Capacity Testing and 20 HR Rating

Salvo wrote:
Like a converter, the microwave takes power from an ac source only during peak amplitudes of the sinusoidal waveform. That means the ac current is quite a bit higher than you think. That also means the ac line loss will also be more than you think. It all goes to hell in a handbasket.

Just about everyone uses the Watt setting on a kil-a-watt meter when measuring power. That's the wrong setting. Use the VA setting to get true power.

jrnymn7 wrote:

How would one go about that? And is it a combination of poor efficiency and line loss, or is one simply the result of the other?

Ah, yes... guilty as charged. I should have known better. Next time I will use the kill-a-watt meter, in VA mode, and compare to the Inverter's watts readout, and the Trimetric's amps readout.

And I've never tried using the kill-a-watt's PF function. Will it actually calculate, accurately, the PF of whatever is plugged into it?

pianotuna wrote:
Hi,

It may be a problem in the summer time--but that is why I use a temperature probe on the battery bank to reduce voltage. The solution is to pay a bit more for a controller.

jrnymn7 wrote:
Don,

I agree! And thus my concern about using the solar30. At what voltage setting would constitute overcharging? Is it o.k. to have the bank at say 14.6v for several hours past full, for example? I'm guessing, as long as excessive gassing isn't occurring, I'm good to go?

Both the tracer and solar30 have temp comp... but how well they work is yet to be known. I guess I'll know soon enough. I still think the biggest issue, though, is the battery cabinet overheating. There's about an inch all around each battery and about two inches above, but hot air gets trapped in that 2" space above. Installing a 'chimney' vent was just not an option, so I need to get a 3" x 10" x 4"dia. 90 degree angle boot installed in there, and a 12v fan, in order to exhaust the hot air out from the tops of the batteries. I may also need one or two fans to force air in and around the bank on those really hot days.

A few years back, I was working in Saskatchewan, at a potash plant. It was only about 85F, but my partner, from Manitoba was pouring with sweat... while I was just warming up :). A few weeks later, I was wwoofing at a greenhouse just outside Saskatoon. It was about 87F and the folks there couldn't believe I was working in the sun with a long sleeved shirt on, while they were hiding inside, in the air conditioning! That week, first (or second?) week of June, it was 106F in south-western Ontario (well above anything I had ever seen). I have a feeling we may see those sort of temps here, this year, seeing as it's already been hovering around 80F a few days, off and on.

Hi,

It may be a problem in the summer time--but that is why I use a temperature probe on the battery bank to reduce voltage. The solution is to pay a bit more for a controller.

jrnymn7 wrote:
Don,

I agree! And thus my concern about using the solar30. At what voltage setting would constitute overcharging? Is it o.k. to have the bank at say 14.6v for several hours past full, for example? I'm guessing, as long as excessive gassing isn't occurring, I'm good to go?

Like a converter, the microwave takes power from an ac source only during peak amplitudes of the sinusoidal waveform. That means the ac current is quite a bit higher than you think. That also means the ac line loss will also be more than you think. It all goes to hell in a handbasket.

Just about everyone uses the Watt setting on a kil-a-watt meter when measuring power. That's the wrong setting. Use the VA setting to get true power.

jrnymn7 wrote:

How would one go about that? And is it a combination of poor efficiency and line loss, or is one simply the result of the other?

Mex,

So it is easily do-able... good to know. I'll wait and see how things go with my usage and 280w solar set-up this summer. I may be over-estimating my daily haulage, like landyacht has pointed out regarding us 'solar newbies' :). And in the past, I have avoided using the a/c, just to save on consumption, so that may change as well.

In the end, I'll likely end up going with the Tracer full time, because of it's user-ability, and keep the solar30 as a back up. But I'm still eager to do some comparisons between the two, under various conditions... But what we really need is an eco-worthy-tracer-morningstar showdown :)

Several hours "past full" in daily format at 14.6 is too much in my opinion. i forgot what batteries you are using, but this is an early demise formula for 5% antimony batteries. Antimony poisoning. Wouldn't matter if it were infrequent but on a daily basis this becomes a definite concern.

On eBay you will find interval 7-day 12-volt timers. Their quiescent power requirement is impressively minimal. By coupling the timer to a simple to connect 40-amp solid state DC/DC relay (cheap!) you can control an impressive load or charging source. Set the off time, say, at 1430 hours, and enable time at 0700 and you have a hand's off timer circuit.

Connection, and operation of the timer and SS relay is a piece of cake. Both are reliable and the SS relay uses MOSFET transistors with voltage drop measured in millivolts.

Don,

I agree! And thus my concern about using the solar30. At what voltage setting would constitute overcharging? Is it o.k. to have the bank at say 14.6v for several hours past full, for example? I'm guessing, as long as excessive gassing isn't occurring, I'm good to go?

Hi,

Set the charge controller to prevent over charging. I believe you are "over thinking" this. The only time I look at the charge display on the 3024di is when I want to know if it is working in low light. Solar ought to be 'set it and forget it' as much as possible.

jrnymn7 wrote:
Mex,

This is the dilemma I find myself in. When working 9 hr days, mon-thurs, I may or may not be able to run out to the bus and turn off solar charging. (And quite frankly, I don't want to have to plan my days off around battery charging, either.) So if daily usage is such that the bank is full around mid-day, it will continue to 'float' at 14.4++ volts for several hours. My thought was to drag out solar charging, by using just one panel (140w) instead of two (280w), at such times. But either way, the bank will be in that high 14's range most of the day. So I'm wondering if there is a suitable 12v timer that could be set to disconnect panel power to the controller? Or is it not worth worrying about?

Mex,

This is the dilemma I find myself in. When working 9 hr days, mon-thurs, I may or may not be able to run out to the bus and either turn off, or lower the voltage on solar charging. (And quite frankly, I don't want to have to plan my days off around battery charging, either.) So if daily usage is such that the bank is full around mid-day, it will continue to 'float' at 14.4++ volts for several hours (using the solar30 pwm). My thought was to drag out solar charging, by using just one panel (140w) instead of two (280w), at such times. But either way, the bank will be in that high 14's range most of the day. So I'm wondering if there is a suitable 12v timer that could be set to disconnect panel power to the controller? Or is it not worth worrying about?

Of course, my other option is to simply fore-go the solar30, and use the programmable tracer mppt, which should drop into real float when near full.

Hi jrnymn7,

Circuit Breakers take ages to flip off compared to a fuse. For that reason it may be better to undersize a breaker.

Thicker wire can help. So can 12 volt jars.