Feedback on my Camper Schematic and Energy Calcs?

[Dhowman]

OK, here it is. Been working on this for a couple months now and gotten feedback on individual pieces but not the whole setup.

>>> High Res Version (click pic when link opens) <<<​

Have already received the 4 300W panels and ElectroDacus SBMS0 w USB/WiFi and DSSRs and ordered the Li cells (March ETA) w enough bus bars for all terminal connections shown.

About to purchase everything else but would appreciate any red flags or adjustments that might be needed before I do.

Heavier weight red/black wires will be #3 AWG and the rest #10. Heavier weight grey wires are grounded AC cords w 3-prong plug connections at the inverter.

All AC appliances and 24V DC consumers are shown and are switched via Sonoff (RF, EWeLink/IOT, or by pressing manual buttons on the unit) using the Normally Open terminals.

Electrodacus SBMS0 includes:

• 8S cell balancing on charge and discharge
• HV and Low Temp (XT1) Cutoff via EXTIO4
• LV Cutoff (AC & DC) via EXTIO3
• CHARGE current monitoring = current at PV Shunt (1-direction)
• LOAD current monitoring = CHARGE current plus current at ADC1 Shunt (bi-directional)
• 12 months of historical and RT reporting/charts on SBMS (& on a PC via WiFi)
• Downloadable data files via USB

12V DC consumers will include:

V A W​

12 2 24 Engel Fridge​

12 2 24 Fantastic Fan (to be replaced by Maxair in near future)​

19 2 38 27" Computer Monitor​

20 5 90 Laptop #1​

20 3 64 Laptop #2​

15 6 90 Laptop #3​

12 1 12 Apple TV​

12 1 15 Echo Spot​

12 1 12 Mofi LTE Router​

12 1 6 WiFi Router​

12 0 1 Natures Head Composting Toilet​

12 3 30 Water Pump​

5 1 5 Phone​

5 0 0 Toothbrush​

5 1 3 Waterpick​

n.a. 28 414 TOTAL​

Everything in this list that came w an AC adapter has been converted to run straight from DC. Will use buck converters to adjust supplied voltage where needed.

I calculate that worst consumption days (when I might have to work) will require about 4kWh, which will bring me down to about 50% SOC from full or, more likely, 40% if I don't charge 'em all the way up to 100%.

Because it'll take me about 7 hrs of sun to replace that, I've designed space to add another 600W (50% more) of solar which will get that number down to about 4.5 hours.

Rest of the time, I'll probably only be consuming about 1-2kWh per day.

All these calcs assume I'll only capture about 50% of the rated capacity of the panels on average. Would an MPPT improve this? Probably not enough to make a difference. I sized my panels to get near MPPT performance.

Why 3 laptops? I'm an IT Consultant. ;-)

But I'm not an electrician or an EE so any advice/feedback greatly appreciated!

 

[Dhowman]

Updated post above w link to a higher res image. Looks like the forum downsizes large images. This one's pretty sharp. Just click the picture the link takes you to to open up the high res version.

Thanks!

 

[Off grid Colorado]

Is the extra dssr for more panels?

 

[Dhowman]

Is the extra dssr for more panels?

It is, per this in my OP ...

"Because it'll take me about 7 hrs of sun to replace that, I've designed space to add another 600W (50% more) of solar which will get that number down to about 4.5 hours."

 

[Dzl]

I think I've found my solar design soulmate :D

I'm also (in the early stages) of designing a vehicle mounted system, also looking at using the SBMS0, also planning 24/12v hybrid system (but plan to use 24v battery bank, also considering 150AH higees in an 8s config (though I might go with CALB for physical durability), and also obsessively interested in eschewing AC adapters and converting everything I can to run more efficiently off DC directly (my latest curiosity is leveraging USB-PD as much as possible.

I'm surprised I wasn't aware of your build/design before now (until the SBMS thread--thanks again for the super helpful explanation)!

In terms of your build, I'm curious what sort of vehicle you are building.

I believe your Engel is capable of running directly from 24v, is there a reason you are opting for 12v?

If your laptops are newer and charge via USB-C / USB-PD there are 24v to USB-PD adapters available that avoid the conversion down to 12 and than back up to 19-20v, with the added bonus that the same outlet will charge any PD capable device automatically at 5v, 9v, 12v, or 20v (and I believe non-PD devices at 5v)

 

[Dzl]

Also I forgot to ask about your cell configuration and BMS.

Your diagram states 8S2P (two groups of 8 series connected cells, in parallel--which would normally need two BMS'), but it looks like 2P8S (pairs of cells configured in an 8S configuration), and I only see 1 BMS, am I right in assuming 2P8S 8 pairs of cells series connected)?

 

[Dhowman]

In terms of your build, I'm curious what sort of vehicle you are building.

