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11-14-2021, 06:37 PM
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#1
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Senior Member
Monaco Owners Club RV Trip Wizard
Join Date: Sep 2021
Location: Airdrie, AB
Posts: 510
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Lithium adoption strategies for older coach
My '97 Monaco Dynasty is in need of new batteries.
I would like to invest in a set of 280ah or 300ah LiFePo4 House batteries, most likely assemble them myself from imported cells, etc.
My coach has the original electrical equipment, all in good working order:
- Freedom Model 20 Inverter/Converter (2000w, 100A 3-stage battery charger, no Lithium charge profile)
- 200A Leece Neville Alternator
- 160A Solar Controller (no Lithium charge profile)
Being on a tight budget I would only do this if I can get away with minimal changes to the existing converter, etc.
Since the converter and solar controller lack Lithium charge profiles, I am thinking of two possible configurations that would allow me to keep most of my existing equipment and still enjoy Lithium house batteries.
Configuration #1
1. Use the Gel charge profile settings on the converter and solar controller - Either 14.1 or 14.4v acceptance voltage, w/ 13.8v float charge and 14.1 or 14.4 equalization voltage.
2. Use a 60A DC-DC charger between the chassis battery and the house battery to limit load on the alternator, or disconnect the House batteries from the alternator altogether.
Is it feasible to use the Gel charge settings with Lithium batteries? The top voltage seems alright, I'd be fine with charging to 85-95% of max anyway.
Configuration #2
1. Connect the converter, solar charger, and alternator exclusively to the Chassis battery.
2. Connect the Lithium House batteries to the Chassis battery via the 60A DC-DC charger.
This way shore power, alternator, generator, and solar all charge the chassis battery, and then power is regulated to the Lithium battery at 60A from there. This seems really simple setup-wise, I may lose some efficiencies by putting all charging through the DC-DC charger, but it seems like a reasonable tradeoff.
So what am I missing?
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11-15-2021, 04:35 AM
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#2
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Senior Member
Join Date: Feb 2013
Posts: 1,216
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Without trying to sound negative on lithium, I would skip it. I have them in my new coach but would gladly take back the price of the option and just put in good AGM GC batteries.
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11-15-2021, 07:45 AM
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#3
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Senior Member
Monaco Owners Club RV Trip Wizard
Join Date: Sep 2021
Location: Airdrie, AB
Posts: 510
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Quote:
Originally Posted by az99
Without trying to sound negative on lithium, I would skip it. I have them in my new coach but would gladly take back the price of the option and just put in good AGM GC batteries.
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And why is that? It's pretty clear that Lithium is cheaper and better performing than the alternatives, at least in terms of total cost per AH during the actual lifecycle of the battery.
We have a residential fridge and like to boondock, so would like to be able to run for a couple of nights without power. Of course, with the 7.5K genny out front not much of an issue to fire it up for a couple hours to charge if needed. I've just never been a "generator head" so that kind of rubs me the wrong way. I agree though, if there's no reasonable path forward without replacing the converter/alternator, etc. it won't be cost effective.
Quote:
Originally Posted by RoadTrip2084
Configuration #2
1. Connect the converter, solar charger, and alternator exclusively to the Chassis battery.
2. Connect the Lithium House batteries to the Chassis battery via the 60A DC-DC charger.
This way shore power, alternator, generator, and solar all charge the chassis battery, and then power is regulated to the Lithium battery at 60A from there. This seems really simple setup-wise, I may lose some efficiencies by putting all charging through the DC-DC charger, but it seems like a reasonable tradeoff.
So what am I missing?
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So I've realized one big thing I'm missing with config #2 is an inverter that can run off the Lithium house bank.
So I would need to purchase a new inverter at least to run off the House batteries in this setup.
Still looking for input and ideally from someone who's used Lithium with older converters, etc.
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11-15-2021, 07:48 AM
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#4
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Senior Member
Join Date: May 2017
Location: Itinerant
Posts: 755
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Quote:
Originally Posted by az99
Without trying to sound negative on lithium, I would skip it. I have them in my new coach but would gladly take back the price of the option and just put in good AGM GC batteries.
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Why...did you fall for the hype that everyone talks about but realized that the benefits didn't fit your style of camping and AGM would do everything you wanted without the extra cost?
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11-15-2021, 08:08 AM
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#5
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Community Moderator
Join Date: Aug 2011
Posts: 6,182
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I would think config #1 would work, just disconnect house batteries from chassis. You probably have a big solenoid that joins the two banks together….just disable the wire that energizes the solenoid. You may be able to retain the wire going to the “boost” switch on dash, so that you could join the banks together (engine not running) to give the chassis batteries a “boost charge” should they ever discharge too low to start the engine.
