backchannel: slamming one’s own hand in the solar door

The normal path to building a functional solar configuration is something like:

  1. read to see what’s possible
  2. crunch the numbers to see what it’s going to take to run the loads you want to run
  3. read more, ask for advice
  4. re-crunch
  5. agonize over component selection, pore over specs and documentation
  6. start building the system
  7. test, alter, improve
  8. enjoy power from the skies

The path to frustration and wasting money is:

  1. have fantasies about hashtag-vanlife
  2. start buying shit at random
  3. get offended/frustrated when it doesn’t end well. Bonus points: call the gear you don’t understand “junk” or blame others for your foolhardiness.


My plan is to put on 400 watts of solar, have 200 amp hours of lithium, and size my usage accordingly. This is backwards to most calculators, but I figure it’s the logical way to do it. IE, if you find something you are running is taking more power than you have available you need to look at the possibility of more efficient options, or using that item less. (emphasis added)

It’s backwards from what others are doing because there is no reasonable way to pick out gear if you don’t know what you need.

thus it begins

I just ordered $2300 in solar parts.

I can’t look.

we ask questions AFTER purchase, right?

What cooking device would you use on a van solar system? I have a 1200w inverter on 200ah worth of 12v lithium batteries.


the magic unicorns are uncooperative

Turns out the Renogy kit I bought has a shitty PWM CC in it

which, as it turns out, is somehow somebody else’s fault

Didn’t know MPPT existed. Still not sure what the difference is. Just bought a package deal. It’s not like I had anybody telling me what I should do at the time shrug

I’m not saying the PWM is bad. It might be fine; don’t know until we try. I’m saying the buyer needs to understand the gear and its function before buying it.

let’s not forget the lithium batteries

Wow, so they get damaged if they freeze?

OMG, dude. This could get very expensive, smoking $1000+ of new battery in an instant.

epitath (his words, not mine)

That’s what happens when you wing it and you don’t know what you’re doing.

Indeed, sir, that is what happens.

This fellow, having learned nothing is now offering advice on the subject. To quote Oscar wilde:

The brotherhood of man is not a mere poet’s dream: it is a most depressing and humiliating reality.


twitter comment thread for this post