I believe your Engel is capable of running directly from 24v, is there a reason you are opting for 12v?

Sonoff is limited to 10A so ran 24V only to the items I wanted to control w that. If I ran 'em at 12, would have exceeded the 10A rating. Didn't want a separate 24V system to manage (e.g. separate breaker board, etc.)

 

[Dhowman]

Also I forgot to ask about your cell configuration and BMS.

Your diagram states 8S2P (two groups of 8 series connected cells, in parallel--which would normally need two BMS'), but it looks like 2P8S (pairs of cells configured in an 8S configuration), and I only see 1 BMS, am I right in assuming 2P8S 8 pairs of cells series connected)?

Yeah, it should read "2P8S."

 

[Dzl]

View attachment 7215


Sonoff is limited to 10A so ran 24V only to the items I wanted to control w that. If I ran 'em at 12, would have exceeded the 10A rating. Didn't want a separate 24V system to manage (e.g. separate breaker board, etc.)

Love FWCs! I almost bought a ranger model a while back (same as the eagle but made for an 8 foot bed--not many of them out there).

 

[Spleeft]

The spec for the 600w Nutribullet rounds this build out nicely! ( sorry I cant contribute more, nice job ! )

 

[Solarfun4jim]

OK, here it is. Been working on this for a couple months now and gotten feedback on individual pieces but not the whole setup.

View attachment 6408

>>> High Res Version (click pic when link opens) <<<​

Have already received the 4 300W panels and ElectroDacus SBMS0 w USB/WiFi and DSSRs and ordered the Li cells (March ETA) w enough bus bars for all terminal connections shown.

About to purchase everything else but would appreciate any red flags or adjustments that might be needed before I do.

Heavier weight red/black wires will be #3 AWG and the rest #10. Heavier weight grey wires are grounded AC cords w 3-prong plug connections at the inverter.

All AC appliances and 24V DC consumers are shown and are switched via Sonoff (RF, EWeLink/IOT, or by pressing manual buttons on the unit) using the Normally Open terminals.

Electrodacus SBMS0 includes:

• 8S cell balancing on charge and discharge
• HV and Low Temp (XT1) Cutoff via EXTIO4
• LV Cutoff (AC & DC) via EXTIO3
• CHARGE current monitoring = current at PV Shunt (1-direction)
• LOAD current monitoring = CHARGE current plus current at ADC1 Shunt (bi-directional)
• 12 months of historical and RT reporting/charts on SBMS (& on a PC via WiFi)
• Downloadable data files via USB

12V DC consumers will include:

V A W​

12 2 24 Engel Fridge​

12 2 24 Fantastic Fan (to be replaced by Maxair in near future)​

19 2 38 27" Computer Monitor​

20 5 90 Laptop #1​

20 3 64 Laptop #2​

15 6 90 Laptop #3​

12 1 12 Apple TV​

12 1 15 Echo Spot​

12 1 12 Mofi LTE Router​

12 1 6 WiFi Router​

12 0 1 Natures Head Composting Toilet​

12 3 30 Water Pump​

5 1 5 Phone​

5 0 0 Toothbrush​

5 1 3 Waterpick​

n.a. 28 414 TOTAL​

Everything in this list that came w an AC adapter has been converted to run straight from DC. Will use buck converters to adjust supplied voltage where needed.

I calculate that worst consumption days (when I might have to work) will require about 4kWh, which will bring me down to about 50% SOC from full or, more likely, 40% if I don't charge 'em all the way up to 100%.

Because it'll take me about 7 hrs of sun to replace that, I've designed space to add another 600W (50% more) of solar which will get that number down to about 4.5 hours.

Rest of the time, I'll probably only be consuming about 1-2kWh per day.

All these calcs assume I'll only capture about 50% of the rated capacity of the panels on average. Would an MPPT improve this? Probably not enough to make a difference. I sized my panels to get near MPPT performance.

Why 3 laptops? I'm an IT Consultant. ;-)

But I'm not an electrician or an EE so any advice/feedback greatly appreciated!

Love your layout. Would have been extremely helpful if all 'chassis grounding' was shown also. Great job with the detail.

 

[Dhowman]

Love your layout. Would have been extremely helpful if all 'chassis grounding' was shown also. Great job with the detail.

Thanks, no chassis grounding but that may change.

 

[dsilver]

Love the diagram. What did you use to create it?

 

[Dhowman]

Love the diagram. What did you use to create it?

Visio. Took me a while to figure out how to get it to do what I wanted, but eventually was able to connect everything so I could drag stuff around and re-position lines and objects to be just where I wanted 'em. Actually worked out better than I thought it would. Easy to add/change/delete stuff, which I'm constantly doing.

