installing a 48v 200a system with a Balmer alt

[rmanbike]

Hi Kinda new here,
I am purchasing a new 2024 Thor Axis 25.7 with the Ford 7.3 that has the optional 2 12v alternators, 250amp for chassis battery and 160amp for the house batteries. I will be converting to a 48v LiFePO system, with 2 48v 100a LiFePO batteries. Balmer makes 48v alternators that replaces/direct fit of the 160a alternator. Without getting into all the details, will I be the first on these iRV2 forums installing a 48v LiFePO system with a 48v alternator in a motorhome? And solar panels too!

[twinboat]

Don't think so, it's been done by a few.

[rmanbike]

Originally Posted by twinboat

Don't think so, it's been done by a few.

By Airstream the Atlas E1

[d23haynes57]

Besides bragging rights, I just have to wonder why? With modern inverter technology the gains are minimal, and you will end up still needing to maintain a 12-volt house battery-electrical system for some of the systems that will be in place such as controls for the AC, furnace(s), water pump, etc. RV, Bus, Truck systems are still using 24-12-volt systems. Consider that for keeping things serviceable by others. A bit interesting is that you are looking at an entry level rig and immediately looking at costly upgrades instead of reasonable priced tweaks. Many RVs including Diesel pushers don't have the single 250-amp alternator. I only have 270 in my 08 Nimbus 42 footer. With that I am supporting 900 A/H lithium. With the 2nd 160 amp keeping it 12 volts gives you a lot of flexibility to combine and use both. Also, what comes with the rig will be covered by the standard warranty and extended warranties if you get one. The Balmer set up you will be on your own and parts are not always readily available. It is specialty stuff. Good stuff but specialty.

[rmanbike]

Originally Posted by d23haynes57

Besides bragging rights, I just have to wonder why? With modern inverter technology the gains are minimal, and you will end up still needing to maintain a 12-volt house battery-electrical system for some of the systems that will be in place such as controls for the AC, furnace(s), water pump, etc. RV, Bus, Truck systems are still using 24-12-volt systems. Consider that for keeping things serviceable by others. A bit interesting is that you are looking at an entry level rig and immediately looking at costly upgrades instead of reasonable priced tweaks. Many RVs including Diesel pushers don't have the single 250-amp alternator. I only have 270 in my 08 Nimbus 42 footer. With that I am supporting 900 A/H lithium. With the 2nd 160 amp keeping it 12 volts gives you a lot of flexibility to combine and use both. Also, what comes with the rig will be covered by the standard warranty and extended warranties if you get one. The Balmer set up you will be on your own and parts are not always readily available. It is specialty stuff. Good stuff but specialty.

I understand it's an entry-level motorhome but for most people it is the floorplan that matters the most, and of course getting a 50% discount off MSRP doesn't hurt. I do recall many people saying that why would you want to go to 12 V when 6 V is just fine and it works, your horns your lights and starter is 6 V, you won't be able to find any way to find repair parts that are 12 V. Remember the good old days
Tesla is going to 48 V, that is the future. It really should be so so obvious why it is a future, that's why it's commonly seen in a boating industry now, parts and repairs are easily found if you look other than the old school RV world.

[Argosy]

If you scroll to the bottom of this page to a box called "Similar Threads" the first mention of 48 volt was 2016.

I'm also wondering why you want to go this direction? The basic reason for higher voltage is the reduction in current which allows smaller cables and components. Powering it from the motive engine suggests you don't intend to boondock for extended periods, I doubt if the motorhome is all electric. It's relatively small which means both cargo capacity and space are at a premium. It's brand new which means it will have issues to deal with, if any are electrical or can be tied to your work you will have to repair them. Most important in my mind is the materials and the construction methods used aren't conducive to major disassembly and upgrades.

Use some of the money you plan to spend on this to travel for the warranty period. If you find you really need more capacity that year will give you a lot better idea of how much and how to integrate it into the motor home.

[d23haynes57]

Yes, they offer some great, efficient floor plans. Depending on your actual ability to use and travel you will likely find that there are other areas that you will look to upgrade. For most RVers this line of coach is usually the first or of four or five before they decide and settle on what they really need. Even I am on # 4 now and shopping. Your road conditions where you travel will play a large part of your satisfaction or not. You have a great drive line for that rig size. First trip in the Northeast and suspension upgrades are coming. Take some hills and the engine-fan noise will be there. Winter and hot summer use will raise the construction of the body issues.
I am trying to be informative and speak from experience of myself, friends, customers.
Maximize and enjoy what you have. Some solar make sense. Hopefully you do have a good battery, inverter, charger combination and a generator. That generator will probably run for about $2 to 3$ per hour. The worst thing you can do for it is not use it. How many hours of generator time will you look to avoid covering the cost of a 38-volt system. Also, high output alternators are not long-life components and usually they do have anywhere near full output at idle and low speeds.

[SafariBen]

Why all the 48V hate? I almost converted my 95 Cummins to 24V, volts that is, not valves, real engines don't need more than 12 valves. I was replacing the starter, alternator, and the fuel solenoid wouldn't have been very hard, but the transmission would have been expensive, or required 12v anyway.


Probably good thing I didn't. But 12V is ridiculous for over 2,000w of inverter, or 1,000w solar. If I get around to Li, I'll definitely go with 48V, maybe not drop the coin for a Balmer, maybe put a 120V AC on the engine, or maybe get a used Cummins 48V alternator that they're supposedly using soon.



Dennis is the one who made the disparaging comment about multiple cheap parallel (12v) Li batteries, well, 48v is THE best answer to that. The all in one converter/charger/solar controller price is all you need to prove that.



I spend my money how I feel, and like seeing how other people go about their projects. A solar friend often complains about how people ask him the payback, but don't care about the payback of their own toys.


