24v solar system for van

Hi

• 24V Pure Sine Wave Power Inverter 3000Watt DC 24V to AC120V with Dual AC Outlets with Remote Control 2.4A USB and LED Display Giandel
• 2x Valence U27-12XP LiFePO4 | 12V 138AH 1.766 kWh or 2x Battle Born LiFePO4 Deep Cycle Battery - 100Ah 12v-connected series to form a 24v battery. Note in future I will be add two more
• 2x Newpowa 200W Monocrystalline 200 Watt 12V Solar Panel High Efficiency Mono. May look at other brands. Note: will add two more in the future
• EPEVER MPPT Solar Charge Controller 40A 150V PV Solar Panel Controller Negative Ground W/ MT50 Remote Meter + Temperature Sensor PC Monitoring Cable. (I’m wondering if this will be large enough for future or should I move up to 60 amp??)
• Uxcell New BIG-Size Voltage Converter Regulator DC/DC DC 24V to DC 12V 40A 480W Buck Transformer Waterproof
• bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt
• 12V Input to 24V Output 70 Amps DC to DC Converter
• Pro Batt Ultra Battery to Battery Chargers, Non Waterproof, (Drip Resistant IP21) Green Label - 12V-24V 70A BB122470

I have not included wires, fuses, breaker, etc.



I want to be able to use shore power and shore power to change my batteries. I want to use my alternator to charge my batteries. Any place that I may be able to save a few dollars? Am I missing anything?

Thanks so much for your assistance!

I would recommend that you checkout some of Will's blueprints - they cover everything you need.

Other considerations:

1. You need a DC-DC charger, not a DC-DC converter, in order to charge your batteries from your van's electrical system. I would also urge you to be conservative on the current - more is not better, especially at idle when your alternator has minimum cooling and is also trying to charge your starter battery.
2. Do you absolutely need 3,000W? Again, bigger is not better because the higher the rated output, the greater are the losses. If you can do with lower than 3,000W, then you can easily run from a 12V battery system and save money on the 12V-24V conversion kit.
3. Consider including a battery monitor e.g. Victron BMV or AiLi
4. I would recommend including a panel mounted shore power connector and connecting this to an ATS on the inside to switch between shore and backup power.
5. I would recommend buying an inverter with a built-in charger rather than buying a separate unit. Cheaper? More convenient?
6. 400W os solar would generate around 1,600Wh of energy on a good day in Summer. If you consume more than this, your battery bank will slowly deplete. Consider doing an energy audit.

Good luck with your project.

Hi

1. Thanks so much for your input but don't I need Uxcell New BIG-Size Voltage Converter Regulator DC/DC DC 24V to DC 12V 40A 480W Buck Transformer Waterproof to go from 24v to 12v for my 12v appliances, lights, refrigerators, etc.?
2. My thoughts were that in the future when I move to my container home that I'd need the 3000 watts
3. battery monitor, yes I forgot that thanks!
4. MOES Dual Power Controller 50A 5500 Watt Automatic Transfer Switch for Off Grid Solar Wind System ATS DC 12V 24V 48V AC 110V 220V
5. I will look into that good idea
6. I got a Kill-a-watt meter and in process of audit!

Again, thank you!

1. Yes, you do need that device to power your 12V loads, that's not the device I was referring to. I am assuming that the component you label as "12V Input to 24V Output 70 Amps DC to DC Converter" is the device you are planning to use to charge your battery from your alternator source. This is the device that needs to be a charger, not just a converter. You cannot charge a lithium-ion battery with a 24V source. Lithium-ion batteries, as with lead-acid batteries, need a staged CC/CV charging profile, with an absorption voltage of around 3.65V per cell, or 29.2V for an 8S battery (i.e. 24V nominal battery). Something like this would do. Other manufacturers are available e.g. Samlex, CTEK etc.
2. OK
3. OK
4. Yes, and no. A typical ATS is a very simple device: do I have primary power? OK, do nothing. Primary power lost? OK, switch over to Backup. The MOES has a more advanced use case and actually operates in reverse: do I have backup power? OK, do nothing. Is my load more than my backup can supply? OK, switch to primary. Is the battery supplying my backup source too low? OK, switch to primary. It is designed for systems where you want the inverter to be supplying your system's AC loads but if the load is too big, or the battery gets to low, switch over to shore power. Most systems require the simple solution, if I have shore power, use that, if I disconnect shore power, switch over to the inverter. Simple ATS switches are much, much cheaper e.g. $50. But if you want to focus on self-generation e.g. solar power, even with shore power available, the MOES can be useful.*
5. OK
6. OK

And you are welcome!

*If you are thinking about including a battery charger and focusing on self-consumption, you might want to consider buying something like the Victron MultiPlus or similar devices from e.g. Samlex. They operate as an inverter, charger and can automatically switch between multiple sources as required. The MultiPlus also has PowerAssist that may be of benefit, and can be linked to other devices in their ecosystem for remote control, data analytics etc.

