Li-Ion Drop in Battery Upgrade

MSR

Member
I changed out my OEM 6V AGMs for a pair of 12V, 100A BattleBorn LiFePO4 GC2 Deep Cycle batteries with built in BMS. Everything fitted well in the bank with some minor adjustments!


I haven’t changed the solar or inverters. Hopefully, this will work for me! I don’t do dry docking. Usually there is power or I run the generator when I need something extra. I plan to keep the RV plugged in when parked at home!
 

autostaretx

Erratic Member
If you're planning long down-times, Lithiums don't like to be fully charged when not in use.
50 to 80% seems better. (if i recall correctly).

Dig through the lithium threads.

--dick
 

irvingj

2015 RT SS Agile (3.0L)
I believe you're right, Dick, it's the same for RC stuff: for storage, NOT fully charged is best for LI batteries. Some LI battery chargers even have a setting for that!
 

msmolow

2019 Unity CB / 2018 Chas
MSR, if you are always on shore power or generator was there a reason you elected for the significantly more expensive Lithium batteries?
 

MSR

Member
there was an occasional overnight stay when I would not have shore power, the OEM batteries would just go down to 11v always!!! Hopefully, this is going to be better. I have to my charging modules thought. I am too green with that stuff to figure it out. I hate taking the RV to a shop. Such a chore and who’s around where we live army any good !!
 

MSR

Member
It’s a 2018 Unity. They fit in the bay but you have to remove a couple of guides they install to secure the OEM batteries. Also, these are in parallel configuration. So you 2 similar battery connecting cables, 2 feet length.
 

Klipstr

2018 Wonder FTB
So you have the factory solar system? I think I would replace at least the charge controller with a Victron 100/30 so you can setup the charging profile to fit your new batteries. Your alternator/generator charging won't be quite correct but the BMS within the batteries seems to do a reasonable job. Anecdotally based on Scarecrow's system (he has the Victron stuff and the Battleborn batteries) which seems to keep his batteries in tip top shape. The nice thing about the solar charging is when you roll into camp in the afternoon and turn the engine off the solar kicks in to finish the charging cycle no matter where it is at in that cycle. It turns out the late stages of the charging cycle are the most complicated and essential so it's good to have a very smart charge controller working the problem for you.
 

TampaSteve

2018/2019 Unity CB
I installed 2 12V Battleborns. I did put in the better Magnum remote control ME-RC50 so I could have more profile choices and a Victron 712 to monitor. So far the whole thing seems fine, with the caveat that solar, alternator, and the Magnum charger all are bit quirky on LiFePO4 and often don't charge the batteries the last 10%. That's not a huge deal but I think I will go ahead and install the SmartSolar MPPT 100/50 Charge Controller before next summer. The reason for going 50 amps is it's just a little bit more and who knows someday when the flex panels fail I may pile a lot more cells on the roof.

With a better solar charger the Magnum inverter and relay under the seat can wait probably a long time for an upgrade like when they fail.

There are other reasons besides more juice for upgrading to LiFePO4. Lower weight, super long warranty, no gassing or acid, and the built in BMS means if I do something stupid like leave the van unplugged for a few weeks with the switch on I don't return to ruined batteries.
 

msmolow

2019 Unity CB / 2018 Chas
I live in Northeastern Pennsylvania where winter temps often drop into the teens and below. I store my Unity outside in a lot a couple of miles from my house.
Last winter I brought it home every 2 1/2 weeks to recharge the coach batteries. This winter I'm depending on this summer's solar panel install.
My understanding is that Lithium's should not be charged in those temps so if I want them I'll need to move.
 

woundedpig

2018 Unity MB
My understanding is that Lithium's should not be charged in those temps so if I want them I'll need to move.
Battleborn’s can be discharged at temps less than freezing but not charged. However, they have little to no voltage “leak,” so if they are charged and disconnected, they can easily last the winter without risk of damage. The battery disconnect in the stepwell is not enough to prevent parasitic draw, so either the negative cable can be disconnected or a separate disconnect can be installed in the positive line leading from the house bank to the inverter. There is room for one of the HD Blue Sea switches. I did the latter and there is no discharge whatsoever per a Victron battery monitor, other than the tiny milliamp consumption by the Victron monitor itself, which could also be powered down. Some people remove their lithium batteries and store indoors during the winter, but according to BB, this is not necessary. They say just to charge and disconnect. Still, if you live in the frozen north and will not be using the RV for a number of months and have to store in unheated space, removing the batteries will provide some extra peace of mind, given the batteries’ $900+/each cost.
 

