Off Grid RV system with 96v battery

[Flyingjibus]

I am about halfway through Will's book and have been cramming solar stuff into my brain for the last 2 weeks. I am a quick study and have some engineering experience. Designing a system that is not standard at all (from what I can tell) so I wanted to put some of this stuff out there before I buy too much more stuff and find out it isnt right.

System is for an adventure van. (think van life but much more recreational in nature)
Primary loads are as follows:
CPAP machine
Roof Fan
Lights (lots of lights, I have energy to spare, and I like LEDs)
water pump for sink
Charging small electronics via USB
Charging hobby style lipo batterys (using a 12v hobby charger)
And probably a 12v fridge type thing once i figure out my actual capacity. I think i have the power for it.

So, it all starts with the battery. I have this battery already and it is the catalyst for this whole system, and is not going to be swapped out.

The battery: (already have it)
a single lithium module from Farasis,made for the single pack Zero FX (electric dirt style bike)
we can call it a 96 volt battery for this discussion (94v-110v range)
25 amp hours/2400 watt hours
Will charge at 25 amps if you want to.

The charge controller (already have it):
Sunnysky 96v 60a MPPT

Amazon.com

min panel voltage is listed as 120v, max Watts of panels listed as 6800w

The panels (have not purchased yet):
Sunpower Black 250w

• Rated Power: 250W
• Open circuit voltage (VOC): 48.8V
• Max power voltage (VMP): 40.5 V
• Short circuit current (ISC): 6.56A
• Max power current: 6.17 A
• Maximum system voltage: 600V UL
• Power Tolerance: -3%/+5%
• Number of Cell: 72
• Fuse Rating: 20 A
• IP65 3 diode Junction Box with MC4 compatible connectors
• Frame: Anodized black aluminum alloy
• Weight: 33 lbs
• Dimensions: 61.4″ x 31.4″ x 1.8″

Van is a promaster 159. I dont have a ton of room on the roof, but 4 of these panels in series will fit well, and based on my understanding of everything should work well to charge this system.


12 volt step down( I have this) :
Thunderstruck Motors 96V Isolated DC-DC converter for EV's

TSM48DC-DC

Thunderstruck Motors 96V Isolated DC-DC converter has 13 8V output with a max of 50 amps burst at 12V Allowable Input is 72-135v 8 x5 5 Footprint 3 lbs Input Yellow 96V B+ Grey 96V B- Green 96V B+ On Output Red 12V + Black 12V- Do not connect black to grey Specs The ipDCIS series isolated...

www.thunderstruck-ev.com

This should power everything I intend to run at 12v with plenty of amperage room to spare. I am currently trying to figure out if I should connect this to the 96v output of the charge controller so the system can see the load. I dont see why I should not do this, but if I am missing something please let me know.

AC power:
One of the unique things about this battery is it's ability to fool 120v AC devices into thinking they are on grid power. the engineer who worked on this battery (my cousin) has assured me almost any AC device I want to use in the van will most likely work just plugged into this battery, so right now the plan is to just wire a small breaker box directly off the battery and have a couple house outlets in the "Kitchen" area of the van. Kitchen type appliances (think rice cooker or crock pot) are the only thing I would likely ever use that are set up for 120 volt AC. I have been using battery packs to charge laptops for years, and will just continue that trend. TV's and such are for houses, not vans out in the wild.

Battery monitoring (I have this already)

500A Battery Monitor With Shunt

Renogy's 500A Solar Batter Monitor, A fantastic addition for your solar system, Featured with Battery Monitor With Shunt, battery shunt manager. Free Shipping

www.renogy.com

Understanding that I have a pretty crazy battery doing things not normally done with it, I assume have a stand alone monitor on the battery is a good idea. This seems straight forward to me and I believe this one will work. Please correct me if I am wrong.


Am I missing anything? Am I going to burn my van down?

Any thoughts are welcome.

 

[kernel]

Using the drive inverter? Wild.

 

[Flyingjibus]

I dont follow what you mean? Not using any inverter.

 

[dgjonesy]

I dont follow what you mean? Not using any inverter.

How do you run AC appliances from a battery without an inverter?

 

[BiduleOhm]

One of the unique things about this battery is it's ability to fool 120v AC devices into thinking they are on grid power. the engineer who worked on this battery (my cousin) has assured me almost any AC device I want to use in the van will most likely work just plugged into this battery

Wow wow wow, that's a bit quick to say.

First, pretty much anything with a motor will not work (and there's pretty high chances you'll burn the motor trying to make it work).

Second, what can work on DC (resistives loads like kettles and SMPS based devices like laptop and phone chargers for example) will be undervolted (96 V instead of 120 V that's a massive 20 % difference).

On top of that if there's switches they are very likely to arc (as they are only designed for AC) and start a fire (or just be destroyed and not work anymore, and yep, that's the best case...).

In conclusion I'd say it's a very bad idea to do that.

 

[upnorthandpersonal]

this battery is it's ability to fool 120v AC devices into thinking they are on grid power

To add what others said: even devices that used to be AC direct and resistive load these days are no longer: they use electronics inside which means there is a rectifier somewhere to at least power some aspects of the device. Putting a DC load even at a similar voltage level as your standard AC can very well damage your device, or in the bast case, it just won't operate.

 

[Flyingjibus]

I hear what you are all saying and am not discounting it. I bring all those same issues up with the designers of the battery and they tell me that it works. Something to do with the unique chemistry or something. I don't know much about it, i just keep getting told to stop worrying about it. I know nothing with a motor is going to work.

The battery when fully charged puts out 116v so the under voltage thing is a concern but not huge concern.

But I'm not opposed to running an inverter , just can't seem to find one that will accept 116v dc except grid tie stuff.

Can someone expound upon why everything i watch on youtube says not to use the power out on the C.C. to run anything?

Doesn't the controller need to see a load ?

I can wire that step down off the battery if i need to, but I don't understand why? Does my system running at 96v change anything about that ?