1. I see what you are saying. If I move to Victron MultiPlus 24/3000/70-50 120V VE.Bus Inverter Charger, I no longer need 24V Pure Sine Wave Power Inverter 3000Watt, 60amp MPPT Charge Controller 48V/36V/24V/12V, VICTRON ENERGY ORION-TR SMART 12/24-15A (360W) ISOLATED DC-DC CHARGER, and Xantrex 8080915 PROwatt SW Auto Transfer Switch with Xantrex Technology Inc, 808-9001 Remote Panel for Prowatt Sw. This would cost be a little less than $200 but I would be moving up to a Victron unit that works in unison. Also I will be increasing inverter from 60 amps to 70 amps. I think that extra $200 is well worth it.

2. Will P had suggested "Skip the B2B battery charger and use a current regulated boost converter to charge from alternator. It will save a lot of money." Now if I go that route, I'll save about $400. That's a significant savings. I seen this one-not sure if it will work: MPPT Boost Solar Panel Battery Regulator Charger Controller 24V-72V Bluex 1

Wait-I make a mistake! Victron MultiPlus 24/3000/70-50 120V VE.Bus Inverter Charger; it does not have Charge Controller! So now the Victron MultiPlus cost about $460 more! Victron are very nice but I'm on a budget!

I think that I'm going to try to find out more about a current regulated boost converter to charge from alternator. I just need to know what to look for.

Greg57 said:

Victron MultiPlus 24/3000/70-50 120V VE.Bus Inverter Charger; it does not have Charge Controller! So now the Victron MultiPlus cost about $460 more! Victron are very nice but I'm on a budget!

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Apologies if I cause any confusion! Victron do make an all-in-one, called EasySolar, but they are far from cheap. And I believe it only outputs 230V.

The Victron ecosystem has a 'mode' called ESS (if memory serves), which is basically 'self-consumption' mode. It centrally monitors and configures all components on a 'solar first' basis i.e. eek out as much as possible from solar then, if exhausted, connect to the grid. With the Victron ecosystem this is just a configuration, whereas buying the components above, you're 'hard wiring' that behaviour, which might be fine. But Victron is a tier-1 prodcut manufacturer, you get a lot of bells and whistles, but, of course, these cost money. For example, the MultiPlus has the ability to sell solar to the grid, if this is not something you need, then you're buying spec needlessly.

Victron produced a whitepaper on 'self consumption' called Energy Unlimited, it's a good read.

Greg57 said:

I think that I'm going to try to find out more about a current regulated boost converter to charge from alternator.

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Could you link me to this? It's just that per my original comment, you cannot charge a battery with a simple 'boost converter'.

It is on this forum, search- Do the math $$ before going 24V in a Van.

I will check out Victron Ecosystem

I realize there is nice features on Victron but I'm trying to save money so any ideas to reduce cost would be appreciated. Do you have any suggestion for my proposed system below? I listed it a 800 watts system but as you can see it is 400 watts. My plan was to add more panels and batteries in the future. As you can see I will be able to charge my 24v battery bank using Victron Energy Orion-TR Smart. I will also be able to charge via shore power. Besides wires, lugs, fuses, breaker did I forget anything? I need to do a long term energy audit to make use that I haven't over or under designed system. I also need to put together a wiring diagram. Appreciate all your input as well as anyone elses

24v system 800 watts

• 24V Pure Sine Wave Power Inverter 3000Watt DC 24V to AC120V with Dual AC Outlets with Remote Control 2.4A USB and LED Display Giandel $480
• 4x Valence U27-12XP LiFePO4 | 12V 138AH 1.766 kWh or 2x Battle Born LiFePO4 Deep Cycle Battery - 100Ah 12v-connected series to form a 24v battery. $2100
• 2x Newpowa 200W Monocrystalline 200 Watt 12V Solar Panel High Efficiency Mono. May look at other brands. $760
• EPEVER MPPT Solar Charge Controller 40A 150V PV Solar Panel Controller Negative Ground W/ MT50 Remote Meter + Temperature Sensor PC Monitoring Cable. $180
• Uxcell New BIG-Size Voltage Converter Regulator DC/DC DC 24V to DC 12V 40A 480W Buck Transformer Waterproof $39
• bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt $20
• VICTRON ENERGY ORION-TR SMART 12/24-15A (360W) ISOLATED DC-DC CHARGER $265
• Xantrex 8080915 PROwatt SW Auto Transfer Switch $58 with Xantrex Technology Inc, 808-9001 Remote Panel for Prowatt Sw $25

Not sure if these are available with 110v input, but... https://www.redarc.com.au/the-manager30-with-redvision-display
Triple input - Solar, Alternator, Shore power (240v)

Only 30A output to batteries, but that's still a decent amount of power and enough for a 200AH system
Redarc stuff is absolutely top notch.

Greg57 said:

I'm trying to save money so any ideas to reduce cost would be appreciated.

