New controller? Looks like it was added today.

Hi Westend,

Great idea!

My water heater cycles once every four hours for 15 minutes once it has reached full temperature. When the battery bank is full, I do deliberately turn on the heater to continue to harvest solar. I also run it on electric when driving down the road.

I find, that the water, after sitting all night is still warm enough for hand washing in the morning.

westend wrote:
I was thinking of using the diversion load to heat the water in my fresh water tank (I have a steel tank installed inside). The heated water in the Winter would be passively heating the interior.

"How is that $30 30 amp PWM testing out yet for you? Or is it still too cold, wet and dark tor wire it in and see how she works? Mine arrived, and it's a big 'un to be hanging on the wall with that large display. "
----

Only tried it a little to see how to work the display buttons etc. Seems all right except the volt reading is reading low by 0.2v, so I have to apply that error when looking at it. No biggie.

Also the adjustment for stop charging or float voltage is wonky but also consistent so just allow for it. On mine, to get it to stop at 14.8 you have to set 14.4.

Once battery voltage reaches your setting of say 14.8 it stays there, which is what I want. If you want it to drop in voltage for Float after doing some time at 14.8, you can just set the voltage to that.

I won't know for a few weeks yet how the ammeter and AH counter check out until we are set up doing actual solar while camping.

Not cold wet and dark here! The yellow Daffs look nice under the mauve Magnolias next to the plum and cherry blossoms.

BFL13 wrote:
This says it is "built" in Arlington, Washington. (not that I care if it is built in the States or in Peru --sorry about that! :) )

http://www.wegosolar.com/products.php?product=MidNite-MPPT-KID-Solar-Controller-30A

Horribly expensive! $400 for a 30a controller. My Solar30 does 30a and cost $34. PWM though. Oh well.

Reminds me of when a Canadian company got banned from selling peanut butter in the States. Turned out that the US Govt required that nobody was to under-cut American peanut butter sellers, who had to pay $10 a unit from US peanut growers. (Goober peas?)

The Canadian company was buying peanuts at $4 a unit ("world price", not "USA price") from Argentina, so they were able to sell for less.

In steps the US Govt to "protect Americans." Hooray! Except not the American shopper who had to keep paying $10 instead of $4 for peanut butter. The Americans who got saved from those nasty Canadians by their grateful government were the peanut farmers who were able to keep their price at $10.

How is that $30 30 amp PWM testing out yet for you? Or is it still too cold, wet and dark tor wire it in and see how she works? Mine arrived, and it's a big 'un to be hanging on the wall with that large display.

If you have all that spare solar doing nothing just get more batteries to hold the sunshine overnight until you can use it.

In the summer you have low daily AH draw with not much furnace or lights on, but this is also when you get the most from the solar. That means if you have enough solar for winter , you have too much solar in the summer. Also your battery bank has more capacity now that it is warm out. It is all backwards, life is not fair! :(

You need a summer activity that can use up all that extra sunshine. Maybe leave a fan on all the time, instead of having the furnace on like in winter, since it is so hot out. A 12v hot tub next to your 12v beer cooler?

My diversified load is the trailer. Every light, fan, TV, even the furnace is covered by the panel once the battery hits float. Setting up the hot water heater would cost more than I'll use in propane for quite a while and as mentioned, it wouldn't be usable at normal times.

I was thinking of using the diversion load to heat the water in my fresh water tank (I have a steel tank installed inside). The heated water in the Winter would be passively heating the interior.

pianotuna wrote:
Hi Almot,

Once the batteries are full, I'd prefer to not wasted the potential solar harvest. I'd use it for powering a water heater element. Not an essential addition--but why not do so?

We only need hot water first thing in the morning (when we also do the dishes from last night) so if the solar did heat up some water it would be cold again by morning---a waste.

Luckily we can use the solar for things that very evening, like watch TV powered by another storage device---a battery! :)

Ok, seriously, what can you do as a diversion in the afternoon that you can use before it is gone? We don't need to be a farmer and pump water up into a big tank overhead and then get it back down by gravity as needed. Must be something.

Only trick I have found is use the laptop on its own battery in the morning, not off the inverter. Then recharge it in the afternoon using the spare solar.

Piano Don - Ok, I got it. There are probably as many solar scenarios as there are solar users. My trick is to charge the laptop and vacuum, when batts are full. DC water heater is too much work.

Hi Almot,

Once the batteries are full, I'd prefer to not wasted the potential solar harvest. I'd use it for powering a water heater element. Not an essential addition--but why not do so?

BFL13 wrote:
I still don't follow how you can tell how much of that daily draw (as seen by the solar controller) was done by solar using spare solar in the afternoon when the batteries didn't need it all.

I meant - to know daily draw of all the loads. Say, controller shows 60AH harvest in the evening, and status "Full", i.e. it went into Float - which I set very low at 1%C - and remained there most of the afternoon, and my usual daily consumption is 40. Doesn't matter how much of those extra 20 went into battery to bring the yesterday's 90-something SOC to ~100%, and how much into extra hour of laptop or cordless drill that I needed suddenly for some odd hole. The batteries were full. It's more difficult to tell the SOC when it didn't reach Abs, but this seldom happens.