Lithium battery disconnect

[Ron C.]

Great info, Rlum. Thanks so much!

[Ron C.]

Do not have electrical schematic, but will take a closer, more detailed look. Thank you.

[Davydd]

Originally Posted by Davydd

Just putting a disconnect on is not going to do it. The batteries will still be subject to freezing damage at -4F (-20C). You have to remove them and store inside a climate controlled space, apply heat from shore power if it stays in the van, or store the whole van in a climate controlled storage garage.

I just want to reiterate what I posted previously if you want to winterize and store outside unattended over the winter anywhere in Pennsylvania. There is a natural loss of power with totally disconnected batteries but lithium ion should get you through a winter better than AGMs. I still can’t believe Pleasure-way did not provide a disconnect, but I said it doesn’t solve your problem. If you have shore power an electric resistant heating pad placed locally under the batteries would probably suffice if the batteries were left in the van outside. However, when you analyze it, you don’t have control at the other side of the temperature scale you could overheat your batteries. You could apply heat throughout your van with an electric thermostat Controlled electric heater but I think that would be overkill.

So, I guess Pleasure-way must think you have to remove your batteries (which means disconnect) and store them inside a climate controlled space because if they are not disconnected you have other loads drawing power other than just natural loss. They call them vampire losses but they are really idiot lights, direct connect alarms, stand by and such. Or you could store in a climate controlled garage with shore power.

[markopolo]

Originally Posted by GeorgeRa

Most RV I have experience with had a battery disconnect, a simple manual switch or a remotely controlled like a BlueSea one. A switch should be on the red positive finger size cable somewhere close to the battery and before the fuse/CB panel, you could try to trace the cable.

Originally Posted by booster

Our Chevy Roadtrek didn't have a main battery disconnect, only the 12v power to the coach bistable relay. If you wanted to kill all power to everything you had to pull the cables to both batteries.

As George noted, most motorized RV's have a battery disconnect. However, as Booster points out, those disconnects typically only disconnect house loads to prevent discharging the battery. Charging from the alternator for example is not disconnected.


Snippet from a 2018 PW owners manual:

WARNING: Do not charge your batteries below 32 degrees F or 0 degrees C. Charging the batteries when below these conditions may cause damage to the lithium cells and shorten the lifespan of the batteries.

Originally Posted by Davydd

.......................
So, I guess Pleasure-way must think you have to remove your batteries (which means disconnect) and store them inside a climate controlled space....................

That's exactly what PW advises an owner to do.


Snippet from a 2018 PW owners manual:

To extend the life of your lithium batteries it is recommend that the batteries be fully charged and kept above freezing temperatures when in storage. This may involve removing the lithium batteries from the coach and storing them in temperatures above freezing for winter storage.

It seems that newer PW units have a charge line disconnect:


Snippet from a 2018 PW owners manual:

If you are using your coach in freezing temperatures turn the charge line disconnect switch OFF. This will disconnect the engine alternator and solar panels from charging the coach batteries. The coach batteries will continue to discharge and power your coach as normal in conditions up to -20 C or -4 F.

That's bound to confuse folks. Note they specifically said "If you are using your coach" but that would also apply if NOT using the coach if the batteries remain in the vehicle.



If you are using the the coach then presumably the interior of it will be kept warm and the batteries are inside coach with the occupants ............ so their advice to

If you are using your coach in freezing temperatures turn the charge line disconnect switch OFF. ..............

will surely confuse owners.

[Rlum]

Some newer lithium batteries have bluetooth technology built as a bms and safety charging features with temp readings. Last year, I added two 100ah LifeBlue batteries to my bank. They have bluetooth technology. Batteries when down in lower temps will go to sleep(hibernation mode) and not allow themselves to be charged. Kinda of cool with todays new technology!

[Dogman]

I have been reading all of the posts with some great interest. Here is a link to the Coachmen Galleria models and below on the page is a good look at some of the newer Class B Van winter protection padding and materials now being utilized to protect the overall van contents and you.

https://coachmenrv.com/class-b-motorhomes/galleria

[booster]

A couple of things to mention.


When you start adding disconnects you need to be aware the improperly used or connected can sometimes damage things. The most common places for issues appear to be with alternators (the standalone ones not generally when you are using the van stock one) and solar.


With alternators you don't want to shut off the output of the alternator while it is running if it has no other battery on the output. Losing that reference battery for voltage and capacity can cause a spike that can destroy the alternator. You need to shut off the field current first, then output, and you are safe.


