Home audio/entertainment system off deep cycles?

[yattmaster]

First time posting on this forum so bear with me. Some friends and I had a brilliant teenage idea to buy a school bus and make it an RV/party bus. It's a 2004 SF-65 Freightliner, 28ft, CAT 3126 engine(inline 6).
One of my goals and key features of the rig is going to be a full audio system. Including a: home audio receiver(unknown wattage), 4-5 speakers(~10-100W per speaker), LED TV(~80W), Xbox 360(~270W).
Pretty sure I have a pretty solid plan I just want to confirm or get suggestions before blowing $300+ on electronics. Everything I'm doing is trying to be as cost effective as possible.
My plan so far: 2 deep cycle batteries(what are good ones for under $100, golf cart type preferred) that charge from the alternator with a 10AWG wire running from the starter batteries to the deep cycles with a cut off switch for when starting the engine or when it's turned off so I don't drain the starter batteries. Using a cut off instead of automatic isolator to save money.
Then from the deep cycle batteries I will run various 12v systems like lights and phone chargers and things. Also from the deep cycles I will have an inverter(which brand, wattage, pure sine wave or not?) which will power the receiver which will lead to everything else, and then maybe one or two other things occaisonally. Most power will be for that though. We don't need any other appliances RVs have.
Since this is going for the cheap I will only be using one component at a time on the inverter so I can get a smaller one, there are so many on the market for all sorts of prices and I have no experience, I just want one I can use occasionally that won't blow up on me for under $100 if possible. And if I was just using the deep cycles without the engine running how long would this last with moderately priced batteries?
I calculated I will need around 500W to run everything on the receiver the TV, Xbox and speakers(never at max volume if using the TV). But I think it would be best to go at least 7-800W just to be safe, also wondering if i need a pure sine wave or a normal inverter because of the audio receiver and it's potentially sensitive nature.
Another question I have is if my alternator will keep up with all this. From my research I've found that most bus alternators run about 150 amps minimum, that translates to 1800W at 12v which should be more than enough but I don't know how much the bus uses while running.
My main concerns are that I can get something reliable that won't burn up my receiver, and that we won't be 50 miles from the nearest town and find the starter batteries are dead in the morning. What do you think?? Sorry for my terrible writing and maybe dumb questions.

[westend]

Good suggestions by all.
I run 120V entertainment devices with my 12V system, also a small dorm fridge. I have a vintage NAD receiver and two sets of small speakers in boxes, and a 32" LCD LED screen.
My gear is: 300 AH of battery capacity, a pair of GC2 Sam's club 6V's in one bank and a separate bank of 3 AGM telecom batteries totalling about 100AH. I use a Xantrex Prowatt 1000W pure sine inverter. Charging this is a 235W solar panel, an included DC converter, and whatever my towing unit will deliver. I also have a generator but for weekend trips, it stays at home. Everything is connected with 4 AWG, minimum. The connection between the 6V bank and the distribution panel is 1/0 welding cable, the run is 6'.

If you are going to rely on the 12V system to deliver inverted 120V power, you need to do the proper engineering to make it happen with an adequate battery capacity and the ability to recharge before draining batteries to a low level. I'd estimate that using just two 6v batteries over a weekend of audio devices, lights, and possibly other 120V devices will drain the 6V's below 50% SOC. That is the preferred level of discharge not to exceed. A solution would be to add battery capacity or engineer charging into the usage. Solar is a great solution as it uses no energy that costs $$. Starting the bus occasionally is another solution and removes the capital cost of solar but uses fuel. You have decisions to make about the system and a good first step is to break out a pencil and calculator to assess exactly what total power use will be used in a typical day of bus use.

Here is one calculator: PV calculator

[kellertx5er]

"The thinner wire is definitely one of my concerns, it's gotta run from the left side of the bus underneath the body all the way up to floor level on the right side underneath a cabinet, which is at least 9 or 10 feet once all said and done. It doesn't have to charge terribly fast though."

The wire size does not control the rate at which the battery is charged. The state of the battery and the regulator in the alternator determine the charge current. If it decides that the battery needs 60 amps for example, it's gonna try to supply it no matter the wire size. In that case, anything less than #6 will just melt down.

This is just an example, but you get the point. Put in the biggest wire you can. Some things you just can't go cheap with.

[allen8106]

My suggestion: Go with a Magnum MMS1012 inverter and 4 Crown 260 ah 6 volt batteries. Ths will likey cost you more than you are planning but you won't be sorry.