Since you have solar, I would think you really wouldn’t need alternator charging.
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11-15-2021, 08:39 AM
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#6
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Senior Member
Join Date: Jul 2014
Posts: 35,317
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If you have a large house charger, option #2 will limit that to 60 amps or less.
One big benefit of Lithium is fast re-charging.
On that rainy weekend, when you need the generator, you want all the amps you got and short run times.
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11-15-2021, 08:59 AM
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#7
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Senior Member
Join Date: Sep 2020
Location: Shrewsbury
Posts: 276
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I agree with pasdad1. I think config #1 should work fine. DC to DC charger only if you think you'll need to charge from the alternator.
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11-15-2021, 09:23 AM
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#8
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Senior Member
Monaco Owners Club RV Trip Wizard
Join Date: Sep 2021
Location: Airdrie, AB
Posts: 510
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Quote:
Originally Posted by twinboat
If you have a large house charger, option #2 will limit that to 60 amps or less.
One big benefit of Lithium is fast re-charging.
On that rainy weekend, when you need the generator, you want all the amps you got and short run times.
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Well my converter will charge at 100A max, so I figured 60A out on the DC-DC would be close to 70A in, so not that far off the mark.
Are there potential issues with not charging the Lithium to 100%? BMS won't be able to top-balance the cells, for example?
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11-15-2021, 05:57 PM
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#9
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Senior Member
Join Date: Sep 2020
Posts: 624
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Quote:
Originally Posted by Itinerant1
Why...did you fall for the hype that everyone talks about but realized that the benefits didn't fit your style of camping and AGM would do everything you wanted without the extra cost?
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Seems like a 200Ah AGM and 100Ah LiFePO4 are the same price these days.
__________________
2015 Chevy 2500HD 6.0 4x4 CC SB
2021 Salem Hemisphere 290RL
Andersen Ultimate
1200W Solar > 412 aH LiFePO4 > Victron MultiPlus II
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11-15-2021, 06:19 PM
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#10
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Senior Member
Join Date: Feb 2019
Location: Walton, KY
Posts: 351
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There is no issue not charging the lithium battery to 100% matter of fact it will prolong its life if you don’t.
I would not build a battery smaller than 400Ah.
Keep in mind that you cannot charge your battery below freezing temps. Having a BMS that prevents that is great but you still can’t charge … so either a heating pad (that is what I have) or a heated space for the installation location is something you need to think about.
Have a look if your existing charger has a charge set up called “custom”. Here you could set the float, absorption and max charge voltage. This is what I did on my older Xantrex inverter.
Have fun
Jörg
__________________
2006 Alpine 34 FDDS
2013 Honda CRV
Blue Ox, Patriot
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11-15-2021, 06:35 PM
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#11
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Senior Member
Join Date: Sep 2020
Posts: 624
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Quote:
Originally Posted by RoadTrip2084
My '97 Monaco Dynasty is in need of new batteries.
I would like to invest in a set of 280ah or 300ah LiFePo4 House batteries, most likely assemble them myself from imported cells, etc.
My coach has the original electrical equipment, all in good working order:
- Freedom Model 20 Inverter/Converter (2000w, 100A 3-stage battery charger, no Lithium charge profile)
- 200A Leece Neville Alternator
- 160A Solar Controller (no Lithium charge profile)
Being on a tight budget I would only do this if I can get away with minimal changes to the existing converter, etc.
Since the converter and solar controller lack Lithium charge profiles, I am thinking of two possible configurations that would allow me to keep most of my existing equipment and still enjoy Lithium house batteries.
Configuration #1
1. Use the Gel charge profile settings on the converter and solar controller - Either 14.1 or 14.4v acceptance voltage, w/ 13.8v float charge and 14.1 or 14.4 equalization voltage.
2. Use a 60A DC-DC charger between the chassis battery and the house battery to limit load on the alternator, or disconnect the House batteries from the alternator altogether.
Is it feasible to use the Gel charge settings with Lithium batteries? The top voltage seems alright, I'd be fine with charging to 85-95% of max anyway.
Configuration #2
1. Connect the converter, solar charger, and alternator exclusively to the Chassis battery.
2. Connect the Lithium House batteries to the Chassis battery via the 60A DC-DC charger.
This way shore power, alternator, generator, and solar all charge the chassis battery, and then power is regulated to the Lithium battery at 60A from there. This seems really simple setup-wise, I may lose some efficiencies by putting all charging through the DC-DC charger, but it seems like a reasonable tradeoff.
So what am I missing?
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That is a nice inverter/charger. I would set the charge profile to the 12V wet cell cool temperature: 14.3V Bulk (they refer to it as acceptance) and 13.4V float. You don't want the Gel profiles because 13.8 float is way too high for LiFePO4.
