Parts of an electrical system - what would I need?

[markopolo]

Originally Posted by MegA

....When you're talking about 1000-1200 watts for the inverter do you mean the continuous usage? On most inverter specs I'm seeing 2 figures, a "continuous" and a "peak." The peak is usually twice the other figure.....

That would be continuous. 1200 watt would give a bit more cushion and I'd go with that size.

Wilton's article is a good read: http://windsurf.mediaforte.com/roadt..._inverter.html

I wouldn't connect the inverter to the engine battery like he did. His inverter was used specifically for the microwave and he always ran the motor when using it. You'll be running other items off your inverter. I would suggest running the van engine when you use high amp draw appliances like the microwave though. I'd probably run the engine for 10 minutes if I used the microwave for 5 minutes.

[MegA]

Originally Posted by markopolo

Wilton's article is a good read: http://windsurf.mediaforte.com/roadt..._inverter.html

I wouldn't connect the inverter to the engine battery like he did. His inverter was used specifically for the microwave and he always ran the motor when using it. You'll be running other items off your inverter. I would suggest running the van engine when you use high amp draw appliances like the microwave though. I'd probably run the engine for 10 minutes if I used the microwave for 5 minutes.

Thanks for the tips. I'm glad you don't recommend his setup - he lost me about a third of the way down the page. (I'm just starting to figure out this amps/watts/voltage thing; anything more than that is too much at this stage.)

I'm currently looking for a smaller microwave with lower wattage; even if I knew what the wattage was on mine, and I can't find any info anywhere (maybe it's on the bottom; haven't tried turning it over yet), it's way too big. When I first read that I could maybe have a microwave I got all excited - until I looked at my budget. Then last night it occurred to me to check the local Craigslist for stuff and there's at least one possibility there. Plus there are lots of thrift shops here in Denver and there are usually at least a couple of micros at those. I'm wondering, though - is there a way to check wattage on a device if it's not labeled? Would that involve purchasing something to do that?

I'm not having a lot of luck finding inverters locally - actually that's not quite true, I can find lots of little ones, it's amazing how many different kinds there are. There aren't a lot of larger capacity ones though, or maybe I just can't find ones with good prices; right now it looks like I could spend more on the inverter than the battery. I'm going to keep looking but if anyone has any suggestions for chain stores that might carry them that would be great. (I don't belong to any of the membership stores.)

Meg

[Mike]

I got 2 400W inverters at Batteries Plus for $40 each. Both could be used in cigar lighter outlets or connected
directly to a battery. I've also seen inverters from 100W-3000W for sale at at Advance Auto and Autozone as
well as B-Plus. They sometimes go on sale and you can get some priced quite reasonably. Used electronics
always scares me a little, because you have no idea what it's been through, or even if it's been tampered with,
but that's just me.

[MegA]

Thank you, Mike! I'd checked out Batteries Plus and the highest they seem to have is 600w. But it never occurred to me to look at auto parts stores (even though now it seems obvious). AutoZone has a store within walking distance of where I live and according to their website they have a 1000w in stock for $100. Advance Auto (also within walking distance) does too but it's twice the price. I also checked out O'Reilly (that used to be Checker). Their 1000w is a pure sine wave so it doesn't compare with the others; it's $329. But they have an 800w for $80. That at least gives me some options.

It seems some of those stores also carry deep-cycle batteries so maybe I can get them both at the same place. Today I took a trip to the local (not very close) super Wal-Mart to check out a bunch of things and got a bit of an education on battery prices that I thought I'd pass along to any other newbies reading this: There's an extra charge if you don't exchange one! It's got something to do with recycling the core and Wal-Mart's is $10, but I see that AutoZone also has one (theirs is $12) so maybe it's a standard thing or even mandated by law (I was told recycling the core is). I didn't know this and now I'm wishing I hadn't let the guy who bought the wheelchair lift take the old battery with him; it just seemed like a good idea at the time, I wasn't sure what I'd do with it. So I'll have to pay a bit more for this battery. Oh well; another thing to add to the "now I know better" list.

Meg

[Mike]

I've been trying to figure out a quick and easy way to install a high capacity inverter in our van (for a while now)
so we could make coffee without firing up the generator or plugging into shore power. I believe the answer is
there is no quick and easy way to do it. However one of those 2 auto parts places had an inverter (>1200W?)
sale last summer, regular price was around $150, on for $99. It came with it's AC outlets on an extension
cord, and so could be mounted physically near the battery, but could be used to plug into from some distance
\way. It might work for you as you don't have all the built ins I have to deal with. It was made by Peak, and the
model number was PKC0CF. It was on display in either Advance Auto or Autozone, and it came with battery
post cables and clamps, and it had 2 AC and 1 USB outlets on a block at the end of a cable which was about maybe
12' or 15' long, like having a built in extension cord.
Hang on, I found it. It's online here at Advance Auto for $99. I have no idea how good it is, but it comes with some
warranty I'd think.
http://shop.advanceautoparts.com/webapp ... ent=value4

This might work for you?