Gamma1966

2013 Chassis /14 Unity MB
Wow. That’s very insightful Klipstr. Is this a DIY for electrical naïveté like me?

I presume you are talking about this unit on Amazon?
I recently bought a Vicrton 100/30 MPPT charger from AMSolar out of oregon.
There price for the unit on their Amazon web store is competitive, but more importantly if you need tech support on install / configuration / or trouble shooting and install I have found them to be an excellent vendor. They are very responsive to e-mail request for support and will also answer the phone, unlike many other Amazon store vendors for the Victron Products.
 

SSTraveler

2014 LTV Unity Murphy Bed
Wow. That’s very insightful Klipstr. Is this a DIY for electrical naïveté like me?

I presume you are talking about this unit on Amazon?
I don't know what your level of DIY capability is but you should be able to change out the GoPower for the Victron Smart controller 100/30. You'll need to cover your panels so they stop producing power before disconnecting the battery or you can damage the controller. The solar panels need a load like batteries to discharge its power. The solar controller can be damaged if there is no load and the solar panels are discharging to it alone. With that in mind you may want to add circuit breakers (in line on the postitive cables) on your install of the Victron Smart controller to make it easy to disconnect your solar system as well. You can get the circuit breakers from Amazon as well, https://www.amazon.com/ZOOKOTO-Circ...30a+circuit+breaker+12v&qid=1571223459&sr=8-9. I think Leisure just uses fuses in their installs and I don't think they are easily accessible as circuit breakers can be made. Here is a picture of my install a couple of summers ago. I didn't get the solar option I did a complete install as others have, if you do an advanced search you will be able to see a lot of helpful information.

What is your plan on maintaining the chassis battery (AGM) while in storage? Disconnecting as well using the disconnect plug at the drivers accelerator pedal?
 

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harrysalit

2019 Wonder FTB
In my Wonder, LTV has a 30 amp in line fuse, behind the batteries for incoming solar.
To reach the fuse the batteries must be removed! Two 12 volt lead acid.
And the main fuse block for inverter, generator, solar, etc are also located behind the batteries!
Really clever engineering!
 

msmolow

2019 Unity CB / 2018 Chas
Harry, I believe LTV's fuse behind the battery is after the charge controller, so pulling that will not disconnect the panels from the controller.


I added a solar panel disconnect switch as part of my self-install for the reasons SSTraveler listed. The switch is in addition to a fuse between the controller and the battery bank.
Attached is a re-post of what I did. Page 21 shows the switch.
 

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I live in Northeastern Pennsylvania where winter temps often drop into the teens and below. I store my Unity outside in a lot a couple of miles from my house.
Last winter I brought it home every 2 1/2 weeks to recharge the coach batteries. This winter I'm depending on this summer's solar panel install.
My understanding is that Lithium's should not be charged in those temps so if I want them I'll need to move.
I just installed 2 X 100Ah Relion RB100-LT units in my Navion. Had to trim the original battery bay a bit to get them to fit, as they are GR31 sized and were longer than the factory installed GR24 FLAs. They're chargeable down to 4F/-20C, as they "borrow" some of the charging current to internally self-heat the battery enough, that it can accept a higher rate of charge below freezing. Not cheap, but they solve the charging below freezing problem that most LiFePO4 batteries don't. Also I dealt with their sales/support folks, and they were extremely helpful, answered all my questions and concerns.
All in all, a good upgrade option for we who live in colder climates. I have already added a 3rd 100W Zamp panel to bring my charge capacity to 300W. The Zamp charge controller has both LiFePO4/AGM charge profiles to complete the charging that the alternator/generator/shore power might not.
 