[wa8yxm]

Your plan sounds a lot like my "House" (Class A RV) in that I have a very nice Pioneer Home theater sitting nest to my Main TV next to my Video Electronics Cabinet (Digital OTA TV convewrter, Vintage NTSC only DVR (hence the converter) Sat Receiver (Optional currently elsewhere.. i go to put one in there again some day cause I want to watch one FREE TO AIR Sat channel... The FTA receiver can do that.. It can't show me CSI but it can NASA).

InverterL TRUE SINE WAVE. IN days of old when I was bold I visited the Xantrex web sitek since mine is a Xantrex no longer produced product (hence I can not recommend it) Xantrex used to have a document on their MSW inverter sites "Thingns that might not work as well on MSW inverters"
Sat Receivers
Audio Receivers
Televisons
Any device with electronic components, including Clocks, Coffee pots with timers, Electric Blankets, Night lights.
and even nearby Battery operated radios (IE a pocket radio)

The list was ever growing and now has dissappeared.

Here is the list for TSW inverters

Any device or combination of devices needing more than (Inverter rating) Watts.

For example for my Prosine 2.0 (2,000watts) that's 2,000 watts.

Brands:
In another thread on another forum this question was recently ask. And as it turn out my "Generic" answer is standing up well.

With low end MSW inverters.. Some are indeed ****.

But with high power (1000 watts or more) True sine in-line inverters like my 2000 watt Prosine, which as I said is no longer in production,, Most all of them are very good, Well built and I'd have no problem recommending any of them.

Things to look for:
Load sense: This is a system that looks to see if anything plugged in (120 volt side) wants power. if not the inverter goes into a Standby mode. I do not use this feature but this is because say a 75 Watt Light plugged in to an inverter set to sense 100 watts.. Will BLINK Yes I can adjust the load sense. But I'd have to go mighty low to have the Microwave clock be load enough and. Well. I don't want it blinking at me. Thus I leave the load sense off so the unit operats as a UPS and keeps power to the Clocks all the time.

Programmable Battery pramaters:
On my prosine I can set the charge profile. Bulk, absorption, float and equalize voltages and current limits. Time limits if desired and more.
This is a good thing because if I change battery types. I can re-program for the new batteries (Tried that once, Had the Inverter on a pair of Group 31 AGM's. They were the newest batteries in the RV, the Prosine was set to AGM, and ... they were the first to die, Lasted only about half as long as the Flooded wet cells which were eating off a Progressive Dynamicsa 9180 with wizard (Both the Prosine nad the Wizard get top ratings from me) Went back to all Wet cells.. Much happier now. I see your plan is Flooded wet cells. very good.

I would also look for a Remote Control panel

Though I did state that both the charger in the Prosine and my Progressive Dynamics Wizard converter are top rated (for different reasons) I like the PD IntellaPower's program slightly better (we are talking like 99%/100% here They are both top end 3-stage PLUS one feature. it's the PLUS I like better and this is actually a personal preference, not a technical one.

So I simply turn off the charger in the Prosine from the Remote... UNLESS
1: Since I more than doubled my battery bank (From 22o hamp hour to over 500) when running on Generator I can use the extra amps so I switch on the Prosine and

2: My PD is a "plug in" model in an outside compartment.. From time to time I've accidently pulled the plug.. Well,,, This is an issue because it don't work that way :).. I often get up around 3-4 Am to visit the "inner office" (the one with the plumbing) and to check into a Radio Net.. Notice the battery voltage indicator is reading a tad low and think "Oh ****!. The Converter is off line again.. now I have two choices, Get Dressed, Grab my TAC-1200 flashlight, go out and plug it back in.. Or Flip the switch on the remote panel INSIDE.. Guess which I choose :). Radio is happy, I'm happy and tomorrow. I don't need to run down the battery on the TAC-1200 super flashlight. 🙂

[DrewE]

Forget that battery; it will not be sufficient for your proposed use. It's tiny (35 Ah) and rather expensive for what it is.

At a minimum, I would suggest two 6V GC2 golf cart batteries wired in series; they can be had from Costco or Sam's Club for somewhat less than $100 apiece. This will give you a 12V battery of about 220 Ah capacity, or over six times the power, and they're designed for much more the sort of usage you'll be having rather than the multipurpose battery you linked. (It's worthwhile to ask around at golf cart dealers in the area to see what they're charging for batteries, too; sometimes they'll have deals that are equal to or better than Costco/Sam's Club, and sometimes they won't come close.)

