Surfmobile Project

[surfcowboy]

Padre, only if you were going to drive it on electricity or power a rock concert.

The Powerwall is gigantic compared to what you need, but, it's the same tech as what Pono has built. Geek out on DIY Powerwalls and you'll see what I mean. There's also a ton of stuff on YouTube. People pulling cells out of old laptop batteries and hacking them together. Pono did it right, new cells, sized well, nothing crazy. Let me go see if I can get the specs on the Tesla for reference.

Update: The surfmobile has 180 cells in those packs. The Powerwall has 800 in the 10 Kw version!

[PonoBill]

Actually, a Powerwall wouldn't be the worst decision ever, especially if it replaced a gas generator as well as lead-acid batteries. The price isn't all that bad and the tech is great. The original 3.5 KW one would be especially good, the current 10KW is a bit much, but not crazy. a typical maximum RV load is in the 3 to 5 KW range. Typical gasoline, diesel or propane RV gensets are 5-6KW. The biggest problem is getting one. I don't know what the wait is now, but last I heard they were reserved about a year out.

The battery I'm building will actually be 360 cells eventually, and I decided to split the 180 cell 12V battery into three 60 cell 12v batteries--both for reliability and to reduce the cost of the BMS system. A 4s 300amp LiFe BMS is expensive and the wait to get one is long. A 4S 100 amp BMS is ridiculously cheap (about 15 bucks for a good one) and I can get them in three days.

There's a large and very whacky DIY powerwall community. If you can sift through the nonsense, there's lots of good information. Unfortunately, there are also a lot of idiots who will soon be burning their house down.

[surfcowboy]

Pono, I forgot the smaller one. Wouldn't charging that thing take forever with any solar system you can carry? Would you just use it for short periods and plug in to charge?

The DIY thing is pretty crazy, I agree. Seems like a lot of potential for disaster there. The YouTubers also really seem to do a lot of, "well, I tried that and it didn't really work " lol. Maybe not the best place for wild experiments?

[PonoBill]

Pretty easy to carry 600 watts of solar panels. With an MPPT charge controller to optimize charge rates and being careful about shading that's about 2-5KW per day assuming full sun and optimal angles. And of course, there's going to be a charger for when I get to plug into something, and I have a 5KW genset that will charge the batteries at a furious rate whenever I need to run it. For that matter when I'm driving the 160 amp engine alternator will divert a few amps.  If we're parked for any length of time I'll set the solar panels at a good angle.

I have some good 12VDC linear actuators kicking around from the shaping stand experiment, I might work up something automatic. I drew up a pretty slick rack/panel aiming system and roughly designed the electronics for aiming and automatic stowing when the engine starts (meaning I wrote some pseudocode for the software).

Everything is tucked away for the winter--headed for Maui in a couple of weeks. I have to say I hate to leave this project. I'm having fun with it. I've got the kitchen cabinets framed. They're going to be very cool. The interior is going to be shockingly sparse. We decided space is better than storage. we'll see how that works out. Dumping 1800 pounds makes for a pretty nimble RV. It's noticeably sprightly.

[surfcowboy]

Love it man, I know it's got to be hard to leave it.

I thought you were ditching the generator. If you've got that and solar, you're rock solid then.

Gonna be a nice rig for sure. Enjoy Maui, I think Headmount's getting lazy without you around. He seems to sit a lot these days.

[johnysmoke]

Very cool. Hope it comes finished with some tikis, a fire pit, and an exterior wet bar. I hope you get many miles out of it.

[stoneaxe]

Very cool. Hope it comes finished with some tikis, a fire pit, and an exterior wet bar. I hope you get many miles out of it.

Now I know what my contribution can be.....make a spot for a Tiki bro......

[PonoBill]

Among other stuff I worked out integration of a simple wireless LED controller for managing the lighting in Fritz. Most of the interior electrical stuff will ultimately be IOT via phone and/or Alexa. The wiring mess in the current configuration is just hideous. A rats nest of old wiring in use, old wiring abandoned, new wiring with halfass routing, and it's all just plain ugly. I can't stand for that. Everything will be simple and serviceable. The old Jaguars I occasionally worked on had wires everywhere, but everything was in elegant looms, carefully identified, and beautifully organized so you could repair stuff. New wiring is multiplexed, which is even neater, but hard to service or repair. The next stage is wireless control, with only power leads. Bitch to service unless you're up on embedded systems programming. I am, but one stroke and this will all be unserviceable. I better get it all on github.


What's really funny is that playing the movie runs alexa through the speakers, and she does the commands. It's like an echo echo.

[Tom]

You could prerecord all the comands, put them in a sound box and have an app that selects the comand that speaks the comand.......

[PonoBill]

You could prerecord all the comands, put them in a sound box and have an app that selects the comand that speaks the comand.......

I think that's how the current wiring works.

[SupPadre]

Saw this and thought of Pono's project.

[all~wet]

I saw Pono's project and envy aside.. couldn't help but think of Stripes and the infamous EM50 project.