Dead batteries in service, again.

[Overland]

So I woke up this morning to an alarm from Victron telling me that they'd lost the connection to our trailer.  A quick check showed that the batteries had been run down to zero.

 

This is the second time that Oliver has allowed them to run down while in service, in two visits.  This time there wasn't much turned on other than the various monitors, which draw about an amp total.  That would have lasted 12-14 days normally, but Oliver worked on it a few times during the last week and had some things plugged in, so we lost a few days' time.  It also looks like someone may have turned the fridge on, or left something plugged in that added another amp to the draw for about three days.

 

Hopefully no harm done to the lithiums but I really wonder how often they allow the same thing to happen to other customers' trailers with lead acid batteries.  I mean, I'm pretty sure that we're the first customers to have remote monitoring, so if Oliver has allowed other customers' batteries to fully discharge, how would we know?

 

Anyway, I was willing to give them the benefit of the doubt the first time, but twice in a row?  Jeez. I've emailed Jason and copied Scott, asking them to put something in place to keep this from happening again.  But frankly, given my experience, if any of you have left your trailer at Oliver for an extended period, I'd just assume that they allowed your batteries to fully deplete while there.

[rideandfly]

If I remember correctly you have Battle Born Batteries. Reading their following link how 100% DOD of their LIFEPO4 will not have long term effect giving 3000 cycles or more at this DOD:

 

https://battlebornbatteries.com/depth-of-discharge-li-ion-deep-cycle-batteries/

 

Edit: I really like Battle Born LIFEPO4 Batteries, but decided to go with AGM batteries to replace the original batteries for our type of camping with shore power 99% of the time.

[Try2Relax]

Sounds like, if having factory service done, it is a good recommendation to have a battery post disconnect switch installed on your system and in use. It's also a good winter storage item to incorporate

[BlaiddDrwg]

During our factory tour, I asked about a battery disconnect switch and  our guide (Brett) replied that one existed.  I don't remember the location he stated.

[Overland]

Oliver used to install a disconnect, but they don't anymore.  I was really surprised when they told me it didn't.  I've got disconnects now on both the batteries and the solar panels, so that I can work on it without worry.  Although, unfortunately, I was actually in the process of moving the battery disconnect when I took it in and the switch is bypassed and sitting in the back cabinet right now, lol.  Eventually I want to put in a manual transfer switch as well, so that I can bypass the charger if something ever happens to it.  As it is, if it were to ever have a software glitch or something, it would leave me without 120 - not the end of the world but worth attention in the long run.  What I'd really like is to replace the distribution panel with a nice custom Blue Sea panel that incorporates the disconnects and transfer switch, but they're quite proud of those things.

 

I'm not worried about my own batteries, but given that Oliver has a 100% track record now of allowing them to fully discharge in service, I'd find it hard to believe that it hasn't happened before with someone else's trailer.  They just need to put a policy in place where when someone comes in every morning that they check the state of charge for all the trailers in service and check off that they're charged enough for the day.  And they probably need to make sure that all the trailers are plugged in for the weekend or holidays.  I think it's one of those things that when they just had one or two trailers in service at a time, it was maybe easy to keep on top of, but now that they have six or seven in at a time, which is what I've seen on my recent visits, it needs to become part of a routine and checklist.

 

BTW, everything popped back on line this morning.  Could be that they just now got around to plugging it in, but I bet that they only realized this morning that they had to cycle the charger to get it to turn back on and so it was plugged in yesterday without doing anything.  That's caught me out before - it's an easy thing to overlook even if you know about it.

[SeaDawg]

Glad everything is working for you again.

I'm a little confused, though. I thought from your December post that your system was designed to shut down at 10 volts? Did that not work this time?

I'm curious, as someday, when our agms die their natural death, we may consider the lithium batteries. If nothing else, for the dod.

By the time our agms die, perhaps the lithium price will be a little more in reach.

Sherry

[Overland]

Yes, it worked as designed. The batteries shut off at around 9.7 volts this time. The problem is that the charger won’t kick on automatically when it gets power back since the control panel for it runs off 12 volts and if the batteries are dead the panel can’t tell the charger to turn on.  And the batteries won’t kick back in and give the panel power until they see a charge so you’ve got to break that loop to get the system charging again. The solution is to unplug the panel and the charger will then work independently.

 

It’s not intuitive, and is really a bit of a pain since you have to unscrew the cover of the charger to unplug the cable from the panel.

[John E Davies]

The problem is that the charger won’t kick on automatically when it gets power back since the control panel for it runs off 12 volts and if the batteries are dead the panel can’t tell the charger to turn on. And the batteries won’t kick back in and give the panel power until they see a charge so you’ve got to break that loop to get the system charging again.

Your system is already way too complicated for my tastes, but how about this?

 

Can you figure out a way to have a small backup battery wired into the charger control circuit, a "keep alive" battery, that will allow the charger to come back online when the shore power is reconnected?

 

I don't have a clue how well this would work, I'm just thinking aloud. For example, I use a "memory saver" OBD2 adapter harness connected to my lithium battery jump starter box when I remove the truck battery, it keeps  the ECU and other systems happy and you don't lose any of your custom settings. Could that type of setup work here?

 

Seems as if a small lithium battery would keep your charger happy indefinitely, until the shore power comes back. Does the manufacturer of the charger have anything to offer about this? I personally dislike having lots of little lithium batteries sitting around in my trailer, like my hand vacuum, but the Harbor Freight Viking unit is lithium iron phosphate based and does not pose a fire risk like conventional lithium cells.... https://www.harborfreight.com/lithium-ion-jump-starter-and-power-pack-62749.html

 

If I am completely off base, just tell me to go away ;)

 

John Davies

 

Spokane WA

[Overland]

The system could be simplified by omitting the color control panel, since the charger works (or can work) autonomously.  But I think the graphic display on the color control is a large part of the benefit.  Once you understand why the system isn't working on restart, it makes sense because part of what you want the CC to do is turn the charger & inverter on and off.  What Victron should really do is add some code to the charger that tells it to switch to autonomous mode until it can detect a signal from the CC.  I also suspect that if I used the Victron batteries and BMS, then the system would come back to life on it's own since they would all be talking to one another.  The Battle Borns are unable to communicate with the Victron, or anything else, so they can't say 'hey charger, we're shutting off power to the control panel so when you get power back, pretend for a few seconds that it's not connected'.  But it's really not a problem, since running the batteries down isn't exactly part of the regular plan.

 

When I slightly rework things though, I do want to add a split in the UTP cable so I can just unplug it there instead of opening up the charger.

 

The charger also has a second 12v out, which I believe isn't switched.  If I can tap into that to power the CC, then problem solved.  Oliver has my manuals right now so I can't check.

 

Anyway, yes, this sort of system is naturally going to be more complex, but it's just this sort of situation where the benefits seem clear.  It alerts me remotely when something goes wrong, and shuts down fairly elegantly to save the batteries.