[2oldman]

The Walmart battery is only 35ah. Even 4 of those won't get you very far. Your inverter choice is bottom of the line quality. But, I guess you have a budget to consider.

[yattmaster]

hedge wrote:
I don't understand why you want to build it with home stuff, car audio stuff would be easier and it's already made to run off of 12v?

I already have all the components I need for it lying around. I figured I might as well use an inverter with my electrical setup rather than get all the new things I would need for a car audio system. They also don't get as loud and I don't think you can hook up a TV or anything to it.

[hedge]

I don't understand why you want to build it with home stuff, car audio stuff would be easier and it's already made to run off of 12v?

[yattmaster]

DrewE wrote:
I think you're basically on the right track. It sounds like it could be a very fun project, though undoubtedly a good bit of work.

The entertainment systems are generally not going to be consuming their maximum rated power; this is particularly true for the receiver's audio amplifier, assuming it's not a very high end class A amplifier.

I would suggest a pure sine wave inverter for this use, not so much out of concern for the safety of the equipment as for the liklihood of picking up spurrious noise from many MSW inverters that put out a lot of electrical noise. A 1000W unit would be plenty; a 500W or 600W one would probably be sufficient; however, in my opinion the difference in price is small enough that the larger size seems more sensible.

Guessing at a system average power usage of about 200W, a pair of golf cart batteries would last about five hours before getting down to 50 percent charge. Lead acid batteries don't take well to being deeply discharged, and especially to being left in a discharged state; I wouldn't suggest going too much below 50 percent. Lighting, if any, and any fridges etc. would of course add to the power consumption.

For connecting to the vehicle electrical system, you do need an isolator of some sort, which you've basically described. Having a continuous duty contactor (or heavy-duty relay, which is basically the same thing under a different name) to connect the battery banks together when the engine running is pretty straightforward and can be done reliably. Often this is controlled by a switched circuit on the vehicle side, so it's engaged when the key is in the run position. Occasionally there are somewhat more sophisticated schemes, maybe with voltage sensing or time delays or such.

You would be very well served to have heavier wiring between the batteries than a 10 gauge wire. My class C motorhome has, as best as I can make out, 2 gauge wiring, fused at 175A at either end. Charge currents for golf cart batteries can easily be over 50A, and having a thin wire (with its resistance and voltage drop) will unnecessarily slow down charging from the vehicle electrical system.

It would not be a bad idea to also have some sort of an AC powered charger ("converter" in RV parlance). Depending on your usage, it could be a fairly small smart charger, mainly to maintain the battery's state of charge, or it could be a somewhat more powerful one that can recharge it in a reasonably short length of time. Progressive Dynamics makes some excellent ones for the latter use.

I do hope you've researched registration and driver's licensing laws for your proposed uses. In general this would not be able to be registered as an RV, and you'd probably need to have a class B CDL, quite possibly with a passenger endorsement (if it seats more than 15 including the driver), to legally drive it. An RV for personal use does not have these requirements, but does have certain minimal equipment requirements that may vary a little from state to state but typically include having at least some subset of permanently installed sanitation systems (a toilet), cooking systems, a permanent electrical system, sleeping bunks, etc.

Thanks for the quick reply. The thinner wire is definitely one of my concerns, it's gotta run from the left side of the bus underneath the body all the way up to floor level on the right side underneath a cabinent, which is at least 9 or 10 feet once all said and done. It doesn't have to charge terribly fast though.
We will charge the batteries up fully from a car battery charger I have already before each trip and we will drive 2-5 hours per trip then camp only 2-3 days typically, and only hang out inside at night, probably driving in between somewhat, I'm also considering a solar panel but that is another $150. Hardly any other 12v systems will be used though, no water pump, no fridge, ect.

As far as the inverter would this work alright for how low the price is? https://www.amazon.com/gp/aw/d/B01ALHANG2?psc=1

And the batteries: https://www.walmart.com/ip/12V-35AH-Light-Trolling-Motor-Sealed-Battery-Sevylor-Minn-Kota-Golf-Cart-AGM/149406140?wmlspartner=wlpa&selectedSellerId=1082&adid=22222222228049616421&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=m&wl3=145272666681&wl4=pla-262099847748&wl5=9029683&wl6=&wl7=&wl8=&wl9=pla&wl10=112561763&wl11=online&wl12=149406140&wl13=&veh=sem

As far as lisencing I'm pretty sure I have that figured out. The previous owners already took out the seats and put in a new floor and some cabinents, they had it as an RV with AIS, and I'm going to do quite a bit more, kind of like the same systems a tent trailer has. Gravity fed sink and a portable toilet, no tank system is my plan, already have a stove and all that so I've just about covered all my bases.

