Here goes! My build thread to sleep a family of 9 (!!!) in a 2020 170" 4x4

[vanski]

Benefits on both sides IMO... we used our sprinter as a ‘generator’ this summer during blackouts here in nor cal. just ran some extension cords to the fridge and other essentials and made sure I was in full sun during the day. The AC in the box truck was also nice for the mrs... There’s no contest on cost going DIY lithium... but it takes building - knowledge base around these systems, significant time building, and patience... re patience, properly balancing LFP cells takes time and some patience.

being able to cart around batteries and an inverter could have its benefits for sure. And not having to understand the ins and outs of how the system works (at a build level). There’s something to be said about plug and play and having a warranty to back it up if something fails. For some folks, especially on the electrical side of things, it’s best for doctors to be doctors and lawyers to be lawyers, especially when so much is at stake with a large family in tote..

having said that, I have a new LFP bank that capacity tested at 590 amp hours. If I told you the cost, you’d cry because it’s so inexpensive compared to buying COTS (like 30% the cost of battleborn or the like). If I told you how many hours I have into it you’d also cry, laughing at me, because the time was/is absurd to design and build these systems in a custom application.

anyhow... I see both sides.. personally I like building these systems and knowing all the ins and outs of how everything works so I know the limits of the system and how to fix it if needed. I will also say, although not as good of a system as the Inergy, but still the same concept; I’ve had to help many goal zero people and at the end of the conversation regarding all the problems they are having, time to build custom.

 

[drodio]

@99sport yep that's a really good point re: everything we're trying to squeeze in! It's definitely a different style of build than most people need, when just accounting for 2-4 people. We're basically trying to create a tinyhome on wheels for a family of 9.

Speaking of which -- we're on a road trip right now with 7 of us and we were able to successfully sleep all 7 (3 adults + 4 kids) so that's a good start.

On 1 of the nights we used the Cabbunk, and on another night we used this inflatable bed that fits well between the rows of the seating.

Also — revised seating arrangement is working well, as is distance learning from the road!

 

[drodio]

@vanski I'd totally love to know what your 590 amp hour system costs as well as what a "regular" production installed system would cost. For reference, to get 600 ah w/ the Inergy would be:

• Flex 1500: $1,350 (or $1,500 once it ships; let's go w/ that number)
• 100ah Flex battery: $850 (once it ships, $950)

So that's $1500 + (6 batts x $950) = $7,200, which also includes the 1500 watt inverter & 13.8v regulated DC output.

The Flex has an integrated MPPT solar charge controller w/ a 14-90v solar input & 30A max charge rate; anything above that would require adding the MPPT solar supercharger module, which costs an additional $500 and adds two more 30A charge inputs, for a total of 90A. And if you wanted to get the full DC amp out capacity (two 30A Anderson PowerPole connectors, for 60 amps out, vs. 20A max out w/ the Flex 1500 via cigarette outlets), you'd also have to add the Flex DC to swap that out w/ the Flex 1500, which would cost $1,375. Since I only have two 175 watt panels, I don't need the MPPT supercharger because I'm not hitting that charge limit (although as solar panels continue to improve, I might want to add it later).

So let's call it $7,200 + $1,375 for the Flex DC just to get the full 60A out of the system & into the truck = $8,575.

LMK how the cost of your system vs. a standard built-in (Battleborn, etc) might cost, so we can get a good apples to apples comparison going.

 

[VanGoSki]

I posted this in another thread, just in case you haven't seen it.

 

[ZiggyStardust]

So let's call it $7,200 + $1,375 for the Flex DC just to get the full 60A out of the system & into the truck = $8,575.

you might need to get more than 60 amps out?

i guess with the inverter built in maybe not, but my inverter needs 200amps

 

[drodio]

@ZiggyStardust yeah agreed this is the biggest limiter in the current system -- how to actually get the power out of the Inergy and into the van. But I think 60 amps out will be enough -- and 20 amps out might be enough for much of the time. Here's how I've got things currently configured:

These are the appliances that have an energy draw:

1. Espar heater: Looks like it need 10-12 amps on startup, and then it draws about 2 amps per hour
2. Alpicool 55 liter fridge: Unsure what startup amp draw is (def. enough to make an AGM batt drop below the cutoff, throwing an error code!) but looks like a 0.5 amp/hour draw
3. MaxxFan: Anywhere between 0.2 and 4.4 amps, depending on fan speed; let's assume 4 amps.

