Oct 31, 2016 Update: Telsa just recently announced the Powerwall 2, and we’ve started getting questions on it too. Here’s our take on it:From an RVers perspective, I don’t see any practical difference between the PowerWall 1 and PowerWall 2.The big change with the PowerWall 2 is that the inverter is integrated and not a separate box anymore. This integration might actually make it harder to merge into an RVs systems – but no detailed technical information has been made available at all.The cost per KWh is great, so I imagine some enterprising hardware hacker might find a way to integrate this into an RVs system at some point down the road once they ship next year. But for now, it really isn’t very interesting for most of us mobile folks.
Ever since the rumors hit last month about Tesla releasing a residential battery, we’ve been getting questions about it…
Might this at last be the RV battery revolution we have been waiting for?
Tesla Motors last night at last revealed some details – announcing their first product that is not an electric car: the Powerwall Tesla Home Battery.
As Tesla describes it:
Powerwall is a home battery that charges using electricity generated from solar panels, or when utility rates are low, and powers your home in the evening. It also fortifies your home against power outages by providing a backup electricity supply. Automated, compact and simple to install, Powerwall offers independence from the utility grid and the security of an emergency backup.
The $3,000 7kWh Powerwall model intended for “daily cycle applications” weighs just 220lbs, but offers the equivalent usable energy storage capacity of a massive bank of 1,000Ah of lead acid batteries – roughly four huge 8D’s. And for even more capacity, multiple Powerwall units can be chained together.
And thanks to Tesla’s liquid thermal control system – the Powerwall batteries are fully functional from -4°F to 110°F too.
All backed by a ten year warranty, with shipments beginning later this summer.
Wow – sounds perfect for an RV, right?
Not so fast…
Powerwall = Too Tall
The first problem to consider is the size.
True to its name – the Powerwall is designed to mount… on a wall.
Ideally in a garage, or on the side of a house.
Though it is only 7.1″ deep, the Powerwall is well over 4′ high, and nearly 3′ wide. Not even the largest bus conversions have the bay height to mount a Powerwall down below. Unless you get crazy and mount it on a living-area wall, or the rear cap of your RV, a Powerwall just isn’t going to fit.
And though it is not confirmed – presumably due to the liquid thermal management system, the Powerwall “must be wall mounted” and not installed flat.
The other catch is that the Powerwall battery operates internally between 350V – 450V, though it presumably can down-convert and output 48V to interface with a residential solar inverter.
But 12V or 24V output is extremely unlikely – making the Powerwall nearly impossible to interface with typical RV power systems.
And the final catch for using a Powerwall to power an RV…
Tesla will only be allowing installation by licensed and certified installers. It may be a while before hackers and hobbyists can even begin to start getting creative shoehorning the components into an RV friendly installation.
But still… This is exciting technology.
And I’ve already tweeted at Elon Musk asking him to consider releasing an RV-friendly version. Hopefully he is listening.
Posts in this Series:
Promise of Lithium #1: Lead Acid Battery Downsides
Promise of Lithium #2: Lithium Ion Battery Advantages
Promise of Lithium #3: Cost Analysis (including our part list)
Boosted Electrons = Better Views (why a boosting inverter rocks!)
7/2013 – Living in a Parking Lot – Practical use example of our LFP & Boosting Inverter
2/2013 – Lithium Dreams, Lined With Worry? (Response to Boeing Dreamliner Battery Fire)
8/2012 – Our 1 Year Update on our Lithium System
8/2011 – Build Notes: Lithium Ion Battery Success!!
8/2011 – Build Notes: We Built a Lithium Ion Battery Bank
8/2011 – The idea is born: Inverted Intentions (August 2011)