Solar panels will be generating voltage and potential current all the time they are getting adequate light, whether the battery is connected or not, which can be an issue because the battery powers the controller and gives it the 12v reference. Drive the van out of the garage into the sun with the coach battery disconnected and you can hit the controller and coach electronics with upwards of 21 volts (open circuit voltage on most current panels) and damage them. Many solar systems are wired directly to the battery before the disconnect to prevent this, but that makes it so you can't have zero load or remove the battery without risking things. A shut off switch on the panels is generally the best way to handle it. We, and others use a switch for solar panels, but use a pullable fuse for the controller to battery wire. A reminder note by that fuse can tell you to make sure the panels are off before you remove it. A similar note can be put on the battery cables so they don't get removed with the panels on.

[booster]

Originally Posted by Rlum

Some newer lithium batteries have bluetooth technology built as a bms and safety charging features with temp readings. Last year, I added two 100ah LifeBlue batteries to my bank. They have bluetooth technology. Batteries when down in lower temps will go to sleep(hibernation mode) and not allow themselves to be charged. Kinda of cool with todays new technology!

IMO, the auto shutoffs are a necessity for batteries as expensive as lithium systems tend do be, as even the best users can make mistakes, and the weather doesn't always care if you are in the van when it turns cold to shut stuff off. Hot, cold, and discharge limit appear to be the big three.



How to handle the restarting of the systems after a shutdown seems to have been a bigger issue for the manufacturers than actually shutting them down. Roadtrek added an AGM battery to be able to restart discharged systems. You have to have some way to override automatic heaters, or put on temporary heaters, to recover from cold or no charge temps, and have a heat source, etc. ARV's solution for low temp shutoff for charging has been to find a place inside to warm up the van, which really isn't all the practical sometimes. I am not aware of if that has changed on there newer stuff or not.


The newer recommendations of no storage at colder then -4*F have complicated things for those in very cold climates that store the van outdoors in the winter, as the only option is to take out the batteries or heat them continuously, which requires a power source and standalone heaters.

[avanti]

Originally Posted by booster

With alternators you don't want to shut off the output of the alternator while it is running if it has no other battery on the output. Losing that reference battery for voltage and capacity can cause a spike that can destroy the alternator. You need to shut off the field current first, then output, and you are safe.

Yes. It is possible to extract a "relay closed" signal from the BlueSea ML-RBS that can be used to control a small "enable" relay. I did this in order to feed a "shut down" signal to my Balmar to protect the alternator just in case someone turned off the coach power while the engine was running.

The signal (yellow wire) is intended to drive the LED on the remote switch, so I was worried about whether it was OK to steal this signal. I wrote BlueSea and they responded promptly with the following:

Thank you for the question. Our Engineering tells me 250 m Amps would be safe for the 7700 ML-RBS. The 7713 ML-RBS would only be able to support 30 m Amps.
Please ask if you have any additional questions.

They are a first-class operation.

[Davydd]

How new is "some newer lithium batteries..."? I've had lithium batteries for 5 years now (December, 2014) with all the bells and whistles protection and have stored outside in Minnesota's winters and that predates Ron's 2016 Ascent. Let's stick with Ron C.'s problem and what to do.

The don't charge below freezing was a given in the lithium battery community probably long before they've been installed in RV's. It seems by Marco Polo's research in P-W manuals they were aware of this from the get go. That means internal temperature of the batteries and not the ambient temperature. In the ability to monitor my battery cell temperatures I have found that batteries in use will tend to be about 10 deg. above ambient. How long, such as in storage, is unknown, but safely one can camp when overnight temperatures go below freezing down to the mid 20's or what most people can tolerate for comfort in a van heated or not. If heated, in a P-W, inside, then the batteries benefit.

Now the absolute -4F issue of freezing batteries. This was generally not known when P-W manufactured the Ascent in 2015 or 2016. In 2016 there was some publishing journals that brought this out, ARV confirmed it to me in the summer of 2016 and the battery assembler, Elite Power Solutions, also confirmed it to me in an email in August, 2016. I think there was some general confusion in translating Fahrenheit to Celsius of -20C in assuming -20F. I can't think of any other reason for people being asleep on the issue as much of the United States, all of Pennsylvania and all of Canada can get below -4F.

Given Marco Polo's research of the 2018 P-W manual:

"To extend the life of your lithium batteries it is recommend that the batteries be fully charged and kept above freezing temperatures when in storage. This may involve removing the lithium batteries from the coach and storing them in temperatures above freezing for winter storage."