[MegA]

Hmm... An availability search shows it's at the store I can walk to. And that's a good price for 1200 watts. Right now I'm trying to figure out if I'd need to have the outlets that accessible; the space isn't that big and it *is* really open - at least so far! (Is that why you're having trouble with this in your Roadtrek?) I'm going to be really limited in what I can run with whatever battery I get - it looks like the space will hold only a group 24 - so I was figuring I'd just keep the electrical stuff close enough to plug in directly so I can monitor it better, and unplug when I'm not using it. But if I have to use an extension cord I think I'd rather use one that's attached to the inverter; I've had many different ones over the years and they really seem to vary in quality.

I thought I read somewhere that inverters (or maybe converters?) have to be physically close to the battery. Is that right? If it is, I can see how attached extension cords would be useful.

This is a "while supplies last" thing so I'll try to get down there either today or tomorrow to at least check it out.

I did stop at O'Reilly Auto on the way to grocery shopping. It looks like their group 24 would be about $72 with the core charge - not bad. But the salesperson didn't seem to know a lot about them and since I don't either I'm not sure I want to buy there; I'm afraid I'll end up with the wrong battery. They had only 2 inverters in stock; a small one to plug into the cigarette lighter and an 800w for $80.

The O'Reilly guy said something about not being allowed to put stuff in vehicles. At first I thought he meant he couldn't carry it out for me, which is a *big* problem since I can't lift it. But he said he could do that; I think maybe they're just not allowed to connect them. I've already asked my mechanic if they could do that and he said yes; the van is going in for a checkup on Monday so if I can get the battery before then maybe they can do that with the other service. I just wanted to pass this along to anyone else who didn't know. I suspect it's a rule with all the auto supply stores.

Meg

[Mike]

Originally Posted by MegA

Hmm... An availability search shows it's at the store I can walk to. And that's a good price for 1200 watts. Right now I'm trying to figure out if I'd need to have the outlets that accessible; the space isn't that big and it *is* really open - at least so far! (Is that why you're having trouble with this in your Roadtrek?) I'm going to be really limited in what I can run with whatever battery I get - it looks like the space will hold only a group 24 - so I was figuring I'd just keep the electrical stuff close enough to plug in directly so I can monitor it better, and unplug when I'm not using it. But if I have to use an extension cord I think I'd rather use one that's attached to the inverter; I've had many different ones over the years and they really seem to vary in quality.

Yes, the coach/aux batteries in my van are on the opposite side from where most of the electrical outlets and appliances would be used. They ran basic cables to the area, but not thick enough to run a higher capacity inverter from them, so I'd have to run some 00 gauge cables from battery to battery to some point nearer the driver's side of my van, where I'd actually need the power. It just got too complex, so I went with 2 smaller ones to run the small draw stuff and we fire up the generator when we need to for larger draws. Another option might be to use 2 6V batteries wired in series to run at 12V, if you could fit them into your battery box area somehow?

Originally Posted by MegA

I thought I read somewhere that inverters (or maybe converters?) have to be physically close to the battery. Is that right? If it is, I can see how attached extension cords would be useful.

Yes, because the amperage on larger draw loads will cause small gauge cables to heat up, and possibly melt/ignite, so you have to use larger gauge (physically thicker and heavier, so more awkward to work with) cables for longer distances between the batteries and the inverter. If you can position the inverter very close to your coach battery, the shorter the cable length allows smaller gauge to be used which allows for less voltage drop from the batteries to the inverter, so it's more efficient. Arguably, as I understand it.
I'm no electrician, though.

Originally Posted by MegA

This is a "while supplies last" thing so I'll try to get down there either today or tomorrow to at least check it out.

Have a look. Ask questions, but don't believe everything you're told. You don't have to buy anything yet. You probably should get a deep cycle battery installed and charging first. Besides, if it\s on sale now, and it doesn't sell, it'll be on sale again, or they'll stock something similar in the future. The manufacturers often have 1-800 support lines which usually are staffed with people who can answer the "techie" stuff. I should have bought one last August when they were on sale, I could have sold it and maybe made a few bucks if I found I couldn't use it. The small 400W inverters I bought were made by a company called Schumacher (like the F1 guy) and they seem pretty good so far, although we haven't road tested them yet. Hope to, sometime soon, maybe after Christmas/New Years. Maybe Schumacher has a larger capacity model that would work for you?