That's all I've got that needs a constant draw, so let's call it 8 amps/hour ongoing, w/ more on startup on a per-device basis. And then I've got a 700 watt microwave that uses 110v that we'll run every now & then, which'll use 6ish amps (a bit more considering the inverter inefficiency). I'm hoping 20 amps will be enough to cover my needs but I'll report back! (LMK what I'm not considering here).

 

[vanski]

I’m not stating my exact material costs, but I’m building and selling 544ah/570ah banks for $1,950. Below pic of a Spec’d 272ah version (the $1,950 would be specd from the factory at 544ah, but is capacity testing to 570ah in my experience to date) that’s with 2x 120amp Overkill BMS (so I run 2p4s systems where each 4S is in parallel such that if a cell in one half of the bank were to fail you’d have a redundant battery such that you wouldn’t be hung out to dryAnd as much as I’d like to get to apples to apples that all depends on all the other chosen components which can vary greatly depending on need and appetite for cost. I will say the material cost for my current system is far below your outlined numbers, and that’s fully custom and not mediocre parts; I’m using a Xantrex 2kwatt/4kwatt inverter, Victron mppt charge controller (45amp), Victron bmv 712, blue sea combining solenoid, all blue sea hardware, etc, etc, etc.

i would say installation would be another $3k-$5k to have it done by someone who knows what they are doing.

of course anyone can do this work their self if they have the capability, time, and like to see some sparks!

here’s a 272ah/285ah batt I just got done building yesterday:

 

[RVBarry]

Hi, 150-180Ah of lithium and 200W of solar would let you run this indefinitely; people who want bigger systems that that usually want to run an air conditioner.

The microwave needs about 70A DC (7A AC). Not sure if the 60A limit you mentioned included the inverter.

1. Espar heater: Looks like it need 10-12 amps on startup, and then it draws about 2 amps per hour
2. Alpicool 55 liter fridge: Unsure what startup amp draw is (def. enough to make an AGM batt drop below the cutoff, throwing an error code!) but looks like a 0.5 amp/hour draw
3. MaxxFan: Anywhere between 0.2 and 4.4 amps, depending on fan speed; let's assume 4 amps.

That's all I've got that needs a constant draw, so let's call it 8 amps/hour ongoing, w/ more on startup on a per-device basis. And then I've got a 700 watt microwave that uses 110v that we'll run every now & then, which'll use 6ish amps (a bit more considering the inverter inefficiency). I'm hoping 20 amps will be enough to cover my needs but I'll report back! (LMK what I'm not considering here).

 

[OffroadHamster]

@ZiggyStardust yeah agreed this is the biggest limiter in the current system -- how to actually get the power out of the Inergy and into the van. But I think 60 amps out will be enough -- and 20 amps out might be enough for much of the time. Here's how I've got things currently configured:

These are the appliances that have an energy draw:

1. Espar heater: Looks like it need 10-12 amps on startup, and then it draws about 2 amps per hour
2. Alpicool 55 liter fridge: Unsure what startup amp draw is (def. enough to make an AGM batt drop below the cutoff, throwing an error code!) but looks like a 0.5 amp/hour draw
3. MaxxFan: Anywhere between 0.2 and 4.4 amps, depending on fan speed; let's assume 4 amps.

That's all I've got that needs a constant draw, so let's call it 8 amps/hour ongoing, w/ more on startup on a per-device basis. And then I've got a 700 watt microwave that uses 110v that we'll run every now & then, which'll use 6ish amps (a bit more considering the inverter inefficiency). I'm hoping 20 amps will be enough to cover my needs but I'll report back! (LMK what I'm not considering here).

6A @ 120V = 60A @ 12V. You need a minimum of 60A to run the microwave with everything else turned off. I have a 2000W inverter and all wiring is sized for 250A lease I try to pull a full 2000W @ 115V. My water heater draws 12A @ 120V which is a nice neat conversion to 120A DC 12V.

60A DC isnt much.

 

[RVBarry]

My water heater draws 12A @ 120V which is a nice neat conversion to 120A DC 12V.

Hi, don't forget to include inverter losses.

 

[drodio]

@vanski $2k for a 570ah system is awesome! So about 25% the cost of a modular Inergy system, although as you said, installation is extra and might make the total cost more like $5k to $7k. Still cheaper by as much as 40%; good to know the delta there. System looks great, too!

