Tell me what I need!

[kyonu]

Checked out the blog and though it has a lot of good information, boy does he need more paragraphs.

 

[TucsonAZ]

There is no such thing as "Modified Sine Wave", it's actually a modified square wave where they just add an additional square step to it. Here's a video to put it into a visual context, keep in mind that anything outside of the pure sine wave 60hz wave is wasted in modified square wave.

 

[akrvbob]

Other than a microwave, everything I own works just fine on a MSW and nothing I own has ever been damaged by one. And that's after 13 years of using a MSW for everything.
Bob

 

[TucsonAZ]

"Works just fine" could also be applied to drinking river water to survive, I'm not saying it can't be done, I'm not saying you won't be hydrated I'm simply saying it's dirty water just as modified square wave is dirty power. Is it worth the risk?

It's like using a PWM charge controller versus a MPPT, by the time you factor all things in, you reach a point of not really saving at much as you think.

Microwaves, clocks, many motors, fluorescent lighting won't do well and sometimes simply won't work with MSW, dimmers and rheostats won't work. MSW also struggles to keep up with surges the way a SW would be able to so your compressors will start but not the way they're intended to.

You may get humming in some items depending on your hobbies, I'm far too into radio and electronics to be able to use with MSW.

So you can use it but remember, you still have to spend money to buy one, I will go see what the one I have is and report back to you.

 

[blars]

Some loads are less efficient with MSW, many others are equally efficient. Without testing, I could not tell you which is which for sure.

 

[kyonu]

So as to alleviate any potential problems, would it be best to just go for Pure Sine Wave with the additional up front cost, with an MPPT charger? Parasitical load might be a bit higher, but I'd rather get quality and avoid problems.

 

[akrvbob]

You for sure want to buy a MPPT, it will pay for itself.

In 13 years I've had no problems with a MSW. If ZERO problems is too much potential problem for you, then be sure to get a PSW.

Now, there are some things that MUST have a PSW, especially medical devices. Do you have any of those? Do you have any reason to think you have any of those?

Because the great majority of items are fine on a MSW but a very few aren't, I'm going to start a thread asking for reports of people who have had items that worked badly on MSW. that way we will have actual facts not speculation.
Bob

 

[kyonu]

That's a good idea Bob!

I do not need any of those devices. Closest thing might be a TENS machine, but since the lady is becoming a massage therapist we no longer need it! Possibly a nebulizer, but I doubt that is a large enough device to need PSW. I'll look into the MSW you mentioned.

 

[TucsonAZ]

I'm going to bow out of this one saying you now have more than enough information to make an informed choice. I know guys that swear their square wave works perfectly fine and it will for many things, they're even less costly than modified square wave.

As a single dad on disability, I couldn't afford MSW, it just isn't worth the risk for me nor the exposure to the EMF they emit but hey, I won't even hold a cell phone to my head so maybe I'm just overly cautious.

 

[kyonu]

Okay, so I did extensive testing on my entire work setup. In 7 days (starting Friday morning last week, through Friday night this week) it reached 7Kw. That's only 1,000 watts a day (the WHOLE day) for an entire week, which is a lot less than I was guessing before. Since i will be lowering that throughout my time, I will budget about 750 watts for my work stuff, per day. And that's with printing about 5 times this week (which is highly uncommon.)

So with that in mind, I think Bob is right. I will pick up 3x Kyocera 250w panels, four 125ah 6v batteries, probably this kit here.
EDIT: Are Renology panels the same as Kyocera? Amazon has good deals on them, and when I browse Kyocera, Renology comes up. I was thinking I maybe don't need a full 750 watts, but maybe 600 with 6 100w panels (would be cheaper.)

Any best buy's on MPPT? I was thinking about THIS ONE, as Bob suggested.

I'm looking at 1500 watt inverters, and so far THIS ONE is on my list since it has decent reviews, and is still Pure Sine. Any comments on this brand or unit?

Now, I need recommendations for all the little in-between stuff. Solenoid? Fuses? Cables? Anything else?

Thanks!

 

[SternWake]

Proper cabling between the batteries is more than going to the autoparts store and buying their steel ended ring terminals.

Here are some steel ring terminals I cut off and replaced with brass. They are sticking to a magnet. You do not want steel ring terminals. They make a highly resistive connection prone to failure.

The following company can make custom battery cables with quality connections using top of the line tinned marine cable.

http://www.genuinedealz.com/custom-cables

They also sell lots of other quality parts you will need to build your electrical system.

The importance of Proper cable terminations cannot be understated. At best, Poor terminations cause bad performance, at worst, Fukushima.



Hydraulic crimpers still require some skill to do properly

 

[kyonu]

Thanks for the heads up! Will definitely look at this site.

Assuming the setup I mentioned before, which cable would be best for this setup? I've looked through the different cables that they offer, and I'm not sure which gauge is required. But, I did find that it has a maximum amperage, but not a minimum. Do you find losses in cables that are too big?

 

[Optimistic Paranoid]

Thanks for the heads up! Will definitely look at this site.

Assuming the setup I mentioned before, which cable would be best for this setup? I've looked through the different cables that they offer, and I'm not sure which gauge is required. But, I did find that it has a maximum amperage, but not a minimum. Do you find losses in cables that are too big?

