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Topic: Changing to lithium house batteries in a Realm (Read 2734 times) previous topic - next topic - Topic derived from Changing flooded lead...

Changing to lithium house batteries in a Realm

Hi. 

I just changed my 6 4D in my realm to 6 lithium 320aH batteries

I did not do the DC Charger yet, so I disabled the boost function to avoid any alternator interfacing with the house bank. 

Is the DC charger worth it or to only charge house while plugged in or on genset sufficient ?

Thanks

Tom

Re: Re: Changing flooded lead acid batteries to lithium batteries

Reply #1 –
May want to start a new topic. Your coach is way different than a 2004 U270 36WTFS that this post was started for. Completely different coach. This will help other members with your coach learn what you have to help them out.The Dc to Dc charger is to protect your drive engine alternator from being overloaded if starting with low house batteries. Disabling the boost function will not effect your normal Isolator function if your coach is set up like the older coaches. Honestly I wouldn't know. Another reason to start a new post topic.

Re: Re: Changing flooded lead acid batteries to lithium batteries

Reply #2 –
Quote from: Tmyz –
Hi. 

I just changed my 6 4D in my realm to 6 lithium 320aH batteries

I did not do the DC Charger yet, so I disabled the boost function to avoid any alternator interfacing with the house bank. 

Is the DC charger worth it or to only charge house while plugged in or on genset sufficient ?

Thanks

Tom

Your six 4D batteries were ~ 210 A/H each. 1,260 A/H. Replacing them with six 320 A/H brings you to 1,920 A/H. This change is the real issue besides going to Lithium. If you stayed around 1,200 A/H you could have just done drop in. Even at the 1,260 A/H current controls are there to manage not only battery charging but also other loads that could be connected. More than 4 batteries with Lithium is also a bad mix. Most brands say to limit parallel to 4. As you have 6 batteries you want at least 10 amps charging for each 100 A/H capacity plus for other connected loads such as that fridge or f running the heat while driving. If your plan is to run an AC on inverter while driving add another 100 amps for that. Even going with the Sterling 120-amp DC-DC charger you really need 2 for 240 amps. Not following this thread. Are you also adding solar? Two things to consider with DC-DC chargers. When they need to boost voltage, they will draw more current than they output.  The wattage formula will rule. They are also, like most battery chargers are designed for charging batteries. As batteries charge, current and power will drop. Supporting large loads charging profiles no longer in play and these devices just become heaters especially when they are undersized. While I can see running AC's from battery while camped to avoid the generator during quiet or sleep hours, I do not see the real benefit to running them from engine alternator-battery. To do it right you need to look at something like this.

https://1drv.ms/i/c/9b02084a888884a6/IQCv9FHMBG4JRItRyJeK0acUAf4BEOWPsrGD8pxgrgOfFx8?e=Bq4IaV

Re: Re: Changing flooded lead acid batteries to lithium batteries

Reply #3 –
As said above, does your manufacture recommend more then 4 batteries wire together in parallel?  In my 2014 IH45 I have both an isolator and the smart boost switch.  I am not sure your coach has an isolator but if you do you will need to also disconnect the house batteries from it. Your coach only has an alternator that is rated at 270-240 amps. I do not know what the duty rating of the alternator is.  On my coach sitting running off the batteries, the coach and inverters pull around 20-25 amps from the batteries.  If you do not install at least a 30 amp B2B charger, you will not be keeping up with the loads unless you are running the generator.

Not sure if you have done already, have you changed the setting on your inverter/chargers to charge the way the manufacture has in it's specifications?

I think Michelle needs to change the subject to add that this discussion is about a Realm.

Re: Changing flooded lead acid batteries to lithium batteries

Reply #4 –
Thanks for moving this topic to a new thread.  My deciding to to go with lithium was really bang for the buck.  Battery cost was about the same as the original 4D which started swelling and gassing after 3 years as I'm in vegas heat.  At least in part I think that is to blame. I don't plan on adding solar but I certainly may if I start boondockinh more. Right now our primary caning is lake and plugged in but staying outside the plugs and not having to run genset hours daily to keep batteries topped will be a bonus.  This is all new to me, so just looking for advice and best practices for this upgrade.  Thanks again for the replies.

Re: Re: Changing flooded lead acid batteries to lithium batteries

Reply #5 –
My coach came with 6. 4ds.  I had a boost switch installed previously that allowed me to run full time in boost mode charging all batteries while coach running and chassis batteries while on shore power.  At the advice of installer, I switched that to off knowing I won't be charging house bank while engine running. I'm trying to keep the alternator out of the equation until I decide on proper alternator and dc dc charger.