I can imagine even with the Balmer, this upgrade with you doing the work could cost a fraction of what a small "solar package" would cost on a Tiffin or Newmar.

[Donskiman]

Look through this thread. Pretty amazing stuff by Mike Mas.

https://www.irv2.com/forums/f103/can...as-564692.html

[SafariBen]

That system is "12/51/120 volt Dual Voltage / Dual Inverter Hybrid 32,000 watt hour", and frankly that is terrible design.



The other one in this thread is 24V, best I can tell 6 parallel batteries, not the way I'd do it, BUT, they went with a 24-12 converter to power the chassis battery WHICH powers all the 12v loads, eliminating the house 12v battery bank. https://www.irv2.com/forums/f59/rv-s...ss-661749.html

Originally Posted by d23haynes57

With modern inverter technology the gains are minimal, and you will end up still needing to maintain a 12-volt house battery-electrical system for some of the systems that will be in place such as controls for the AC, furnace(s), water pump, etc. RV, Bus, Truck systems are still using 24-12-volt systems...

If you're going to go 24V, I don't see much reason not to go 48V, the solar and inverter sizing and efficiency is the main benefit. You rarely need 20-30KWH for the 12V system, and if you did, then you'd probably be to the point that upgrading the whole 12V wiring would be needed, and that's not happening on a typical RV.

[shepardmike]

I wonder if Thor would perform any warranty work....

[rmanbike]

Originally Posted by Argosy

If you scroll to the bottom of this page to a box called "Similar Threads" the first mention of 48 volt was 2016.

I'm also wondering why you want to go this direction? The basic reason for higher voltage is the reduction in current which allows smaller cables and components. Powering it from the motive engine suggests you don't intend to boondock for extended periods, I doubt if the motorhome is all electric. It's relatively small which means both cargo capacity and space are at a premium. It's brand new which means it will have issues to deal with, if any are electrical or can be tied to your work you will have to repair them. Most important in my mind is the materials and the construction methods used aren't conducive to major disassembly and upgrades.

Use some of the money you plan to spend on this to travel for the warranty period. If you find you really need more capacity that year will give you a lot better idea of how much and how to integrate it into the motor home.

First of all, two hours of driving we fully charge the lithium batteries, so yes I will be Boondocking at least five out of ever seven days. You assume so many things you know nothing about. I don't need your opinion, so let's just keep it technically if you're able to do that.

[rmanbike]

Originally Posted by shepardmike

I wonder if Thor would perform any warranty work....

I would say 95% of all Thor owners have that same sentiment!

[d23haynes57]

Originally Posted by SafariBen

Why all the 48V hate? I almost converted my 95 Cummins to 24V, volts that is, not valves, real engines don't need more than 12 valves. I was replacing the starter, alternator, and the fuel solenoid wouldn't have been very hard, but the transmission would have been expensive, or required 12v anyway.


Probably good thing I didn't. But 12V is ridiculous for over 2,000w of inverter, or 1,000w solar. If I get around to Li, I'll definitely go with 48V, maybe not drop the coin for a Balmer, maybe put a 120V AC on the engine, or maybe get a used Cummins 48V alternator that they're supposedly using soon.



Dennis is the one who made the disparaging comment about multiple cheap parallel (12v) Li batteries, well, 48v is THE best answer to that. The all in one converter/charger/solar controller price is all you need to prove that.



I spend my money how I feel, and like seeing how other people go about their projects. A solar friend often complains about how people ask him the payback, but don't care about the payback of their own toys.


I can imagine even with the Balmer, this upgrade with you doing the work could cost a fraction of what a small "solar package" would cost on a Tiffin or Newmar.

I don't see this as 48-volt hate. 48-volt systems have their place. If designing things from new and using nonvehicle charging sources there are some advantages. My comments were trying to inform that the benefits may not be all that great and yes, some comments were trying to relate costs versus value. However, many vehicles and busses use 24-volt electrical system and in the Diesel world 24-volt alternators are off the shelf stuff.
As for 3,000-watt inverters using 12 volts, that is now a common standard. Made easier with AGM and no problem at all for a properly sized and wired lithium battery bank. 600 A/H capacity with 400-amp BMS dose it with ease. 3/0 or 4/0 cable for a long run and you are good. An inverter/charger will need a 10-gauge 30-amp branch circuit for either 2,000 or 3,000 watts. The 3,000 will need to reduce charger load as the pass though load increases. Most have programable setting for that. 3,000-watt inverter with up 150-amp charge with a 600 amp/400-amp BMS. is good add more capacity to increase run time.
As for batteries, I have over 40 years' experience with batteries in many applications including motive power, (forklifts), large scale UPS systems, and also manage a 600 KW solar installation, 12 years now. I manage batteries that are large enough that if a cell fails, it gets replaced. I have also supported UPS systems up 100 kw and 850 KW gensets.

My comment about the multiple cheap battery sets was not meant to be disparaging and I apologize for coming across that way. For 400 amps of capacity, A single battery is best. However, since most are still limited to 200-amp load for the BMS, you need a second battery to do that. The system will work better with two, 200-amp batteries with 200-amp BMS each tan with 4–100-amp batteries. The only worse than multiple batteries in parallel is multiple in series. If going to a 24- or 48-volt system, my recommendation is to use 24- or 48-volt batteries. Reducing the number of batteries also reduces the cabling.

Again, my participation on this forum is one offering information and when needed assistance. Maybe at some point get a following. For customer recommendations and even decisions for my primary occupation I use the standard of "what would I choose if it was my money"? If only our government would think the same way. Seriously, I have no intention to offend anyone but if folks make decisions based on my comments or recommendations, I want to be able to support that information, especially since I don't know it all!