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Hey lovely people! New here, new to van life, and just starting my build with absolutely no experience at all! I want to start living in my van full-time by October and travel around the US & Mexico. I work Mon-Fri 9am-5pm and plan on always being nearby some sort of co-working space for this reason. (so I may spend more time in cities, excepts weekends)

I have no idea what I'm doing and have SO much to learn. I've been watching lots of youtube, reading a ton of blogs. However, I still feel like I know absolutely nothing when it comes to electrical. I also know that planning the electrical setup is one of the 1st steps in the build phase so I'm feeling very stuck.

I'm trying to get an understanding of what I'll be using that needs power and how much power I anticipate drawing on a daily basis. To ultimately help me understand what size batteries I need, inverter, how much solar panels I need, etc.

Here is a google sheet I created to try and calculate my needs. I'm struggling to find out how much consumption the products I plan on having use. I haven't bought these products yet, so I'm trying to find information online but it's really not helping. Manufacturers' website doesn't seem to be helping me much either.
Can someone take a look at the google sheet, especially the purple text, and let me know if you have any insight or help you can provide me?

Ultimately, the point of the google sheet is to understand:
• what size battery do I need, and how many
• what size inverter do I need
• ideal amount of solar Watts I need
• size of the charge controller
 

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That google file is a PITA. Can you give us a more friendly format?
Oh no! I'm so sorry! What's PITA about it? So I understand what I need to fix.
(Is it the fact that it's a Google file? Or the layout of my columns/rows?)
 

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I found the sheet fine. Your use is just a bit more than mine. I use a bit more than half my power overnight when the solar is off so count on using about 40 A-H from when the batteries are full until you start pumping power back in (I use 27-33). That load would mean a 200+ A-H battery set, mine is 2- 215 A-H 6 volt flooded lead acid golf cart batteries form Sam’s club. I have 200 Watts of solar and it has proven enough but plan your solar to add another 100 if your usage rises. That system would let you go a full 1.5 days w/o charging at all and you would want to drive or plug in if it were going to be another day w/o sun. I can go 2 days but seldom have zero sun days as some power is made if there is any. Only a fully rain event keeps it at none.
 

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I would recommend finding a solar company in your area that can help you figure it out and set you up with everything you need, possibly even install it for you or at least be willing to pick up the phone if you have questions.
 

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The hot water tank is 12A @ 120V. If you are planning to run it off the battery/inverter, it will draw 120A @ 12V plus some inverter inefficiency. At .5 hour per day that would be more than 60 AHr.
 

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That’s for sure it so large I can’t even read it on my 12" iPad Pro😝 I can imagine what it would look like on a phone. For computer desktop viewing only I’m afraid.
 

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Oh no! I'm so sorry! What's PITA about it? So I understand what I need to fix.
(Is it the fact that it's a Google file? Or the layout of my columns/rows?)
@smashley

I’m using an iPhone & can read your google doc fine (others may find it harder - a photo is usually better - but I find it easy to read)

The big thing I can tell you is 12v & 120v and battery energy needs to be the big consideration. Anything that you want to create “heat” with your battery (like “hot” water), is a big big factor. To understand this I will identify the the hot water heater & inverter 120v from battery power.

If it takes 20mins to heat 2.5gals @ 1500W & 90% efficiency inverter @ 12.5 volts would be approximately 120 to 140 Amp Hours

20mins = 45 amp hours

The Amp Hour rating for batteries is usually rated at a 20 hour discharge & if you deplete the energy quickly the Ahr rating is hugely reduced

The long & short of it is; If you want to run high demand 120v items like heaters for even a short period of time you need a massive battery system & ability to charge it

So IMO the crossroad of your design at this point is your need of 120v from your batteries What are your intentions with 120v & batteries as your google sheet indicates you want your batteries to power your hot water tank😳

Caveat; I could have read your google sheet wrong - Did I get your intent right?