Re: Changing to lithium house batteries in a Realm

Reply #7 –
Quote from: turbojack –
As said above, does your manufacture recommend more then 4 batteries wire together in parallel?  In my 2014 IH45 I have both an isolator and the smart boost switch.  I am not sure your coach has an isolator but if you do you will need to also disconnect the house batteries from it. Your coach only has an alternator that is rated at 270-240 amps. I do not know what the duty rating of the alternator is.  On my coach sitting running off the batteries, the coach and inverters pull around 20-25 amps from the batteries.  If you do not install at least a 30 amp B2B charger, you will not be keeping up with the loads unless you are running the generator.

Not sure if you have done already, have you changed the setting on your inverter/chargers to charge the way the manufacture has in it's specifications?

I think Michelle needs to change the subject to add that this discussion is about a Realm.


Based on what I'm seeing in the immediate feedback I'm getting is install the proper alternator charging systems.   

Re: Changing to lithium house batteries in a Realm

Reply #8 –
Quote from: Tmyz –
Based on what I'm seeing in the immediate feedback I'm getting is install the proper alternator charging systems.
You can wait on the B2B and see if you can get by without it.  You do need to make sure if you're coach has an isolator that you disconnect the house batteries from it.

Re: Changing to lithium house batteries in a Realm

Reply #9 –
Would this be considered the isolator?

Re: Changing to lithium house batteries in a Realm

Reply #11 –
In my IH45  the isolator is mounted on the right upper side of the engine bay. I have looked in the engine bay of many of the newer coach's but never paid any attention as to if it had one or where it was located.

The smart battery switch like you posted the picture of keep the house and coach batteries tied together until the voltage got down to I believe 12.7volts then it would disconnect to cut out the connection between the coach and house batteries.  This switch was also used to keep the coach batteries up. With you having the switch off, the only way the coach batteries would get charged if from the alternator running or you turning the battery switch back on.  I am not sure if the coach batteries have any parasite draws on them to pull them down when coach is not running. 

Re: Changing to lithium house batteries in a Realm

Reply #13 –
Quote from: Tmyz –
Would this be considered the isolator?
I have this same auto boost switch in a 2013 Nimbus. Learned about it while diagnosing it as failed closed. In our coach you'd have to switch this to "man off" to keep the new house batteries separate from the alternator circuit.

Re: Changing to lithium house batteries in a Realm

Reply #14 –
Quote from: Tmyz –
Hi. 

I just changed my 6 4D in my realm to 6 lithium 320aH batteries

I did not do the DC Charger yet, so I disabled the boost function to avoid any alternator interfacing with the house bank. 

Is the DC charger worth it or to only charge house while plugged in or on genset sufficient ?

Thanks

Tom

Balancing 6 X LiFePO4's in parallel can be tricky.  I think I'd separate those into two banks of three.  With that much capacity, I would want to leverage all possible charging sources, so yes I would put in the DC-DC  converter or an alternator setup with over-temperature protection.

Re: Changing to lithium house batteries in a Realm

Reply #15 –
I just spoke to Foretravel about the inverter codes.  They are not happy with me and think that it's best just to run with the original equipment.  Just sharing thier comments.  I'll give feedback as I go down this lithium road.  I really thought it was a great upgrade for longevity in battery life and less dependence on genny/shore. 

Re: Changing to lithium house batteries in a Realm

Reply #16 –
Quote from: Tmyz –
I just spoke to Foretravel about the inverter codes.  They are not happy with me and think that it's best just to run with the original equipment.  Just sharing thier comments.  I'll give feedback as I go down this lithium road.  I really thought it was a great upgrade for longevity in battery life and less dependence on genny/shore.

I just went through the wiring diagrams for a 2024 Realm and it does NOT have a battery isolator, only a Boost VSR Relay. With you manually turning this switch off then you are disconnecting the alternator from charging the house batteries, thus keeping from burning up the alternator due to overload.  Just make sure you did not leave the switch still in the auto off mode, I have not researched if that is a possibility. The one problem that this causes is your house batteries are not going to be charged going down the road and your coach batteries are not going to be charged when plugged into shore power or running the generator. If I was you I would get a B2B charger that goes both ways, That way the coach batteries will stay charged and the house batteries will get charged or will stay at the same SOC.

Not sure what you mean by inverter codes? Is your invertor throwing codes?  I agree with this upgrade, just need to add B2B and verify with the manufacture of your batteries that six in parallel is OK.

Who at Foretravel was not happy with what you did?

Re: Changing to lithium house batteries in a Realm

Reply #17 –
I'm curious about that also.

Re: Changing to lithium house batteries in a Realm

Reply #18 –
Guys name was Eddie.  Very nice but wasn't being talked into my theory. 

The code referenced was the password for the panel to change settings

The set up is on a bus bar, not traditional link link parallel so tech does not make sense to put on 2 banks of 3

Re: Changing to lithium house batteries in a Realm

Reply #19 –
Also as info my coach is a 2022, picked up in late 2021. 28,000 miles.  Coach 9133