| Author |
Message |
Thomas Griffin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 26, 2005 - 10:03 pm: | |
Just purchased a 4104. I want to fix this bus right, so, I've hulled it out. I'm replacing the insulation in the celling, sides, decoupling the walls, floor and installing a floating floor. Now for the question....
I'm setting up a battery bank. I'm going to use it to run a lot of things such as the entertainment system(TV, STEREO, SAT, DVD..) I'll get a large inverter(s)(might set up 2 systems) to feed these items (include a roof mount). By my calculations I should have about 4 hours of use in the bank. I will then connect an inverter to the BUS system. It will be a smaller one. The only thing it will have running on it will be a charger that is connected to the battery bank. Both inverters will have a remote to them. My question is this:
1- If I leave the charger on at all times, it should detect if the battery drops below a certain level and begin to charge. Will this maintain the battery Banks? Will this "murder" the battery bank?
Thanks
THomas |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 12:01 am: | |
Tom,
You're using deep cycle batteries, "real" deep cycles that is? Lead Acid, AGM or Gel's?
Each require different care and feeding and can be efficiently discharged to various levels, but the most efficient target to generally aim at is run them down to 50% and charge them back up properly and fully, using a "smart" 3 stage charger.
Anything else and your normally expensive power, via batts, goes way up. You can run them anyway you want, that's your privilege. Some will say, however, if money doesn't mean that much to you, you probably could afford a used Marathon.
2 real good resources on "off grid" living are Amplepower.com and Home Power Magazine. |
THomas Griffin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 12:25 am: | |
WIll I be able to recharge while using the bank, and how long will it take to recharge?
I have yet to purchase the batteries, I have researched and found that the 8D's are what's needed???? |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 1:47 am: | |
Thomas, I read and reread your post, and I don't understand what you are proposing.
Every inverter, if it has a charger, will connect to both batteries and the AC power panel. But, I can't figure out what you intend to connect this smaller inverter to.
To better understand what you are dealing with, you are simply shuffling power around, while changing its characteristics. The inverter will probably cost you 10% or more of the power that it handles.
The length of time for anything to happen will depend on the total amount of power (say in kwh) that needs to be shuffled from one place to another, the efficiency of the transfer and the rate of the transfer.
You have not mentioned any of these things, so we can't begin to guess the answer to your questions.
Some basics: if you use golf cart FLA batteries, they will have a total capacity of around 1 1/3 kwh. In normal use, you will only want to discharge these down to about 5/8 kwh and then recharge them to about 1 1/8kwh.
Then, for several cycles, you will be able to use about 1/2 kwh between charges. After several cycles, a full recharge would likely be a good idea. These recharges will require something like 1/3 more power than you took out of them.
If you want to have 3 kwh of power to use between recharges, you will need about 6 golf cart batteries. That would work pretty well with a 12 volt 2000VA inverter with a 100 amp charger, because the charge would only be about 1/6 of the capacity.
This would give you a good life in the batteries. Recharge time would run a little over three hours. Does this sound like what you have in mind?
How long will you be able to camp on 3 kwh? You'll need to add up your loads and your run time for each of them in order to know.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 1:51 am: | |
Whatever you do, don't put sodium cloride on these power cells.
You'll get arrested. "Salt'n'battery". You just can't do that. |
Brian Brown (Fishbowlbrian)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 2:39 am: | |
I'm reading his post and confused, as well. I really think he's proposing the typical house side and coach side. BUT, if I'm reading correctly, he's wanting the coach side to charge back up the house side via the charger through the "smaller" inverter that's on the coach side.
If so: Thomas, you'd not need the smaller inverter at all on your coach side, but use the charger attached to an AC source like the genset or the power pole. Your bus alternator (sometimes called generator... to add to the confusion) can charge either house or coach side, when the engine is running, of course, though not as effectively as a true three-stage charger.
Thomas, I'd advise you to read David Smead's books about building and living on 12v power. They'll help you sort out all of these electrical issues.
FBB |
Brian (Bigbusguy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 2:49 am: | |
I think you was asking if you can put a smaller one on the start batts. Yes I dont see why not.
I have a small 3 stage inverter charger on my start batts that will also work as a inverter if I need it.
I leave it on most of the time in winter.