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Anything 'Victron' in there is going to cost more money and will likely have a cheaper alternative.

yes, I agree but for the DC DC Charger 12-24v, it is the only solution that I can think of. Actually there are other solution but they are more expensive than Victron. Do you know of a lower cost solution? I do have concerns about my van's alternator damage

Greg57 said:

Do you know of a lower cost solution?

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I don't off hand but it would surprise me if nobody else in the whole world has thought of creating a 12-24V DC-DC charger.

tictag said:

I don't off hand but it would surprise me if nobody else in the whole world has thought of creating a 12-24V DC-DC charger.

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Basic question. Why are you doing a 24V battery bank if you have 12V loads? Do you also have 24V loads? 400W of solar isn't too much for a 12V bank, just needs a 40A charge controller. You might want a slightly smaller inverter, but if not, 12V 3000W is available.

my ultimate plan is to move this system from my van to my container home after living in van for 2-3 years traveling the country. I would add more panels and batteries.

Greg57 said:

my ultimate plan is to move this system from my van to my container home after living in van for 2-3 years traveling the country. I would add more panels and batteries.

Click to expand...

Would it be cheaper to just buy a new 24V inverter then than pay for all of the converters now? Buy an even number of batteries that can be rewired when needed.

I compared a 12v and 24v system with cost. There is basically no difference in cost-see below. Cost of 12v MPPT!

24v system 800 watts

• 24V Pure Sine Wave Power Inverter 3000Watt DC 24V to AC120V with Dual AC Outlets with Remote Control 2.4A USB and LED Display Giandel $480
• 4x Valence U27-12XP LiFePO4 | 12V 138AH 1.766 kWh or 2x Battle Born LiFePO4 Deep Cycle Battery - 100Ah 12v-connected series to form a 24v battery. $2100
• 4x Newpowa 200W Monocrystalline 200 Watt 12V Solar Panel High Efficiency Mono. May look at other brands. $760
• EPEVER MPPT Solar Charge Controller 40A 150V PV Solar Panel Controller Negative Ground W/ MT50 Remote Meter + Temperature Sensor PC Monitoring Cable. $180
• Uxcell New BIG-Size Voltage Converter Regulator DC/DC DC 24V to DC 12V 40A 480W Buck Transformer Waterproof $39
• bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt $20
• VICTRON ENERGY ORION-TR SMART 12/24-15A (360W) ISOLATED DC-DC CHARGER $265
• Xantrex 8080915 PROwatt SW Auto Transfer Switch $58 with Xantrex Technology Inc, 808-9001 Remote Panel for Prowatt Sw $25
• 
  
• I have not included wires, fuses, breaker, etc.
• 
  
• Total $3,930.00

12v system 800 watts

• GoWISE Power PS1004 3000W Continuous 6000W Surge Peak Power Pure Sine Wave Inverter with Starter Cables and 4 Output Sockets $390
• 4x Valence U27-12XP LiFePO4 | 12V 138AH 1.766 kWh or 2x Battle Born LiFePO4 Deep Cycle Battery - 100Ah 12v-connected series to form a 24v battery. $2100
• 4x Newpowa 200W Monocrystalline 200 Watt 12V Solar Panel High Efficiency Mono. May look at other brands. $760
• EPEVER MPPT Charge Controller 80 amp - 12V/24V/36V/48V Auto, Negative Ground MAX 200V 6000W Input Fit Lithium AGM Gel Flooded User Blacklight LCD Display Large-Amp(Tracer 8420AN) $390
• bayite DC 6.5-100V 0-100A LCD Display Digital Current Voltage Power Energy Meter Multimeter Ammeter Voltmeter with 100A Current Shunt $20
• Renogy 40A 40A DC to DC Battery Charger 40A for Flooded, Gel, AGM, and Lithium Using Multi-Stage Charging or 200 Amp Battery Isolator and Relay $43
• Xantrex 8080915 PROwatt SW Auto Transfer Switch $58 with Xantrex Technology Inc, 808-9001 Remote Panel for Prowatt Sw $25
• I have not included wires, fuses, breaker, etc.
• Total $3,825.00 that’s $105 less to go towards extra cost for wires which will cost you more for 12v but this is for a van-not long runs
• • Total $3,825.00 that’s $105 less to go towards extra cost for wires which will cost you more for 12v but this is for a van-not long runs

One difference in cost between 12V and 24V is the solar charge converter. Basically what drives the cost of these up is the amp ratings. A solar charge converter like a Victron Smart Solar 100/20 can deliver 290W of solar power to a 12V battery (14.5V @ 20A). The exact same charger can deliver 580W to a 24V battery (29V @ 20A).

To equal this with a 12V battery requires a 40A or bigger SCC and these are not cheap. Plus the wiring must be much larger which also costs more and it a pain to deal with.

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yes! that's my point. For 12v I need EPEVER MPPT Charge Controller 80 amp -$390 for 24v I need EPEVER MPPT Solar Charge Controller 40A $180. Plus lower cost of wire and lugs. If I would let go of my desire for alternator charge the savings would even be larger.