 

[cass3825]

On a negative-grounded vehicle, I would fuse the lfp bank on the positive side vs. the negative.

 

[Goosepower]

OK, here it is. Been working on this for a couple months now and gotten feedback on individual pieces but not the whole setup.

View attachment 6408

>>> High Res Version (click pic when link opens) <<<​

Have already received the 4 300W panels and ElectroDacus SBMS0 w USB/WiFi and DSSRs and ordered the Li cells (March ETA) w enough bus bars for all terminal connections shown.

About to purchase everything else but would appreciate any red flags or adjustments that might be needed before I do.

Heavier weight red/black wires will be #3 AWG and the rest #10. Heavier weight grey wires are grounded AC cords w 3-prong plug connections at the inverter.

All AC appliances and 24V DC consumers are shown and are switched via Sonoff (RF, EWeLink/IOT, or by pressing manual buttons on the unit) using the Normally Open terminals.

Electrodacus SBMS0 includes:

• 8S cell balancing on charge and discharge
• HV and Low Temp (XT1) Cutoff via EXTIO4
• LV Cutoff (AC & DC) via EXTIO3
• CHARGE current monitoring = current at PV Shunt (1-direction)
• LOAD current monitoring = CHARGE current plus current at ADC1 Shunt (bi-directional)
• 12 months of historical and RT reporting/charts on SBMS (& on a PC via WiFi)
• Downloadable data files via USB

12V DC consumers will include:

V A W​

12 2 24 Engel Fridge​

12 2 24 Fantastic Fan (to be replaced by Maxair in near future)​

19 2 38 27" Computer Monitor​

20 5 90 Laptop #1​

20 3 64 Laptop #2​

15 6 90 Laptop #3​

12 1 12 Apple TV​

12 1 15 Echo Spot​

12 1 12 Mofi LTE Router​

12 1 6 WiFi Router​

12 0 1 Natures Head Composting Toilet​

12 3 30 Water Pump​

5 1 5 Phone​

5 0 0 Toothbrush​

5 1 3 Waterpick​

n.a. 28 414 TOTAL​

Everything in this list that came w an AC adapter has been converted to run straight from DC. Will use buck converters to adjust supplied voltage where needed.

I calculate that worst consumption days (when I might have to work) will require about 4kWh, which will bring me down to about 50% SOC from full or, more likely, 40% if I don't charge 'em all the way up to 100%.

Because it'll take me about 7 hrs of sun to replace that, I've designed space to add another 600W (50% more) of solar which will get that number down to about 4.5 hours.

Rest of the time, I'll probably only be consuming about 1-2kWh per day.

All these calcs assume I'll only capture about 50% of the rated capacity of the panels on average. Would an MPPT improve this? Probably not enough to make a difference. I sized my panels to get near MPPT performance.

Why 3 laptops? I'm an IT Consultant. ;-)

But I'm not an electrician or an EE so any advice/feedback greatly appreciated!

Do you need the Sonoff to handle the on/off for the inverter or is that just a choice? Could you find power from another source? It does seem better to run the diesel heater from a 24v source though. Just wondering if the Sonoff could be eliminated. Not for your system, just in general.

 

[Dhowman]

Do you need the Sonoff to handle the on/off for the inverter or is that just a choice? Could you find power from another source? It does seem better to run the diesel heater from a 24v source though. Just wondering if the Sonoff could be eliminated. Not for your system, just in general.

Nope. No need for the Sonoff to control the Inverter. It's just a "nice to have" for me so I can control or observe the on/off status when I'm not physically inside the camper (or in bed, in the case of the heater ). For example, i can switch the exterior lights from the cab of the truck w/o having to run any wiring between the camper and the truck that it sits on.

 

[Goosepower]

I think I've spent more time looking at your setup than all the collective time I've spent in the Louvre. Having schematics like this are great learning tools. Does anyone know of a place where more schematics are being shared?

 

[Dhowman]

I think I've spent more time looking at your setup than all the collective time I've spent in the Louvre. Having schematics like this are great learning tools. Does anyone know of a place where more schematics are being shared?

Thanks @Goosepower . I found that most of the diagrams I was looking at to try and figure out how mine needed to be set up were "conceptual" i.e. single lines drawn between components that didn't really contain any other of the necessary details (e.g. polarities, series vs parallel connections, wire sizes, etc) that I needed to understand before I put everything together and not have it blow up *grin*. Took a while but got to the point, ID'g all those details in the course of reading how individual components worked and adding them to my diagram the way the needed to be added, that I really felt I started to better understand how all those pieces, individually and collectively, were designed to work. Glad to hear that you found it helpful. Cheers!

 

[John Frum]

Why are the fuses on the negative busbar on the doubled battery leads?
Are they within 18 inches of the battery?
Why are the battery leads doubled?