Another Solar Thread

[Lamokadave]

Short version of a longer story.
New to us 2021 XG32
Had some visible corrosion in battery compartment, plus Thanks to these forums and particularly Judge, became aware that the BIM in the battery compartment might be incorrectly wired. (yes it was).
Experienced the adventure of removing the 4 -6 volts (required removing the top step completely) and discovered that the batteries were all dry.
2 are shot and 2 barely usable for the short term.
So we're now shopping replacements and decide to make life easier and eliminate to need to repeat this adventure considering ongoing maintenance.
Living in the SW we prefer to boondock when camping locally ie 150 mile radius
and in our prior Lance TT did that easily on 210A LA batteries and 300w solar.

Now the residential fridge and macerator toilet becomes a game changer.

WE may have jumped a bit too fast but we ordered 3- 100A Renogy batteries with the blue tooth self report feature. The specs they show looked reasonable
and they will fit in the existing compartment . One spec they don't show ( I called them the next day),and has me a bit concerned is the surge discharge rate. The BMS will only allow a 120% short burst before shutting down.
My concern here is we researched and see the Genny requires approx 450CCA
at 0 Degrees F. We'll likely never experience that, but I'm hoping the batteries can handle the routine genny startups. If not, I'm assuming I can use the emergency start feature and link in the chassis batteries.

That was a bit long winded but it leads me to today's questions.
I see several lithium pioneers have designed their systems replacing the BIM 160 with the lithium compatible 225. They don't seem to install a Dc to DC charger. I'm curious why you took that route. My batteries ea have a 50a max recharge rate and in parallel would be 150a draw on the alternator . That seems like a potential problem. If I go the DC to DC charger path, is there any need or advantage to upgrading the BIM? I'm also not seeing a need to upgrade to a lithium converter.
I currently have 200w solar on the roof and plan to add the ability to use portable solar aka solar on the side the chase the sun, plus the probable alternator driven charger. Why worry about the batteries sitting at converter float voltages?

[DavidEM]

All good, intelligent questions. Here are some answers hopefully:

Yes the BMS will allow 1.2C per battery for a few seconds but with three of them I doubt if the generator draws a starting current of 360 amps in any normal condition. My 4,000 watt Onan generator's starting circuit is protected by a 100 breaker and has never tripped.

There are two reasons to install an upgraded Li-BIM 225. One is that the BIM 160 connects at 13+/12.5- volts (coach/chassis or visa versa) and that may not be optimum for Li batteries. The other is that the Li-BIM 225 cycles off and on every 15 minutes to limit overloading the chassis alternator.

Your Li batteries can charge at up to 50 amps each but that doesn't mean that they will. The Li batteries SOC and voltage drop in the wiring to the chassis alternator will limit that current. You only need to worry when the Li batteries are nearly depleted and you run the chassis engine.

I have been following this issue for a year or so in preparation for moving to Li batteries and the very few reports of actual measured current from the chassis alternator indicate that with 200 Ahs of Li batteries at 50% SOC the chassis alternator will supply 40 amps. That will not overload the typical RV chassis alternator. Your 300 Ahs of Li batteries will drawt more current, but not linearly like 60 amps, maybe 50 which should be ok for your alternator.

So..... I would just install your 300 Ahs of lithium batteries and measure the current from the alternator using a clamp on DC ammeter with the batteries well discharged. Anything of 50A or below I wouldn't worry about. You can also measure the chassis' alternator's case temp with an IR gun. 200 F would be ok.

And finally you can't install a DC to DC charger and keep the BIM. You can't have both as the DC to DC charger is one way as it effectively has a diode and won't go the other way. The BIM requires a two way circuit. So you will lose the aux start capability unless you wire a separate starting relay which won't be that expensive or difficult.

Sorry to make this so long, but lots of interesting issues to deal with.