Originally Posted by MegA

I did stop at O'Reilly Auto on the way to grocery shopping. It looks like their group 24 would be about $72 with the core charge - not bad. But the salesperson didn't seem to know a lot about them and since I don't either I'm not sure I want to buy there; I'm afraid I'll end up with the wrong battery. They had only 2 inverters in stock; a small one to plug into the cigarette lighter and an 800w for $80.

I'd skip them, because of the selection and the lack of in store expertise. I found that last summer when I was shopping, that very few stores (AA and AZ as well) had much expertise on site at most locations, but all were very helpful based on their knowledge level (and mine???). I think you sound like you have enough of a basic understanding (like lots of us) that you'll probably be OK. Just always ask about return policy when you buy something, in case you do mess up and need to return something.

Originally Posted by MegA

The O'Reilly guy said something about not being allowed to put stuff in vehicles. At first I thought he meant he couldn't carry it out for me, which is a *big* problem since I can't lift it. But he said he could do that; I think maybe they're just not allowed to connect them. I've already asked my mechanic if they could do that and he said yes; the van is going in for a checkup on Monday so if I can get the battery before then maybe they can do that with the other service. I just wanted to pass this along to anyone else who didn't know. I suspect it's a rule with all the auto supply stores.

Meg

Liability insurance for installations probably costs a bundle so they just sell the stuff, but won't install. You could ask them
if they could recommend someone to do it. Sometimes they can give you an idea of wha it might cost, too.

[markopolo]

Interesting find Mike. The outlet consists of 2 AC outlets and 1 USB power port. The USB port gets power even when the inverter is off - very handy for charging things that have a USB connection. What is your guess for the 4th item on the remote outlet? Is it an on/off switch? Very convenient if so - inverters should be turned of when not in use as the draw anywhere from 1 to 2 Ah when powered on and not even being used. Peak recommends that a fuse be installed between the inverter and the battery. That is normal.

[Mike]

Aw, shucks, tweren't nuthin'.
re: 4th thing on remote. I can't recall whether it's a rest button or something, like on a GFCI.
I handled one in an Advance Auto somewhere in NYS last summer, and can't really recall.

I may get one if there are any left next trip south. I would have to bridge my current batteries with heavy cable,
to combine them in parallel for draw, then figure out where to put the inverter, so it's inside and away from the
weather. So that meant near the right rear quarter, or forward possibly in the toilet area, and then running the
remote would have been easy. It's the first 2 problems that made me decide to go with a couple of lightweights.

However, you are correct in that it's an interesting setup, with the AC/USB power on the end of a built in extension
cord. That was the reason I looked into this one, as we discussed a few months back. It eliminated running long
00 cables from the batteries to the driver's side of the van where the primary draws would be.
I'm thinking in hindsight, I should have mounted it inside the right rear storage area under that side's bench, and
cabled the heavy battery cables front to rear, and then attached the inverter through a small hole in the right rear
body floor or wall. Still, the issue is to connect the 2 coach batteries to get maximum power from my bank, and
that requires somewhere that I can get underneath the van for a few hours with some heavy cable and some
heavy connectors and crimping tools and clamps and so on, and so on.
Maybe next summer?

[MegA]

I did go and look at this inverter yesterday, but now I can't remember whether that's an on/off switch. I think it is. I was thinking the inverter would have to be off when not being used, so if it is that would be good - I wouldn't have to disconnect it.

I also looked at batteries there. This place does include installation with purchase; there was a sign posted in the battery section about that. I guess they've just included it in their liability insurance.

I was lucky; the person I talked to there has used RVs so he was familiar with what I was planning to do. He showed me two group 24s, one of which had higher aH; I thought each size came with only 1 amperage, so another lesson for me. He didn't seem to think the "smaller" one, with 75 aH, would be much good for me, especially if I'm planning to use a microwave - something about the initial load being too high? He said things with motors use more power at the beginning when the motor is first starting up. It did remind me of something I read once, about how it uses less power to leave a vacuum cleaner on than to turn it off and on again (depending on how long it's going to be running without being used, I guess).

Anyway - the "bigger" group 24 had 135 aH, I think. It would cost about $90 with the core fee. So altogether, about $200 for both (according to the salesman the inverter price is good until the end of the month). Doesn't sound like a lot but that's relative; the available funds are dwindling fast.

