll give that a try.

Marceline

Good2go said:

I've since identified that I have the WFCO 3875 AD  auto-detect converter, and that it is indicating a green LED, which I believe means that it is in Lead Acid mode, and so could not charge a lithium battery fully. I believe it should show a blue LED when it detects lithium; apparently this model sometimes has trouble detecting a lithium battery. From other threads regarding this controller, apparently if you discharge the battery and then turn the converter on, it is more likely to sense the lithium battery. I'll give that a try.

I thought that you had your trailer in a location where you don't normally connect to shore power, and that's why you tried to use battery power to cool your fridge from ambient temperature. Do you normally store your trailer in a place where you can connect to shore power? Are you using your converter (shore power) or your solar panel (Victron Controller) to charge your battery at home?

Good2go

Generally I leave the trailer parked in a sunny location and let the solar do it's thing. @Horigan above suggested adjusting the parameters in the Victron app for charging limit and float to match the battery manufacturer recommendation, so I did that - each increased .3V over the standard setting.   I ran the lights and fridge overnight to discharge the battery to its cutoff point, then plugged into shore power on the hope that the converter would recognize the lithium - I saw the blue LED flash a bit, then went to the green LED, so still apparently isn't sensing the lithium.  And just now I noticed a red LED on in addition to the green, so now I have to look that one up to see what that indicates.

Good2go

Success!! - maybe....cycled the shore power a few more times and now the blue LED is on; the green and red are off so hopefully this indicates the converter has detected the lithium battery.  Time will tell - it always does!

Good2go

A couple more possible dumb battery/solar questions.... I'll attach a pic below. 1) moderately sunny; running just on solar, charge state is "off".  Solar voltage shows around 15....if the lithium battery is discharged and cuts out at 10.8 volts, and the solar won't charge until there's a 5V difference between the solar voltage and battery voltage (per the Victron app) how does it ever charge???

2) in the pic below; the status is as above (no shore power, just solar on) why does the battery current show 5.5 Amps?  what does this indicate?

3) While the converter finally showed the blue LED indicating that it knew it was charging lithium, while I had shore power on the battery voltage never went above about 13.5V. Is this normal?  The converter says it should achieve 14.6 for lithium.  Still trying to get a full charge....thanks for everyone's help.

Good2go

pthomas745

If you are looking at the "Load" section and thinking that means the charge state is "off", that is not correct.  The load "function" is a completely different planet from our battery charging discussion here.  So, ignore that part.

The solar is cranking 78 watts.  Great.  The battery voltage is showing 13.49, but that is basically what the solar controller is sending to the battery.

The "current" section is showing a "positive" value of 5.5 amps going into the battery, and the charging stage is "bulk" mode.  As the battery reaches about 85 percent or so, the charge will begin to taper off.

This link goes to a blogger who created an annotated Victron App explainer.  Scroll down to the section that says "Monitor the SmartSolar Solar Controller".

https://faroutride.com/victron-review/?fbclid=IwAR0S300K9ZY-56b-WoMT-9KFW6f3fA-LVt9MlfdN4roBTNceRj6j9Kaneig

Good2go

Thanks @pthomas - that video was helpful.  Today I disconnected the battery from the system, and attached my LiFePo4 rated charger and let it run until it indicated "full" which I thought would be 14.6 volts.  When I reconnected the battery, the converter still recognized it as lithium (blue LED) but the battery voltage showed about 13.5 V in the victron app.  Is this normal?  I do see in the history that it read 14.67 at some point today, not sure how or when that data point was collected as the battery was out of the system - and when reconnected immediately read 13.5.

Good2go

So...it was connected to shore power for the morning, the blue LED was on; I can only assume it achieved a full charge based on the history - pic below.  But I'm left wondering why the charger I used this afternoon with the battery disconnected indicated only 60% or so, then charged successfully according to the charger readout, then immediately indicated 13.5 in the app.  Very confusing, guess I'll just take it camping and see if it all works better!  At least the blue LED is a step in the right direction.

pthomas745

There is a difference between "charging voltage", or the voltage required to charge a battery, and "charged voltage" the voltage that indicates the "state of charge".

So, your battery at 13.6 "rested" is at full charge.

Good2go

That helps clear things up!  Thanks! Just going to use it now and see how things work out.

Good2go

Also, Nucamp forwarded this video to help with forcing the converter into lithium mode, and also explains the Red led (indicates charge mode) which I had not previously seen discussed.

https://www.youtube.com/watch?v=-pFuVnUsPz4

pthomas745

What this video shows is a 100 percent design failure.