TampaSteve

2018/2019 Unity CB
The solar controller panel is located in the most idiotic location imaginable in my van in the overhead front cabinet. You need a flashlight to see it. So I plan to replace that with a disconnect switch, and then mount the new solar controller in the compartment with my inverter, and finally pigtail that to the wires in the battery compartment next to it - that now run from the new disconnect switch. (And also put in a breaker instead of a fuse).

That way I end up with the solar controller mounted close to the batteries as its supposed to be, and a vertical mounting plane as required, and I have a solar disconnect in the overhead cabinet where the old controller used to be.

I can't remember who posted that configuration, but I liked the idea and plan to go that way.
 

harrysalit

2019 Wonder FTB
Yes, the fuse is behind the batteries, the controller is in a overhead compartment in the kitchen! Another ridiculous location.
If you want to turn off the solar going to the batteries, remove the controller and disconnect wires there or remove batteries to access fuse! Not great if need to shut off in an emergency!



QUOTE=msmolow;815504]Harry, I believe LTV's fuse behind the battery is after the charge controller, so pulling that will not disconnect the panels from the controller
 

Klipstr

2018 Wonder FTB
All correct with a few minor notes:

Covering the panels is not that important IMHO. If you disconnect the battery side of the charge controller by removing the fuse there will be no load on the charge controller so no current will flow to the controller or beyond. And besides you don't care about that controller anymore anyway.

Yes, it is DIY. Not really tricky if you have some basic wiring skills and can perceive what's happening with the overall system. Yes, go bigger if you plan on replacing/adding more panels later. The 100/50 isn't that much more. For Wonder owners: you don't have room, really, for more than four panels so the 100/30 is fine.

Yes, add circuit breakers per SS between the panels and the charge controller (eliminating the need? to cover the panels) and between the charge controller and the batteries. Make sure they are both turned off. The connection between the charge controller and the batteries obviously provides power to the charge controller so it can boot up and find its mind! After I wire one up I turn on the breaker to the batteries and let the controller boot and then flip the breaker for the panels and watch what happens via the Victron Bluetooth app on my phone. Instant gratification as you watch the amps run off the roof into your batteries!

Tampa mentioned putting the controller in the inverter bay and wiring it to the batteries in the battery bay. Not really necessary, although technically correct. You can wire the charge controller directly to the inverter positive and negative instead. Shorter run and the wiring between the inverter and the batteries is heavy duty. Your choice. I've taken to wiring to the inverter as it's simply simpler!

You might as well add the Victron battery monitor too. Another $200 or so but worth it. In my Unity I had upgraded the Magnum remote to the more functional one but still think the Victron is better. That said, the more functional Magnum will allow you to tweak your converter/charger settings within the Magnum inverter to better support charging your lithium batteries so maybe worth it too.

Echo the concerns about the interaction and incomplete charging by all systems working on the problem. I think the alternator is the weak link as there isn't any way to tweak its behavior. There is a thread in this forum discussing a DC to DC charge controller that is programmable. I think if I were to spend the dough on a lithium system I'd install one of these too. For those of you with lead acid batteries I don't think you need to over worry that. If you're like me, and I know I am, I roll into camp in the mid to late afternoon and the solar completes that last little bit of charging before the sun sets.

One last thing for the OP: when you replace the charge controller you will want to rewire your panels from pure parallel to a series/parallel configuration. You can do that on the roof with the Y connectors. When you do this you raise the voltage coming down to the charge controller from12V (nominal) to 24V. This results in less voltage drop (as far as the system is concerned) and helps to overcome the fact that the wire size from the roof to the battery compartment is not really optimal. Some folks have rewired the panels to the battery/inverter bay. I don't think that's really necessary if you rewire the panels. That said, if you want to create the perfect install that's probably what should be done. But the gain will be nominal and always remember that perfect can be the enemy of good.

I'm toying with the idea of writing (with everyone's help) and comprehensive/consolidated topic covering all of this. We have collected a ton of wisdom on the issue of the perfect solar design/implementation but it is scattered across numerous topics and thus hard to find/read/digest.

And, as always, if you can catch me in Show Low or Rio Verde I'm happy to help you out with this stuff in my driveway!
 

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