They were concerned about freezing temperatures for charging but not for freezing batteries. They still did not acknowledge freezing batteries. In essence they said keep batteries above freezing or manually disconnect them, and move them to a climate controlled area. So for my third time, a battery disconnect switch does not solve the problem for winterizing and storage.

[Rlum]

What kind of solar shut off switch are you referring to? My solar panels are connected directly to controller and from there into battery bank. I usually just disconnect the solar side of panel to controller. You are saying this can/will damage the panels since the load is not removed? How to safely disconnect solar panels without damaging them? Thanks!

[Ron C.]

All such great, knowledgeable responses and information. I really do appreciate everyone’s input. Thanks for re-focusing the discussion Davydd. Some of the conversation is way above my head. Since we will likely be using the RV sporadically over the winter (and therefore not in deep storage), it would seem that what I need to do is install a battery disconnect (for days when using the rig when temps are below freezing, and until the interior of the coach and batteries warm up, at which time I could re-engage the batteries for charge and/or power), but also be wary of the potential need to remove the batteries if there is an extended period of non-use and temps below 4 degrees F.

[Davydd]

You may get through a winter never encountering -4F but if you do encounter chances are it will be a polar vortex like prolonged freeze. Having that disconnect switch may give you false comfort that will come back to bite you in the patootie because it doesn't solve your problem. Also, remember, if you have it, then when on the road, you don't have use of your electrical systems whatsoever. However, if you are using your RV periodically in the winter, and keeping it heated when underway, you don't need a disconnect switch.

Unless you know your electrical system intimately, which you have indicated you don't, then why not perform the ultimate battery disconnect at the terminals whether you then store inside or leave in the van and chance it. If there is not an existing disconnect switch maybe P-W is telling you what I am saying because they have a long history of providing disconnect switches in their vans for lead-acid batteries so would not leave one out by accident.

[booster]

Originally Posted by Rlum

What kind of solar shut off switch are you referring to? My solar panels are connected directly to controller and from there into battery bank. I usually just disconnect the solar side of panel to controller. You are saying this can/will damage the panels since the load is not removed? How to safely disconnect solar panels without damaging them? Thanks!

If I understand correctly, you disconnect the panels before you would take out the battery? If so, you are safe, and you could just replace the disconnecting with and on/off switch between the controller and the panels.


The solar panels themselves can be disconnected without issue or damage to them. It is the other stuff like the controller and van electronics that can get hurt.


You just never want the solar panels connected to the controller if there is no battery in the system and powering the controller.

[GeorgeRa]

I have 2 CBs before and after charge controller and since Booster emphasized the potential issue of damaging the charge controller with battery disconnected while solar panels still being connected (thank you), I placed a warning label as a reminder.

I my case I have the battery disconnect relay near the battery disconnecting all loads and charging sources except solar panels.

If I had Lithium batteries, I would likely add a lot of insulation (perhaps removable for summer time) with an electric heater pad set for low temperatures to prevent damage during these marginally cold days.

[avanti]

Since I park outdoors, I have the solar connected on the battery side of the disconnect. The charge controller and the Trik-L-Start are the only things powered when the switch is off.

[booster]

Originally Posted by avanti

Since I park outdoors, I have the solar connected on the battery side of the disconnect. The charge controller and the Trik-L-Start are the only things powered when the switch is off.

I remember you pull the fuse when you need full disconnect so you can remove battery cables, but forget if you have a switch on the panels or pull the connections at the controller/

[avanti]

Originally Posted by booster

I remember you pull the fuse when you need full disconnect so you can remove battery cables, but forget if you have a switch on the panels or pull the connections at the controller/

The latter. I should have CBs like George, but I didn't understand the issue when I designed the system.

[atlebj]

So we purchased a used 2016 Ascent TS (with Li batteries) this year also and I just winterized it. The manual on page 30 under winterizing states:

" Fully charge your auxiliary coach battery and turn off and remove the red disconnect. The red disconnect is located in the passenger rear storage compartment in the small door above the battery access door."

And on page 33:

"(2) The disconnect in the driver ottoman door is a total battery disconnect used especially for service and winter storage. This battery disconnect will not allow the auxiliary batteries to be charge from the solar panels, converter or the vehicle alternator."

Am I missing something? The 2016 Ascent TS clearly has the switch the OP is referring to (at least mine does) - again, unless I'm missing something...

Atle

[svIntuition]

Randy, If you haven’t been getting helpful information, call the factory next week and ask for Phil Nickel. He will be able to look up the history of your van build and offer advice on how best to care for those batteries. He’s on vacation in Florida now after helping owners at the Sarasota Rally. No one knows more about these vans than Phil.