edit; also depending upon the battery, the state of charge SOC & Ahr rating; a conservative design would allow you to deplete your batteries to 50% SOC, so if you have a 100Ahr system you really only have 50 Ahr “Useable”. evenless if not discharged over the typical 20hr timeframe. Research battery chemistry and specifications if you’re planning to use your inverter 120v more than just a minor amount (heating your van or hot water by electricity via battery power is a huge endeavour)
 

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Discussion Starter #9
@smashley

I’m using an iPhone & can read your google doc fine (others may find it harder - a photo is usually better - but I find it easy to read)

The big thing I can tell you is 12v & 120v and battery energy needs to be the big consideration. Anything that you want to create “heat” with your battery (like “hot” water), is a big big factor. To understand this I will identify the the hot water heater & inverter 120v from battery power.

If it takes 20mins to heat 2.5gals @ 1500W & 90% efficiency inverter @ 12.5 volts would be approximately 120 to 140 Amp Hours

20mins = 45 amp hours

The Amp Hour rating for batteries is usually rated at a 20 hour discharge & if you deplete the energy quickly the Ahr rating is hugely reduced

The long & short of it is; If you want to run high demand 120v items like heaters for even a short period of time you need a massive battery system & ability to charge it

So IMO the crossroad of your design at this point is your need of 120v from your batteries What are your intentions with 120v & batteries as your google sheet indicates you want your batteries to power your hot water tank😳

Caveat; I could have read your google sheet wrong - Did I get your intent right?

edit; also depending upon the battery, the state of charge SOC & Ahr rating; a conservative design would allow you to deplete your batteries to 50% SOC, so if you have a 100Ahr system you really only have 50 Ahr “Useable”. even less if not discharged over the typical 20hr timeframe. Research battery chemistry and specifications if you’re planning to use your inverter 120v more than just a minor amount (heating your van or hot water by electricity via battery power is a huge endeavour)
I want the hot water to clean dishes with and wash my face before bed. According to the product specs it takes 15min to heat up the 2.5G tank. I took a guess that I would prob use it max 30m in one day.

The intent of this sheet is to document all the consumption I will be using to figure out what size battery & how many batteries I need.
My guess is I'll need 3 100 aH lithium batteries and a 2000W inverter. But I'm not sure.
 

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I want the hot water to clean dishes with and wash my face before bed. According to the product specs it takes 15min to heat up the 2.5G tank. I took a guess that I would prob use it max 30m in one day.

The intent of this sheet is to document all the consumption I will be using to figure out what size battery & how many batteries I need.
My guess is I'll need 3 100 aH lithium batteries and a 2000W inverter. But I'm not sure.
I have a 1500W 120v electric hot water tank. It takes 20mins to heat the tank to scolding temps. My solution if “boon-docking” & shore power is not available is to plug my Honda 2200 into my shore power & only turn on my hot water tank “breaker switch” on my AC panel

My original idea was to have fully electric for everything, until I got educated about inverters & batteries & costs. Anything heat is huge energy & if you are trying to perform that with 12v batteries it is huge (doable, but not at my budget or interest once I understood how big a deal it is). I choose what I believe to be simpler
 

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I have a 1500W 120v electric hot water tank. It takes 20mins to heat the tank to scolding temps. My solution if “boon-docking” & shore power is not available is to plug my Honda 2200 into my shore power & only turn on my hot water tank “breaker switch” on my AC panel

My original idea was to have fully electric for everything, until I got educated about inverters & batteries & costs. Anything heat is huge energy & if you are trying to perform that with 12v batteries it is huge (doable, but not at my budget or interest once I understood how big a deal it is). I choose what I believe to be simpler
So would you suggest a gas heater? Sorry I'm not sure I'm understanding what your suggestion is.
 

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Hey lovely people! New here, new to van life, and just starting my build with absolutely no experience at all! I want to start living in my van full-time by October and travel around the US & Mexico. I work Mon-Fri 9am-5pm and plan on always being nearby some sort of co-working space for this reason. (so I may spend more time in cities, excepts weekends)

I have no idea what I'm doing and have SO much to learn. I've been watching lots of youtube, reading a ton of blogs. However, I still feel like I know absolutely nothing when it comes to electrical. I also know that planning the electrical setup is one of the 1st steps in the build phase so I'm feeling very stuck.

