Are there any glaring incompatibilities???

[Zerpersande]

I really hope not bc trying to find products that seem to have valid reviews AND are available to me here in Japan has been a hard row to hoe. I chose Ronogy not only because of good reviews and performance but also bc there is a Japanese distributor. And buying stuff in Japan right now while using my US-based credit card reduces the cost by about 25% bc of the artificially strong US$. Be that as it may, if anyone has any suggestions please speak now or lose the right to say ‘I told you so’ in the future.

Ronogy
Panels -200W x 3 19.2V/10.4W wired parallel for 57.6V/10.4W $690
Batteries - 100Ah x 2. Smart LIP $1,145
Inverter - LIP PSE 1000W $138
BT Module - $23

EPEver
Solar Controller 40A - $197

I also bought an Eenour portable AC unit. Power consumption about 210W. If I have to I’ll get a small tent, maybe even small enough to fit inside the NV200, and I know it will make the nights bearable. Amazon sale and US$ got me that for $275.

 

[Solarcoast]

I really hope not bc trying to find products that seem to have valid reviews AND are available to me here in Japan has been a hard row to hoe. I chose Ronogy not only because of good reviews and performance but also bc there is a Japanese distributor. And buying stuff in Japan right now while using my US-based credit card reduces the cost by about 25% bc of the artificially strong US$. Be that as it may, if anyone has any suggestions please speak now or lose the right to say ‘I told you so’ in the future.

Ronogy
Panels -200W x 3 19.2V/10.4W wired parallel for 57.6V/10.4W $690
Batteries - 100Ah x 2. Smart LIP $1,145
Inverter - LIP PSE 1000W $138
BT Module - $23

EPEver
Solar Controller 40A - $197

I also bought an Eenour portable AC unit. Power consumption about 210W. If I have to I’ll get a small tent, maybe even small enough to fit inside the NV200, and I know it will make the nights bearable. Amazon sale and US$ got me that for $275.

If your panels are wired in parallel they will only be 19.2v but 31.2 amps.

Wiring them in series will give you 57.6v and 10.4 amps

 

[Zerpersande]

If your panels are wired in parallel they will only be 19.2v but 31.2 amps.

Wiring them in series will give you 57.6v and 10.4 amps

Major brain fart there. Calculated for series, wrote parallel.

 

[frater secessus]

Ronogy
Panels -200W x 3 19.2V/10.4W wired parallel for 57.6V/10.4W $690

I think this was meant to say "wired in series for 57.6v/10.4A".

I don't see any glaring incompatibilities.

EPEver
Solar Controller 40A - $197

Didn't specify which one, but I think all their 40A have input limits of 100V or higher. Some of the smaller ones have 60v versions, which the proposed setup would exceed.

For charging LiFePO4 you will likely use the USER profile and make your own setpoints. Here is a quick guide to help with configuring setpoints for LiFePO4.

Note that some of the EpEver line can use the temp probe to stop charging at a given temperature. IIRC the new Triron line and all the new-style ≥50A controllers with detachable terminal covers. If yours isn't one of those you'd need a self-warming battery or a DIY battery warming setup to keep from charging below freezing. You didn't specify the exact battery model so I can't tell if it self-warms or not.

I also bought an Eenour portable AC unit. Power consumption about 210W.

If the A/C is running through the inverter we need to add ~10% inverter losses, so 241w. Either way, crude back-of-the-envelope math suggests if that's a constant/average draw it will consume 70-80% of the bank's capacity overnight. Best case scenario you'd need to replace 1,680Wh the next day (no other loads). Worst case is 1,928Wh the next day + depletion from any other loads + loads you are running the day of charging.

Average haul from 600w of solar in Tokyo (pdf):

• yearly average: 600w x 4 hours FSE x 0.83 average MPPT yield after losses = 1,992Wh
• December low: 600w x 2.23 hours FSE x 0.83 = 1,111Wh
• August high: 600w x 5.42 hours FSW x 0.83 = 2,699Wh

If you vehicle's alternator can handle it, even a small DC-DC charger would greatly assist the solar. 12v->24v DC-DC chargers do exist but they are not as common. I think Sterling and Victron are the most available, although I don't know about distribution in your area.

Please report back with what you find (effectiveness of the mini-A/C, actual power usage) for the benefit and curiosity of us onlookers.

 

[Zerpersande]

Didn't specify which one, but I think all their 40A have input limits of 100V or higher. Some of the smaller ones have 60v versions, which the proposed setup would exceed.

I can’t find anything on min panel input voltage. I do remember when researching this (obviously still ongoing) that there was a min voltage above battery voltage for a controller to work. I checked EPEver specs and found only max values. Here’s a pic of the spec sheet.

Tracer4215BNFor charging LiFePO4 you will likely use the USER profile and make your own setpoints. Here is a quick guide to help with configuring setpoints for LiFePO4.

Note that some of the EpEver line can use the temp probe to stop charging at a given temperature. You didn't specify the exact battery model so I can't tell if it self-warms or not.