@RVBarry and @OffroadHamster re: microwave, yeah I should clarify: Since the inverter is built into the Inergy system, I don’t actually need to get that power out of the system and into the van to use the microwave — I just plug the microwave into one of the six available 110v outlets on the Flex. So it (and any other 110v appliances) won’t count towards the 20a max DC draw for the Flex 1500 or the 60a max DC draw for the Flex DC. That should mean that I need to transfer less power from the Inergy to the van vs. what someone might otherwise expect is needed. What‘ll be interesting is to see how many continuous watts the Flex 1500 can run at. The spec sheet says 1500 continuous / 3000 max but I don’t know if the inverter would overheat before it drained the battery. I’ll be curious to test that once it arrives.

FWIW for anyone who’s also just getting into this stuff, like I am: One trick I use to remember the conversion is the abbrev for West Virginia: WVa, i.e., Watts = Volts x Amp, and just solve for whichever value you need to solve for.

Speaking of the Inergy — used it today to do some work + for my daughter to do her remote learning schooling outside on the camping table that doubles as the bed platform! (Can’t wait for Starlink to really become a thing; that’ll be a total game changer... gig internet from even the most remote places on the planet.) The DragonFly tarp is also really great.

 

[vanski]

Beautiful shots! Wish my new build was usable! I’m spending too much time building out the electrical :-/..

to be clear, there’s still the inverter, charge controller, lots of other components which need to be added to my above finger in the wind estimate... it’d probably be a wash cost wise all said and done, but CUSTOM.

 

[drodio]

Beautiful shots! Wish my new build was usable! I’m spending too much time building out the electrical :-/..

I literally just spit out my drink ROFL when I read this!

But in all seriousness — good points on the cost of the other items, plus what is our time worth?!!

My fingers are crossed on the Flex’s regulated DC output, and runtime capacity of the 1500W inverter. Those two things would fix the biggest flaws of the Apex that I’m testing now.

 

[OffroadHamster]

Hi, don't forget to include inverter losses.

Order of magnitude anyway, my soon to be replaced lead bank is more than capable of delivering a "measly" 120A. It actually draws a hair over 1400w at the inverter, roughly 135A from the batteries.

Batteries are fun. Ive run a mig welder through an inverter off a couple car batteries. Ive also made a few crude trail repairs stick welding with said batteries (sans welding equipment, DCEN with jumper cables)

 

[drodio]

Just got back from an 8 day trip. Observations:

- the bed system worked great.
- used the Inergy Apex to power the fridge, Espar and MaxxFan w/o a problem. Also used it with a microwave. Below is a video of the testing I did. I did notice that the inverter was pulling 1300 watts on the batteries to power a 700 watt microwave.That’s almost double the microwave wattage, which surprised me. Anyone know why? Wasn’t expecting that. Having said that, I tested 10 mins continuous run on the microwave w/o a problem.

 

[SION1771]

The vendor doesn't have the DC cord in stock for the time being. Did your purchase include both an AC and DC cord, or just the DC cord instead of the AC?

Got the Wrappon Green dry flush toilet, which is a major splurge, but I’ve got people in my family that are more “glampers” than “campers” and it’s a game-changer for them. not having to keep a porta potty filled with water is another big benefit.
Unit works great. I recommend buying it from this vendor which had the best price I found and includes a DC cigarette lighter powered cord (most sellers have AC cord only).

 

[drodio]

@SION1771 both DC and AC!!!

 

[Kajtek1]

Just got back from an 8 day trip. Observations:

- the bed system worked great.
- used the Inergy Apex to power the fridge, Espar and MaxxFan w/o a problem. Also used it with a microwave. Below is a video of the testing I did. I did notice that the inverter was pulling 1300 watts on the batteries to power a 700 watt microwave.That’s almost double the microwave wattage, which surprised me. Anyone know why?

700W is rated microwave output, when input will be higher. Still drawing over 1000 W is surprising, even when you add inverter efficiency.
I would test the draw on household power to determinate inverter efficiency.

 

[SION1771]

You snooze, you lose... I was waiting until my credit card cycled to buy one and they now no longer offer the DC cable package. I called him up and chatted - he said the DC cables are redonkulously expensive, wired goofy, and he makes nothing on them. Though he did say the price is lower since they no longer include the 12v cable ($850 now - not sure what you paid).

There are pin-out photos online so I'll probably just make my own connector and cut the AC cable off and have it so I can reconnect the AC brick if need be.

@SION1771 both DC and AC!!!

 

[drodio]

@SION1771 you should point him to this thread and tell him that our recommendation to buy from him rests on the fact that he’s the only one offering the DC cable bundle! Very important for van life users like us.