From the point of view of electricity, there's no such thing as a cable that's too big.

A cable can be too big only from the point of view of your wallet. Eventually, you reach the point where the extra size isn't doing enough to justify all the extra money the big cable is costing.

Once you get to a wire size where there is only a 1% voltage drop, you're golden. Any wire bigger than that is a waste of money.

Regards
John

 

[Zil]

Don't lose sight that average watt usage does not indicate what you need for available power. You need enough to supply the momentary needs. Such as motor start up loads. Or k-watts needed for a few minutes per day or hour. 10kw for only one minute looks small averaged over a week.

 

[highdesertranger]

as usual good advice from everybody here. I will add one thing stern mentioned the steel terminals on battery cables. you have to watch this on the smaller crimp terminals also. lots of them are steel(iron) also, especially the cheap ones. I have gotten strange looks from the guys at auto parts stores when I take a magnet in to test them. harbor freight is a good example all of theirs I tested were iron. highdesertranger

 

[kyonu]

Don't lose sight that average watt usage does not indicate what you need for available power. You need enough to supply the momentary needs. Such as motor start up loads. Or k-watts needed for a few minutes per day or hour. 10kw for only one minute looks small averaged over a week.

You mean using the house battery as the starter battery? What might use 10kw for a minute?

 

[SternWake]

as usual good advice from everybody here. I will add one thing stern mentioned the steel terminals on battery cables. you have to watch this on the smaller crimp terminals also. lots of them are steel(iron) also, especially the cheap ones. I have gotten strange looks from the guys at auto parts stores when I take a magnet in to test them. harbor freight is a good example all of theirs I tested were iron. highdesertranger

Good point HDR. I once got some HF butt splices and put the 10-12 gauge ones on the 12 awg wire on my 25 amp charger. I'd pulled the plastic insulation off, made some beautiful crimps, used heat shrink, and the first time it passed 25 amps I smelled them overheating. The butt connectors were so hot they burned my fingers.

I went and threw out every HF connector i had bought so I would not waste time or worse using such an inferior substandard product.

I've been doing more soldering anyway now that I have a 60 watt Iron. 25 watts on wire thicker than 14 awg is almost pointless.


-------

The starter motor( engine) can pull 250 amps
250a x 12.6v = 3160 watts. Other things like fridge compressors or microwaves might draw 3 to 4 times their average running current, on start up.

Don't discount Peukert or inverter inefficiency. Add 15% minimum for inverter inefficiency and Peukert is a bit more complicated. But if you are running a 60 amp load, and run it for 30 minutes on a hundred amp hour battery, you do not have 30 amp hours left.

The higher the loads the more Peukert steals from the overall capacity of the battery bank.

http://en.wikipedia.org/wiki/Peukert's_law

 

[kyonu]

Great info fellas! Should I worry about the engine using the house batteries though? If they are separated, shouldn't I maintain them individually?

Also, so far, my amp draw is less than 20 amps. Even if I used my fridge on battery 24/7, my amp draw would still be under 25. I don't think I need to worry about a 60 amp burst like that (that I'm aware of). I think I will have to do some math on my cables based on my total amp draw at the end though.

 

[SternWake]

The house batteries can be used to start the engine, if wired to be able to do so. There are so many ways to keep engine and house separate with engine off and together with engine on, this there is no one answer.

I like keeping the engine battery fully charged. I've moved loads like the Stereo and most stock lighting to the house battery, greatly reducing the chance that the engine battery can be discharged inadvertently. I don't have a key fob for the door locks, so the only parasitic load on my engine battery is the engine computer which is barely measurable with the tools I have.

Flooded batteries can self discharge 15% a month, so long times parked and you should bring the engine battery into the charging loop with the house batteries and remove it again once the controller/charger goes into 'float' stage. But you do not need to do this every day. You can, if you have enough solar harvest, but if you are short, then don't share with the engine battery, feed the house all that is available from the solar.
Some Solar charge controllers will divert a portion of the charging current to a load, like a light or the engine battery, once absorption/acceptance voltage is reached on the house bank and there is extra current available over what is needed to hold the house bank at 14.x volts. I really wish I spent the extra 30$ for that BS sb2512ix controller, as it also has provisions for a battery temperature sensor, in addition to that extra 'load diversion' feature.

Some devices designed to automatically combine batteries with engine running and separate them when not are dual sense or single sense.
Single sense combines the batteries when only the engine battery receives charging voltages
Dual sense combines the batteries when either battery is receives charging voltages.

I recommend those with solar go single sense if choosing this type of isolator/combining device, and be mindful of the engine battery if parked for a long time without driving, and send it some love every so often. This can be done with a short jumper wire across the device. Jumping the starter battery from house bank can be done with this same method, but the Jumper wire gauge should be 4 awg or thicker, and give it a minute or two before cranking the starter.

 

[kyonu]

Instead of trying to jump the battery every so often, wouldn't it make more sense to start the engine for a few minutes once a week or so? Wouldn't the alternator bring it back to full charge?

Sorry for all the questions, you guys are just so darn helpful!