The Renogy Smart battery is self-warming. As for setting the profile, excellent point. Well, I guess. Ithought that Smart aspect would cover that butbunless the battery and controller start dating I can see how the need to give the controller some info is required for optimal operation. And I may add that temp probe anyway. If the Smart function turns dumb the controller could catch it.

If the A/C is running through the inverter we need to add ~10% inverter losses.

This is an issue that needs some more thought. My calcs figured about 10 hrs max and I planned on no more than 6. And I was wondering if a thermostat would work to reduce it further.

If you vehicle's alternator can handle it, even a small DC-DC charger would greatly assist the solar. 12v->24v DC-DC chargers do exist but they are not as common. I think Sterling and Victron are the most available, although I don't know about distribution in your area.

I’ve already put one on the list. A Renogy DC-DC 12V 20A. Could I wire the batteries in series and make it a 24V system? Then add a 24v-12v charger for the fans, etc?

Please report back with what you find (effectiveness of the mini-A/C, actual power usage) for the benefit and curiosity of us onlookers.

Absolutely. This was a great help!

 

[Solarcoast]

.

I’ve already put one on the list. A Renogy DC-DC 12V 20A. Could I wire the batteries in series and make it a 24V system? Then add a 24v-12v charger for the fans, etc?

You could make a 24v system, but then you would also need a 24v inverter and 12v-24v DC DC charger (renogy only makes 12v-12v)

Although if you do go with a 24v system you will be able to utilize the full 600w of panels and be able to accept more panels in the future. A 40a charge controller into a 12v bank won't be able to utilize the full 600w of panels, as 40a@ 14.6v (charge voltage) is only 584w. Not a big loss as the array will rarely if ever produce the full 600w but worth mentioning.

 

[Zerpersande]

You could make a 24v system, but then you would also need a 24v inverter and 12v-24v DC DC charger (renogy only makes 12v-12v)

Although if you do go with a 24v system you will be able to utilize the full 600w of panels and be able to accept more panels in the future. A 40a charge controller into a 12v bank won't be able to utilize the full 600w of panels, as 40a@ 14.6v (charge voltage) is only 584w. Not a big loss as the array will rarely if ever produce the full 600w but worth mentioning.

Well, let’s look at this setup…
Renogy Smart LiFePO4 100Ah x 2 in series for 24V
Renogy 200W 19.2V/10.4W x 3 = 57.6V / 10.4W
(If really needed) x 4 = 76.8V / 10.4W
Controller EPEver Tracer4215BN 40A
Inverter Giandel 1200W
Charger Victron Energy Blue Smart IP67 24V-12A
Converter Empire DC 24V to DC 13.8V. 45A

I‘m a bit lost on finding a DC-DC charger to use the vehicle‘s alternator. I’d rather buy another panel to ensure that I have enough charge capacity in the summer months. Any other time I won’t see a shortage of electrical power.

Would a DC-DC converter with 12V or 24V inputs double as either battery charger in 24V-12V mode and a alternator-battery charger in 12V-24V mode. Like in the pic?

​

 

[Solarcoast]

Now I'm confused, are you going for a 24v battery configuration or 12v? I know you said two batteries in the op but wasn't clear if that was parallel or series. Assumed parallel since you mentioned the 12v renogy dc-dc charger, but if you are going 24v you'll need a different one.

The best options imho are sterlings or victron orions. Both can be had in a variety of input/output voltages and amp ratings.

https://www.sterling-power-usa.com/batterytobatterychargers.aspx
https://www.victronenergy.com/dc-dc-converters/orion-tr-smart
For the orions there are both chargers and dc-dc converters. You'll want the charger models, although supposedly some of the converter models have adjustable output and could also be used as a charger. No experience with those however.

 

[frater secessus]

I checked EPEver specs and found only max values. Here’s a pic of the spec sheet.

Max {the primary concern in this context} is 150V (138V in real-world conditions) and minimum is battery voltage + 2v.

The Renogy Smart battery is self-warming.

Excellent.

My calcs figured about 10 hrs max and I planned on no more than 6. And I was wondering if a thermostat would work to reduce it further.

I used 8 hours for my rough math. A thermostat could work, though it might need a delay before restarting. My understanding is compressors don't like being cycled on/off rapidly.

I use a thermostat now on my lithium warming mat, and have used one before with good results while experimenting on a peltier cooler I got at a thrift store for $10.

As for setting the profile, excellent point. Well, I guess. Ithought that Smart aspect would cover that

IMO BMS protections are like guardrails on the sides of the highway. If you hit them you've already left the lane, crossed the shoulder... They don't keep the battery in the normal/healthy range, they prevent severe damage when things get out of hand.

Of course, if the demand is heavy and necessary we run them hard, {bounce off the guardrails}, and worry about it later. Manufacturer claims of "up to 54 quintillion cYcLes!!!!!!!!" are typically predicated on gentle use: charge/discharge at 0.2C, discharging to 20% State of Charge, cell temps 25deg C. But the batts should {make it} through the warranty period even if treated roughtly.