I've been trying to decide if I can just use my own microwave but am having trouble with that; there's no wattage on it anywhere (I think it's probably just rubbed off). I did some research online and there's a "boil test" you can do; according to that my micro is only about 650 watts, but - I'm in Denver which is 5,280' above sea level. I'm looking for another way to test it or convert the figure I got for altitude. Marko, should I start another thread for that or leave it here? So far I've tried asking on Yahoo! Answers but the one reply I got was way over my head.

Meg

EDIT: One more thing, about the initial load on items with motors - would that influence the inverter size I should consider, or does the "peak" setting they all seem to have cover that?

[markopolo]

You can keep expanding on this thread - it is all related.

Re: your microwave, did you look just inside the door? That is where the specs are on mine.

Batteries:



A group 24 just can't have an 135 Ah rating. It is not big enough.
Be aware of the RC rating on Marine or dual purpose batteries.
RC = Reserve Capacity
Amp-hours (20-hour rate) = RC x 0.60 (info from Interstate)
So a Group 24 with RC of 135 = 80Ah rating

[MegA]

Re: your microwave, did you look just inside the door? That is where the specs are on mine.

Oh.



Wow - it's 25 years old, that's great that it's still working.

I tried multiplying volts by amps, as you did with the monitor wattage, but I get 1296 and according to this page it's 600 watts:
http://www.panasonic.com/consumer_elect ... r=NN-6406A

I'm not sure about some of those specs, though. The measurements are close to what I get. But the weight - if it's really 40 pounds then I'm a lot stronger than I thought I was.

About the aH on the group 24s - that makes sense, it was a marine/dual purpose. I know there's another type, besides this and the standard "starting" battery, but I haven't been able to find any of those; maybe it's because of where I've been looking. The salesman yesterday said something about dual purpose being good for occasional starting but not as good for reserve as the others. (I'm probably using the wrong words here, I don't know the terminology.)

Meg

[markopolo]

Those specs are probably right. Almost 1300 input watts for 600 output watts. Some newer microwave ovens will be more efficient like 1100 input watts for 700 output watts. You have to size the inverter and battery bank based on the input watts.

[MegA]

Originally Posted by markopolo

...You have to size the inverter and battery bank based on the input watts.

Okay. So either the inverter we've been talking about wouldn't work or the microwave wouldn't work. That's fine; the micro is really big, I'm not sure where I would have put it. And the inverter is no longer on sale, and after my experience buying the battery there today I'm not sure I want to buy anything else from those people.

We have snow moving in tonight and since this van is so bad in the snow I decided I wanted to get the battery bought before the weather changed. (I can run lots of errands using the bus or just walking; the battery is too heavy for that.) Advance Auto looked like the best choice because the prices were reasonable and they had a sign saying "free installation." But the guy I talked to the other day wasn't there, and the person who helped me said - *after* he put the battery in the van - that he didn't know how to connect it. So now the van is at the mechanic's waiting for them to get around to it. Since I just kind of dropped it on them without an appointment I'm not sure how long it will take; I'm just hoping they'll have it finished before the roads get bad. And if they charge me I'm going to get in touch with Advance and ask for that money back.

All right, I'm done grumbling. I will say that we tried the group 27; it wouldn't fit, it was about a half inch too big. . So I bought the 24-3, which is the one I talked about before. With the core charge and tax it was $96.

About the inverter: I'm not sure I can manage one big enough to handle the input wattage on a microwave. So maybe a microwave won't be an option after all.

Meg

[markopolo]

Watch for sales. I was looking at the Walmart flyer today and see that they have a 0.6 cu ft Danby microwave oven listed at $33. Actually, it shows $38 reg price.

Here are the specs on a Haier 0.6 cu ft microwave oven from Walmart:





950 watts power consumption for 600 watt cooking power.

[MegA]

Thanks for the tip, marko - and all the research too I've also been looking on the local Craigslist and there are a lot listed there at some really good prices, like $10. Some have sounded almost exactly right for me - small ones used for dorms that have now been replaced with bigger ones. But most people don't know the wattage (just like I didn't).

I'll try to find the local Wal-Mart's sales flyer because it would be nice to have a newer (and more energy-efficient) one. There's a superstore about 5 miles away that I visited last week, mainly to check out camping stuff, which amazingly they do have even at this time of year. I know I'll have other supplies to get too so I'll probably go back up there soon. But the van isn't going anywhere for a while; there's currently 6" of snow on the ground and it's still coming down. So today is for indoor stuff - like cleaning the apartment and some online work.