I'm trying to get an understanding of what I'll be using that needs power and how much power I anticipate drawing on a daily basis. To ultimately help me understand what size batteries I need, inverter, how much solar panels I need, etc.

Here is a google sheet I created to try and calculate my needs. I'm struggling to find out how much consumption the products I plan on having use. I haven't bought these products yet, so I'm trying to find information online but it's really not helping. Manufacturers' website doesn't seem to be helping me much either.
Can someone take a look at the google sheet, especially the purple text, and let me know if you have any insight or help you can provide me?

Ultimately, the point of the google sheet is to understand:
• what size battery do I need, and how many
• what size inverter do I need
• ideal amount of solar Watts I need
• size of the charge controller
Have you tried downloading the power audit spreadsheet found here? How Many Batteries are needed in a DIY Camper Van Electrical System
It's what I used. Nate does a good job explaining how much juice the individual items use and how to enter them into the spreadsheet.
 

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I have an 800W 120V water heating element (Sous Vide) which can be placed in a suitable container up to about 4 gallons. Even at 800W it still draws about 75-80 DC amps with the inverter. Due to the high amp draw, I only use this with the engine running, usually while driving. But can be used when idling as well.

If you heat it in an insulated cooler, it will stay hot for several hours after closing the cooler lid.
 

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My thoughts:

Hot water... Marine style water heater off engine coolant lines

Interior heating... Diesel parking air heater with small tank under hood

No propane needed, and minimal electricity use. Heating anything sucks the A-Hrs.
 

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Hi,

I think the fridge estimate is spot on.

The MaxAir fan seems high to me -- if you use it a couple hours at 50% (which moves a lot of air) and (say) leave it on low at night for 8 hours, thats (0.6amp)(2hr) + (0.1 amp)(8 hrs) = 2 amp-hrs -- maybe allow for as much as 5 amp-hrs for a really warm day/night.

I don't get the dometic stove? Are you saying that this is an electric stove that uses 7200 watts (yikes!).
Most people use butane or propane stoves, which have near zero electricity use.
If it really uses 7200 watts and you used it at that wattage for an hour, you are talking about (7200 watt-hrs)/(12 volts) = 600 amp-hrs. There must be something wrong with your 7200 watt number (which you have in the table at 700 KiloWatts).

Laptop battery capacity is normally about 60 watt-hrs, which with 90% efficient charging would be about (60 wh)/(12 volts*0.9) = 6 amp-hrs from fully flat to fully charged.

Heating 2.5 gallons of water from 50F to 120F takes (2.5 gal)(8.33 lb/gal)(1 BTU/lb)(120F - 50F) =1500 BTU, which would be about 440 watt-hrs, or (with 90% efficiency) be 41 amp-hrs out of your 12 volt battery.

The lights, pump and gas detector are pretty small potatoes.

If you add a propane (or other fossil fuel) furnace, that will add about 20 amp-hrs to run the fan if you run it all night.

If you do the water heating and cooking with propane (or some other fossil fuel), your loads would be much like mine (or RD's) and a couple of $90 golf cart batteries would be ample (rather than $3000 worth of Li batteries) -- but it depends on your budget and what you really want out of the van.
Personally, I think there is a lot to be said for a simple system that costs a few hundred dollars, is simple enough to understand and maintain and fix easily, and where you don't have to worry about screwing up and ruining your $3000 of Li batteries -- but, people make different choices based on their needs.

Gary
 

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Discussion Starter #16
I have an 800W 120V water heating element (Sous Vide) which can be placed in a suitable container up to about 4 gallons. Even at 800W it still draws about 75-80 DC amps with the inverter. Due to the high amp draw, I only use this with the engine running, usually while driving. But can be used when idling as well.

If you heat it in an insulated cooler, it will stay hot for several hours after closing the cooler lid.
Something like this?
 

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Hi,

I think the fridge estimate is spot on.