David

[Lamokadave]

I really appreciate your input David. From reading earlier threads I recall you challenging the wisdom of the BIM vs charger and it appears your reversal is evidence based. ( you warm my engineering heart) We ordered the BIM and will give it a go. I wish I understood more about the functionality of the F-550 having dual alternators and batteries. I'm not sure if there is anything designated to support the house vs truck but hope to eventually figure it all out. In your intended lithium upgrade where are you with swapping out the converter? I for one don't see the value as we have solar roof top with a lithium charging profile, plus the BIM itself. Worst case I could start the genny and hook up my Noco lithium compatible charger.
Something I do intend to design in however is the ability to hook up portable solar. We used that in our travel trailer allot. Living in AZ, any chance to park in the shade and you take it. Roof top solar is compromised, but portable panels get the job done.

[DavidEM]

The standard three step charger switches to float too early so that Lithium batteries don’t get fully charged- about 80%. If you upgrade to a PD 9180 charger, you get a full charge and with 80 nominal amps, should charge faster.

In fact with 300 Ahrs of batteries I might go with a 100A charger or inverter/charger external to the converter for even faster charging.

Hey, I am a retired engineer too!

David

[Robert H.]

We also moved from a Lance to a Thor product. I was unhappy with the batteries supplied, so replaced them with two 100AH Renogy LiFePo batteries. I also installed a Renogy 2000 Watt inverter/charger, a 40 Amp MPPT solar controller, a LiBIM, and a Victron bluetooth battery monitor.

So far I am happy with this setup.

Another Engineer. Since much of my career was in Avionics, I was shocked at the methods and quality of work in our new Vegas. I have spent days cleaning up things, and suspect it will never be up to my standards, but I have to try.

On our last outing the heater quit. after some troubleshooting I found the DC wires pinched between the floor and the wall.

[chunker21]

Originally Posted by Lamokadave

Short version of a longer story.
New to us 2021 XG32
Had some visible corrosion in battery compartment, plus Thanks to these forums and particularly Judge, became aware that the BIM in the battery compartment might be incorrectly wired. (yes it was).
Experienced the adventure of removing the 4 -6 volts (required removing the top step completely) and discovered that the batteries were all dry.
2 are shot and 2 barely usable for the short term.
So we're now shopping replacements and decide to make life easier and eliminate to need to repeat this adventure considering ongoing maintenance.
Living in the SW we prefer to boondock when camping locally ie 150 mile radius
and in our prior Lance TT did that easily on 210A LA batteries and 300w solar.

Now the residential fridge and macerator toilet becomes a game changer.

When I was researching the Omni, the brochures said the XG32 had the macerator toilet but mine is gravity. Do you have the macerator or gravity? We both have 2021 Omni. Except for the minimal slope of the tank from the toilet to main part of the black tank, I prefer the gravity version.

[JamieGeek]

To get any detail at all you really need a good solar telescope and they can get pricey (like this one).

Oh wait not the solar you were referring too....sorry carry on.

[Judge]

As an FYI..... I installed (3) 170Ah Big Battery LiFePO4's for a total of 510Ah in my Magnitude SV34. I went with the Progressive Dynamics 60A Converter and LI-225 BIM. I also have two 160W Renogy Flexible Solar Panels. I also added the Victron Smart Shunt.

My system has performed very, very well.

[Chateau_Nomad]

Originally Posted by Robert H.

We also moved from a Lance to a Thor product. I was unhappy with the batteries supplied, so replaced them with two 100AH Renogy LiFePo batteries. I also installed a Renogy 2000 Watt inverter/charger, a 40 Amp MPPT solar controller, a LiBIM, and a Victron bluetooth battery monitor.

So far I am happy with this setup.

Another Engineer. Since much of my career was in Avionics, I was shocked at the methods and quality of work in our new Vegas. I have spent days cleaning up things, and suspect it will never be up to my standards, but I have to try.

On our last outing the heater quit. after some troubleshooting I found the DC wires pinched between the floor and the wall.