[pianotuna]

More amp-hours of battery bank.

[tplife]

Keep your expectations for quality very low. A decent subwoofer runs 600W with 2Kw peaks, and that's just the sub. A good 7-channel amp is 100W/channel continuous to be able to reproduce clear notes. If you don't expect much, you'll be pleased with the outcome.

[MEXICOWANDERER]

http://www.partsexpress.com

Somewhere in there are midrange horns for like four dollars. They sound great and they do not need any type of crossover network.

Choose the highest wattage LEPAI receiver amplifier they offer. It has all the connection points.

For Bass, I would go with a ten inch powered under-seat woofer. But understand, woofers needs LOTS OF AMPS or they sound piffy like laptop speakers. Plan-on one group 31 AGM battery within a 5 foot distance and six AWG charging leads. I is not hard to set up a dedicated charging system.

With such a system as I have described, the sound level would be of immense potential. Spot-weld cracking bass and mid-range guitar and keyboard volume realism that could slam both eardrums together in the middle.

The surprise comes when his system is compared to incredibly complicated and expensive auto sound systems and blasts the competition clear out of the auditorium. Like with many electronics, the idiots that think they know what they're doing reproducing music on speakers haven't a clue. I spent years developing incredibly high amperage Nippondenso, Hitachi, and Mistubishi alternators, for "Northwest Regulator" and the thousands of dollars those kids wasted on car stereos produced sound quality worthy of a 1957 Wurlitzer jukebox. It was pathetic.

I modified many home speaker systems with those Parts Express Magnavox Astro Sonic horns. My favorite was coupling the horns to Acoustic Research AR 4, speakers. Klipshorn Folded Corner Horn speakers were good, as were Altec Lansing Voice of The Theater speakers. But all are gigantic enclosures. What I wrote above is quite small.

[DrewE]

I think you're basically on the right track. It sounds like it could be a very fun project, though undoubtedly a good bit of work.

The entertainment systems are generally not going to be consuming their maximum rated power; this is particularly true for the receiver's audio amplifier, assuming it's not a very high end class A amplifier.

I would suggest a pure sine wave inverter for this use, not so much out of concern for the safety of the equipment as for the liklihood of picking up spurrious noise from many MSW inverters that put out a lot of electrical noise. A 1000W unit would be plenty; a 500W or 600W one would probably be sufficient; however, in my opinion the difference in price is small enough that the larger size seems more sensible.

Guessing at a system average power usage of about 200W, a pair of golf cart batteries would last about five hours before getting down to 50 percent charge. Lead acid batteries don't take well to being deeply discharged, and especially to being left in a discharged state; I wouldn't suggest going too much below 50 percent. Lighting, if any, and any fridges etc. would of course add to the power consumption.

For connecting to the vehicle electrical system, you do need an isolator of some sort, which you've basically described. Having a continuous duty contactor (or heavy-duty relay, which is basically the same thing under a different name) to connect the battery banks together when the engine running is pretty straightforward and can be done reliably. Often this is controlled by a switched circuit on the vehicle side, so it's engaged when the key is in the run position. Occasionally there are somewhat more sophisticated schemes, maybe with voltage sensing or time delays or such.

You would be very well served to have heavier wiring between the batteries than a 10 gauge wire. My class C motorhome has, as best as I can make out, 2 gauge wiring, fused at 175A at either end. Charge currents for golf cart batteries can easily be over 50A, and having a thin wire (with its resistance and voltage drop) will unnecessarily slow down charging from the vehicle electrical system.

It would not be a bad idea to also have some sort of an AC powered charger ("converter" in RV parlance). Depending on your usage, it could be a fairly small smart charger, mainly to maintain the battery's state of charge, or it could be a somewhat more powerful one that can recharge it in a reasonably short length of time. Progressive Dynamics makes some excellent ones for the latter use.

I do hope you've researched registration and driver's licensing laws for your proposed uses. In general this would not be able to be registered as an RV, and you'd probably need to have a class B CDL, quite possibly with a passenger endorsement (if it seats more than 15 including the driver), to legally drive it. An RV for personal use does not have these requirements, but does have certain minimal equipment requirements that may vary a little from state to state but typically include having at least some subset of permanently installed sanitation systems (a toilet), cooking systems, a permanent electrical system, sleeping bunks, etc.