The battery is installed and, according to the mechanic who did it, charging when the engine is running. (And for another miracle - they didn't charge me.) So I'll be looking for inverters next. But I thought I might as well ask while I'm thinking about it - if I can't find an inverter with a digital readout what kind of device would I need to check the battery? I've heard of multimeters but am not sure what they do, and that's about the extent of my knowledge in that area.

Meg

[markopolo]

A multimeter would give you the info you need but it is not practical because you'd have to take it out every time you use it and then pack it up again. Sound simple but, being off grid, you'll be checking your battery status regularly.



These just give you an estimate of battery status. Many new RV's have something similar. Output is shown as "Poor", "Fair" & "Good". Some also show "Charging". A numeric digital readout is much better. I saw some on eBay starting at $5. You want one that is not on all the time wasting current. A push button or switch to show you the voltage is best then it goes off until you check again.

A little off-topic but do you have a roof vent in your van. If not it is worth considering. With a roof vent, you can have the van windows closed for security but still get some fresh air.
Vent fan link: http://www.classbforum.com/phpBB2/vi...php?f=12&t=809

[MegA]

So, these stay connected to the battery all the time? Or at least the one on the right does? The one on the left looks like it plugs into a 12v outlet so it would work for the vehicle battery (plugged into the cigarette lighter) but I'm not sure how I would connect it to the house battery.

Also, can I connect something like this to the battery when the inverter is connected as well? The inverters I've been looking at all have on/off switches so I don't think they'd need to be disconnected when I wasn't using them. Which brings up my next question: Can I connect the inverter to the battery myself or do I have to get someone to do that, and if so, who? (meaning electrician, RV tech, etc.)

You asked about a vent - the van doesn't have one and I'm not planning on getting one put in. I did think about it but only briefly; there are lots of reasons but the biggest one is, I'm not sure how long I'll have this van and I don't think it would be worth the expense since I'd have to pay someone to do it. I know it would be useful for stealth, which is something I was hoping not to have to deal with but now probably will since I don't think I'll be leaving Denver right away. And of course it could provide ventilation if I have a gas appliance running. But I'll just have to find some way to work with what I have.

Meg

[markopolo]

So, these stay connected to the battery all the time? Or at least the one on the right does?
- - - Both could stay connected because they both have a switch to turn them on.

The one on the left looks like it plugs into a 12v outlet so it would work for the vehicle battery (plugged into the cigarette lighter) but I'm not sure how I would connect it to the house battery.
- - - Add a 12v outlet, or some inverters come with a 12v outlet.

Also, can I connect something like this to the battery when the inverter is connected as well?
- - - Yes

The inverters I've been looking at all have on/off switches so I don't think they'd need to be disconnected when I wasn't using them.
- - - That is correct.

Can I connect the inverter to the battery myself or do I have to get someone to do that, and if so, who? (meaning electrician, RV tech, etc.)
- - - Your inverter will come with instructions. Connecting the cables is easy enough but you should install a fuse and fuse holder (probably 150amp fuse for 1200 watt inverter) and the cables will need to be routed so you might have to drill holes. Instead of the cables coming up through the battery box cover maybe it would be better if they came through the side of the box and them up through the floor where you want the inverter mounted. My guess is that your battery is wet cell, not AGM, so you will need to check the water level in the battery every month or so (if it is not a maintenance free type battery). You need to make that easy to do and keep the area accessible. Cables will also need to be protected from chafing and holes in the floor would need to caulked.

Get a quote for someone to do all of the above. It sounds like a lot but really it is not for anyone who does this type of thing regularly.

[MegA]

Originally Posted by markopolo

Add a 12v outlet, or some inverters come with a 12v outlet.

How would I do that? I think it was mentioned briefly before and it sounded like a good idea to me, if I could get some 12v appliances. But I think someone said I would need something like a distributor panel, maybe? (So far I haven't found any inverters that have those outlets, even at the higher ends.)

Originally Posted by markopolo

Get a quote for someone to do all of the above. It sounds like a lot but really it is not for anyone who does this type of thing regularly.

Who would that be? I really have no idea who to call about it. Would it be an electrician, an RV tech, or someone else? I could probably call one of the local RV places but I'm pretty sure I couldn't afford their rates. I don't think this is something my auto mechanic can handle. (I suppose I could put an ad on Craigslist; I'm just not sure whether I'd find anyone who knew what they were doing.)

I'm sorry to sound so clueless but I've never had to deal with anything electrical before.

Meg