’ve already put one on the list. A Renogy DC-DC 12V 20A.

That will work fine. Hopefully the alternator is rated ≥60A.

Could I wire the batteries in series and make it a 24V system? Then add a 24v-12v charger for the fans, etc?

Yes, assuming the battery specs allow it (they usually do). it would require a 12v > 24v DC-DC charger and 24vdc -> {insert local grid power voltage here} inverter. The charge controller and series-connected panels will handle 24v banks fine.

This approach might be practical if:

1. the A/C is expected to be your primary load (tail that wags the dog); and
2. the alternator is rated ≥120A. A DC-DC charger that outputs 20A @ 24v is pulling ~40A from a 12v alternator.

Otherwise 24v on smaller setups may be a PITA due to the dominance of 12v gear in this marketspace.

{edited for missing words}

 

[Zerpersande]

Now I'm confused, are you going for a 24v battery configuration or 12v? Assumed parallel since you mentioned the 12v renogy dc-dc charger, but if you are going 24v you'll need a different one.

When you read my first comments I WAS describing a 12V system. But your comment about the lack of full utilization of the solar panels got me interested in 24V systems. And there are some other advantages such as being able to use smaller wires/lugs. And in my case I could power my AC directly from the battery and not have to buy a 12VDC > 24VDC converter.

The best options imho are sterlings or victron orions.

Checking into the Sterling link proved useful. First, the price of about $450 (that's their list so maybe a bit cheaper?) put them out of the game. Second, they do have a distributor in Japan. Said distributor does conversions apparently so maybe they can point me to where I can buy some 4-way stretch carpeting.

The Victron series I found a 12V >24V charger. About $270. So that's in 'Save for later' in Amazon.

For the orions there are both chargers and dc-dc converters. You'll want the charger models, although supposedly some of the converter models have adjustable output and could also be used as a charger. No experience with those however.

I'm interested in learning more about the converter models. More importantly, I think that the 'charging from the alternator' issue is perhaps of more importance to many others than for myself. I currently have no plans to live solely out of my van. I'm going to spend a lot of time in it, but my plan is to buy some land in the mountains and have a 'forest' of my own. For the $450 I would spend on the Sterling I could buy a small generator, hook it up as a shore power source through a transfer switch, and assist my solar system that way. AND it would give me a reliable power source for equipment at my 'basecamp'.

 

[Zerpersande]

Max {the primary concern in this context} is 150V (138V in real-world conditions) and minimum is battery voltage + 2v.

So the EPEver, as a 12V/24V controller, will still do the trick.

A thermostat could work, though it might need a delay before restarting. My understanding is compressors don't like being cycled on/off rapidly.

Having tested the portable unit I now think that the thermostat option won't work. The unit is turned on by depressing a film-type button and holding it down for a second or two. Kill the power and then turn it back on won't restart the machine. It does have a 'Night Mode'. Which means no AC but the fan blows hot air over your naked and sweating body.

IMO BMS protections are like guardrails on the sides of the highway. If you hit them you've already left the lane, crossed the shoulder... They don't keep the battery in the normal/healthy range, they prevent severe damage when things get out of hand.

My 'type' is that if I can optimize something then said optimization will be done.

That will work fine. Hopefully the alternator is rated ≥60A.

The NV200 has an alternator rated at 150A, so good to go there.

Yes, assuming the battery specs allow it (they usually do).

I'll give the Renege Smart battery a Google and make sure.

It would require a 12v > 24v DC-DC charger

Yeah, and I've found a Victron Orion that will work.But (and I'm copy/pasting this from the above post)...

I think that the 'charging from the alternator' issue is perhaps of more importance to many others than for myself. I currently have no plans to live solely out of my van. I'm going to spend a lot of time in it, but my plan is to buy some land in the mountains and have a 'forest' of my own. For the $450 I would spend on the Sterling I could buy a small generator, hook it up as a shore power source through a transfer switch, and assist my solar system that way. AND it would give me a reliable power source for equipment at my 'basecamp'.

and 24vdc -> {insert local grid power voltage here} inverter.

The inverters they sell here apparently work okay even though the grid is 100V. That difference generally only becomes important in heating devices. I had to buy a 100VAC > 110VAC step-up transformer that I swapped off my under-the-counter coffee maker from the US and onto my crock pot anytime I made chili.

The charge controller and series-connected panels will handle 24v banks fine.
This approach might be practical if:

1. the A/C is expected to be your primary load (tail that wags the dog); and
2. the alternator is rated ≥120A. A DC-DC charger that outputs 20A @ 24v is pulling ~40A from a 12v alternator.

Yeah, the expansion is for the AC. I've pondered it but even though the additional outlay is significant, it builds more potential into the overall system.

Otherwise 24v on smaller setups may be a PITA due to the dominance of 12v gear in this marketspace.

The PF (PITA Factor) already exists. I'm only able to afford all of this (psychologically) because of the exchange rate. I can't even find 4-way stretch carpeting.