Which remote do you have? If you have the Link 2000R, you are all set. The Link 2000R regulates the alternator output for you. If you don't have the 2000R, then maybe you can find one (I could not). Otherwise, just use a 60A DC-DC charger like you have in #1.
__________________
2015 Chevy 2500HD 6.0 4x4 CC SB
2021 Salem Hemisphere 290RL
Andersen Ultimate
1200W Solar > 412 aH LiFePO4 > Victron MultiPlus II
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11-15-2021, 09:05 PM
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#12
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Senior Member
Alpine Owners Club
Join Date: Nov 2015
Location: Lake Havasu City, AZ
Posts: 3,004
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Quote:
Originally Posted by RoadTrip2084
My '97 Monaco Dynasty is in need of new batteries.
I would like to invest in a set of 280ah or 300ah LiFePo4 House batteries, most likely assemble them myself from imported cells, etc.
My coach has the original electrical equipment, all in good working order:
- Freedom Model 20 Inverter/Converter (2000w, 100A 3-stage battery charger, no Lithium charge profile)
- 200A Leece Neville Alternator
- 160A Solar Controller (no Lithium charge profile)
Being on a tight budget I would only do this if I can get away with minimal changes to the existing converter, etc.
Since the converter and solar controller lack Lithium charge profiles, I am thinking of two possible configurations that would allow me to keep most of my existing equipment and still enjoy Lithium house batteries.
Configuration #1
1. Use the Gel charge profile settings on the converter and solar controller - Either 14.1 or 14.4v acceptance voltage, w/ 13.8v float charge and 14.1 or 14.4 equalization voltage.
2. Use a 60A DC-DC charger between the chassis battery and the house battery to limit load on the alternator, or disconnect the House batteries from the alternator altogether.
Is it feasible to use the Gel charge settings with Lithium batteries? The top voltage seems alright, I'd be fine with charging to 85-95% of max anyway.
Configuration #2
1. Connect the converter, solar charger, and alternator exclusively to the Chassis battery.
2. Connect the Lithium House batteries to the Chassis battery via the 60A DC-DC charger.
This way shore power, alternator, generator, and solar all charge the chassis battery, and then power is regulated to the Lithium battery at 60A from there. This seems really simple setup-wise, I may lose some efficiencies by putting all charging through the DC-DC charger, but it seems like a reasonable tradeoff.
So what am I missing?
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Configuration #1 will work just fine. Choose the AGM2 or Gel profile that will charge at 14.4 and the internal LiFePO4 BMS will take over when the batteries are fully charged.
I ran this way for almost a year with a freedom 458-20 which is very similar.
The DC-DC will make a big difference as the charger is on the smaller side in the Freedom unit, but will get the job done.
As far as the solar controller, if it doesn't have an AGM/Gel profile then while it will still work I would look at replacing it with a new MPPT controller that does have a Lithium profile and this can be done for around $200 based on the size of your solar array. This is not that tough make sure you take advice from Lithium users, we've been there
__________________
Paul & Jean
2001 Alpine 36FDDS (74291)-3900W Solar, 13,440Wh (525Ah @24V) LiFePO4
2019 Jeep Grand Cherokee Trailhawk (Hemi)
2006 Alpenlite 32RL - Sold
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11-16-2021, 05:11 AM
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#13
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Senior Member
Join Date: Feb 2013
Posts: 1,216
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Quote:
Originally Posted by Itinerant1
Why...did you fall for the hype that everyone talks about but realized that the benefits didn't fit your style of camping and AGM would do everything you wanted without the extra cost?
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I did not fall for any hype. The new coach I bought had it already installed. For the cost and complexity the AGM's are the better choice for me. If I could have the cost of the $9000 option back, I would do it in a second.
I am sure lithium is a great solution for some but some are just spending $ with little gain.
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11-16-2021, 05:27 AM
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#14
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Senior Member
Alpine Owners Club
Join Date: Nov 2015
Location: Lake Havasu City, AZ
Posts: 3,004
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Quote:
Originally Posted by az99
I did not fall for any hype. The new coach I bought had it already installed. For the cost and complexity the AGM's are the better choice for me. If I could have the cost of the $9000 option back, I would do it in a second.
I am sure lithium is a great solution for some but some are just spending $ with little gain.
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Exactly what did you get for that $9K
__________________
Paul & Jean
2001 Alpine 36FDDS (74291)-3900W Solar, 13,440Wh (525Ah @24V) LiFePO4
2019 Jeep Grand Cherokee Trailhawk (Hemi)
2006 Alpenlite 32RL - Sold
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