You may as well keep a small shop vac in your coach for awhile, considering the amount of sawdust, loose screws and stripped wire insulation you'll find. But look on the positive side... when you're done vacuuming out that construction debris your coach will be at least 25 pounds lighter!

[Lamokadave]

We also moved from a Lance to a Thor product. I have gained a new appreciation for how much better than most the Lance really is

[Lamokadave]

When I was researching the Omni, the brochures said the XG32 had the macerator toilet but mine is gravity. Do you have the macerator or gravity? We both have 2021 Omni. Except for the minimal slope of the tank from the toilet to main part of the black tank, I prefer the gravity version.
Definitely a macerator. Im surprised yours isn't unless it was one of those supply outages and Thor said THWI ship it

[Robert H.]

Originally Posted by Chateau_Nomad

You may as well keep a small shop vac in your coach for awhile, considering the amount of sawdust, loose screws and stripped wire insulation you'll find. But look on the positive side... when you're done vacuuming out that construction debris your coach will be at least 25 pounds lighter!

Plus, I have a supply of hardware for future projects. Every nook and cranny I look into gives new surprises.

[Lamokadave]

Originally Posted by Judge

As an FYI..... I installed (3) 170Ah Big Battery LiFePO4's for a total of 510Ah in my Magnitude SV34. I went with the Progressive Dynamics 60A Converter and LI-225 BIM. I also have two 160W Renogy Flexible Solar Panels. I also added the Victron Smart Shunt.

My system has performed very, very well.

I'm and true believer in KISS so we're trying to keep our solar replacement as simple as possible
I'm hoping the blue tooth functionality of the batteries we ordered replaces the need for the Victron kit. We also ordered the LI-225 BIM in lieu of a DC to DC charger for simplicity . I'm also not planning on a converter replacement because I really don't see it as necessary.
It only helps when I'm plugged in and not relying on the batteries.
The stock unit does no harm and maintains 80%+ battery capacity.
If boondocking driving to the site with alternator and solar gets me to 100%

Am I missing something here?

You also mentioned in one of your lithium conversion posts that you had no need to update the Firefly when others spent significant $$ to do so. Can you share some thoughts on that please.
I'm assuming it would be upgraded so that you maintain a battery triggered auto gen start before a severe battery depletion event. Is there any other lithium caused issue with the FF

[DavidEM]

Actually I think your keeping the standard converter and relying on the chassis alternator or solar to fully charge the batteries makes a lot of sense.

One thing that almost no one mentions about Li batteries is that they last longer when stored at 50-80% SOC. After a camping trip you could just disconnect the solar panels, let the OEM converter charge the batteries up to 80% and that will give you better battery life.

I think you said that you store with shore power plugged in but I may be wrong. If so, keep the solar plugged in. Maybe you could reset its controller to FLA batteries to not charge fully if you are storing throughout the winter.

David

David

[Robert H.]

[QUOTE=DavidEM;321578]Actually I think your keeping the standard converter and relying on the chassis alternator or solar to fully charge the batteries makes a lot of sense.

I agree and would not have replaced the converter if I did not purchase an inverter that not only did the changeover of AC but also had a built in charger.

I store with only solar, and can lave the battery on if desired. The draw from onboard systems with everything switched off is about one Amp. Solar quickly recovers to 100% when the sun comes out.

[happy]

Can the LI-225 BIM be installed early (before LI batteries) and used with flooded lead batteries?

I am planning to do incremental upgrades with LI Batteries coming toward the end.

[Robert H.]

Originally Posted by happy

Can the LI-225 BIM be installed early (before LI batteries) and used with flooded lead batteries?

I am planning to do incremental upgrades with LI Batteries coming toward the end.

It is only 4 wires so it took just a few minutes to change. Wait until you change the batteries. Many places were out of stock, so you might consider buying it when you find one.

[happy]

Thank you, I will do that....we do not yet have possession of RV but already have several items purchased......getting excited.