The MaxAir fan seems high to me -- if you use it a couple hours at 50% (which moves a lot of air) and (say) leave it on low at night for 8 hours, thats (0.6amp)(2hr) + (0.1 amp)(8 hrs) = 2 amp-hrs -- maybe allow for as much as 5 amp-hrs for a really warm day/night.

I don't get the dometic stove? Are you saying that this is an electric stove that uses 7200 watts (yikes!).
Most people use butane or propane stoves, which have near zero electricity use.
If it really uses 7200 watts and you used it at that wattage for an hour, you are talking about (7200 watt-hrs)/(12 volts) = 600 amp-hrs. There must be something wrong with your 7200 watt number (which you have in the table at 700 KiloWatts).

Laptop battery capacity is normally about 60 watt-hrs, which with 90% efficient charging would be about (60 wh)/(12 volts*0.9) = 6 amp-hrs from fully flat to fully charged.

Heating 2.5 gallons of water from 50F to 120F takes (2.5 gal)(8.33 lb/gal)(1 BTU/lb)(120F - 50F) =1500 BTU, which would be about 440 watt-hrs, or (with 90% efficiency) be 41 amp-hrs out of your 12 volt battery.

The lights, pump and gas detector are pretty small potatoes.

If you add a propane (or other fossil fuel) furnace, that will add about 20 amp-hrs to run the fan if you run it all night.

If you do the water heating and cooking with propane (or some other fossil fuel), your loads would be much like mine (or RD's) and a couple of $90 golf cart batteries would be ample (rather than $3000 worth of Li batteries) -- but it depends on your budget and what you really want out of the van.
Personally, I think there is a lot to be said for a simple system that costs a few hundred dollars, is simple enough to understand and maintain and fix easily, and where you don't have to worry about screwing up and ruining your $3000 of Li batteries -- but, people make different choices based on their needs.

Gary
Thank you for looking at the spreadsheet 💜💜

I doubled the Amp on the Maxx air fan in my chart because I'll have 2 of them. Maybe that's why it seems high to you. If I have two would you still think 5 amp-hrs a day would be correct?

The domestic stove specs were provided in Kw not W. I think it's for the lighter. But I guess I could just use a match to light it myself. To be honest, I'm not sure what the 7200Kw is for, I just found it on their website and added it to my chart. 🤷‍♀️

I plan on chasing warm weather + summer, so I won't need a heating unit for the air, just a heating tank for my water. I've briefly considered getting a propane water heater, but propane scares me frankly so I was trying to avoid it if I could. However, if the amount of energy needed for an electric hot water tank is just not worth it, then I will def consider propane. It'll just mean tackling another scary & unknown part of my build that I was trying to avoid tbh.

I'm not sure if you noticed, but I have a lot of ? in my chart. and that's because I couldn't find any of those specs online. Is it normal to not be able to find specs like these? I don't understand why I'm having such a hard time finding this data to fill out my chart.
 

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There’s more to sizing the system than just adding up loads. We’ve never had our 200Ah batteries down to 50%, probably below 60% less than a dozen times in 5 years. Yet when these batteries die, I will upgrade to 300Ah and I look forward to the day. Why? Draw-down voltage.

We use our 700W MW (1100W draw) every day. There is also the high-draw Instapot. When the batteries get down to 75% or so, the inverter can get unhappy when these heavy draws pull the voltage down. (800W water boiler and Sous Vide are not as much a problem.)

Seriously consider the Sous Vide for heating water. Do the heating when you have solar, alternator or shore power. Use the water when you want. No mixing, no wasted water, no plumbing. If 105° shower feels good, heat to 105°, or a bit more if it’s going to be a while.

See my build blog for details.
 

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My thoughts:

Hot water... Marine style water heater off engine coolant lines

Interior heating... Diesel parking air heater with small tank under hood

No propane needed, and minimal electricity use. Heating anything sucks the A-Hrs.
There's absolutely no way I have the skills & knowledge to mess with the engine of the van. :(
I'm already struggling enough with just this solar panel + battery + inverter setup.
 
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