2016 MBS Sunseeker - Lithium House Battery ?

[baginthewind]

I have no idea what I'm doing :-) so let's start there.

I'm interested in replacing my lead-acid coach battery with lithium.

One of the questions battery sites ask is "Inverter Model". I have no idea. Does anyone else have a suggestion? I can't find it identified in the owners manual.

Perhaps someone can tell me, can I just drop a lithium into the same hole under the stairwell right alongside the chassis lead-acid battery ?

Thanks.

Jay

[Reverse_snowbird]

You probably have a converter, not an inverter.
You'll need to do some research to see if it's feasible for your rig and get some professional advice. It's more complicated on a motorhome.
I do know that you'll probably need a dc-dc converter to protect your rigs alternator from burn out and probably a new converter to charge those batteries.

[Duckogram]

Originally Posted by baginthewind

Perhaps someone can tell me, can I just drop a lithium into the same hole under the stairwell right alongside the chassis lead-acid battery ? …

Lets start with this. You should have two FLA batteries in the stairwell. They are both house batteries unless somebody modified the entire 12V power supply wiring for your MBS. Your chassis battery should be under your feet in front of the drivers seat. Sooooo, the answer to your question is, no.

With that in mind, you can reconsider going LiFePo now that your cost basically just doubled.

Considerations should be: Extent of dry camping and power demands, thickness of wallet, KSA’s to accomplish adding peripherals and cold weather use.

That should scratch the surface for you. Like R-S said, it’s complicated.

[JLeising]

Several of us have done the conversion on our MBS Motorhomes. I did a couple years ago on my 2012. Reported in post #171 in this thread:

https://www.forestriverforums.com/fo...ml#post2286869

Has worked well for me. Since I did the conversion, low cost “battery fuel gauge” type meters came available- I upgraded to the Aili:

https://www.amazon.com/AiLi-Voltmete...tronics&sr=1-2

Also, lithium converters that switch to a “float” voltage of ~13.6 volts after “balancing” the LiFePO4 batteries at 14.6 volts became available. As I never leave the Motorhome plugged in for extended (multi-day) periods, I did not change.

FYI,
Jim

[nvs4602]

Unfortunately it's not that simple. There's no drop in solution for this change over to lithium. That is if you want to do it right. You risk burning up your alternator and ruining your expensive lithium battery or greatly reducing its life span.

I just converted our leprechaun 311fs over to lithium. I did the work myself and built my own 280ah lifepo4 battery. And I spent roughly $1300 doing so. I moved my lifepo4 battery inside the motorhome under the dinette seating to keep it in more of a climate controlled area. Lifepo4 batteries cannot be charged below 40 degrees F. Nor do they like higher temperatures from road or exhaust pipe heat.

[Canadian Eh]

Its not cheap, since on top of the cost of the batteries you need to change the charging system, both from the 110 Volt system and the chassis battery. If you have the opportunity add some more solar also. Contact the maker of the 110V charger, mine was Progressive Dynamics, and see if they make a direct replacement so you can swap out the existing charger to one that will charge your Lithium batteries. Its very easy. Adding the inline DC/DC charge controller should be straight forward but I'm working through some issues with my install. Switching to a Vectron controller to see if that fixes my issues.

[JLeising]

You CAN get away without changing the Converter. The WFCO original converter in my 2012 would have charged the batteries to about 13.6 volts - the recommended "float" voltage for their LiFePO4 batteries by Battleborn. This would be less than 100% charge for the batteries (85 to 90 % I believe) but would work. Two 100 AH Battleborns at 85% would still supply a lot more power than would two lead-acid 100 AH batteries (assuming you follow the advice not to discharge the lead-acids more than 50%). 75% of 200 AH LiFePO4 batteries (to avoid fully discharging them) would yield 150 AH; 50% of 200 AH lead-acid would yield just 100 AH.

You would want to occasionally charge the LiFePO4's to >14.2 volts to balance the cells. This could be done with the dc-to-dc charger while driving. The Renogy 20amp dc-to-dc is on sale at Amazon for <$100:

https://www.amazon.com/Renogy-Batter...ci_mcx_mi&th=1

Disabling the battery interconnect relay (in the BCC center) and replacing it with this dc-to-dc avoids potential alternator risk, and the dc-to-dc can be set to appropriate voltage to equalize the LiFePO4s.

As the four LED battery meter in the motorhome's control center is tied to lead-acid voltage levels, it is not useful with LiFePO4s. The AiLi meter is <$50 on Amazon:

https://www.amazon.com/dp/B07FGFFHC6...efix=aili&th=1

To my mind, the above constitutes a good (not optimal, but quite good) LiFePO4 conversion.

[nvs4602]

Originally Posted by As the four LED battery meter in the motorhome's control center is tied to lead-acid voltage levels, it is not useful with LiFePO4s. The AiLi meter is <$50 on Amazon:

[url

https://www.amazon.com/dp/B07FGFFHC6?ref=nb_sb_ss_w_as-reorder-t1_ypp_rep_k0_1_4&amp=undefined&crid=2XCYJZ1DQ8RHX &sprefix=aili&th=1[/url]

To my mind, the above constitutes a good (not optimal, but quite good) LiFePO4 conversion.

I built a small box out of oak to mount the above mentioned meter. Works good for what I want it for.

[karykatz]

i would find a dealer who is knowledgeable on lithium but you will definitely have to replace the converter