Most newer chargers are smart now and will not hurt any thing leaving them on 24/7 they go to a float voltage until the batts need charging.
Brian 4905 Klamath Falls Oregon |
Thomas Griffin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 10:16 am: | |
Guys I am so sorry for all of the confussion. I'll try it again....
Yes, I am proposing to recharge the battery bank while traveling. Explaining my use would help out too.
I will be traveling most of the time. When I am stopped, it will be plugged into utility power. The most time that I will be stopped will be for 5 to 8 hours without a utility to connect to. I will not be parked for days at a time.
Instead of running the genset while traveling, I want to use a battery bank with most systems. I'll be purchasing a 5000 watt inverter, maybe 2. I'll be on the bus traveling for 8 hours using the battery bank, but I know it will not last long, so I'm trying to charge the bank via the second smaller inverter with a great battery charger.
You may know of a better way with all of the products out there. I'm all ears believe me...
AND... THANKS FOR THE REPLIES... |
Doug Dickinson (Dougd470)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 11:44 am: | |
OK, here is just one way. There are lots to consider.
If you get compatible batteries for the house v coach systems (like golf cart batts and standard vehicle batteries, you can just place a BIG switch in between the batts that will parallel the coach and house batts when you are on the road. The coach alternator (generator) will charge both in parallel while on the road. If you have a 12 volt coach, you will have to use a 12 volt house string. 24V and 24V would also be necessary if that's the case.
In operation, the coach batteries are tied in parallel to the house batteries with the inverter drawing power off the parallel arrangement fed by the coach alternator while the engine is running. When the coach is turned off, the coach batteries are disconnected (automatic would be a good idea with a manual over-ride for jump starts) and the house batts carry the inverter load for however long the batt stack is rated for.
The advantage of this arrangement is that you have a backup to jump-start the coach if need be if your coach batts are dead for some reason. If you get a good inverter (and this is important to get a really good one) you will probably have a built-in 3 stage charger to recharge the batts fully when docked at a power pole. These also can function much like a UPS giving uninterupted power - an added bonus with electronic stuff.
One caution, a coach alternator is usually in the vicinity of 4000 to 5000 watts which is a LOT of power. You need to look at how much you are drawing off the stack and make sure you do not draw more than the coach is creating, or you will have dead batteries everywhere. Also, don't forget to figure in the coach loads as well as the house loads to this arrangement.
I suggest you make sure the coach and house batts can be fully separate or you could be lonely in a bad place at a bad time. Built wisely, you could have levels of redundancy that would astound you.
Doug
St Louis MC9 |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 1:27 pm: | |
Gee, this all makes a great case for propane.... |
Jim (Jim_in_california)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 2:51 pm: | |
In the pre-inverter days, it was common to put a big diode in between the coach battery(s) and the house battery(s) so that the house battery could SUCK power out of the running motor but couldn't put electricity back into the "coach side wiring".
You would then have a manual switch connection to basically disable the diode and allow house battery juice to go to the starter if the coach side battery went dead.
Not a bad thing to basically replicate. |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 5:59 pm: | |
Umm... Battery isolater and an override switch.
They sell 'em.
http://www.google.com/search?hl=en&q=Battery+isolater+&btnG=Google+Search |
Jtng
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 6:00 pm: | |
ooops:
http://www.google.com/search?num=30&hl=en&lr=&newwindow=1&safe=off&c2coff=1&q=Battery+isol ator+&btnG=Search |
thomasgriffin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 27, 2005 - 11:14 pm: | |
Thanks everyone for the info...
Hey Doug...
The system that you are describing sounds like what I'm going to need. Could you tell me what components I'll have to have for set-up and wiring of the system?
Thank you |
Doug Dickinson (Dougd470)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 28, 2005 - 10:12 am: | |
There are lots of resources that can guide you better than me. My approach is simple in that you have the house system with the inverter and the coach system. You tie them together with a big relay.
For an invertor, I like the SW4024, which is an incredable device (and costs $$$) but I feel it is worth every buck. There are smaller versions and they come in 12 and 24 volt configs. Lots of folks sell them.
Some folks mentioned a diode, which is good to isolate, but costly in the size we are talking about here, and could get you in trouble with dead coach batteries. I would stick with a total physical disconnect between the systems. My $0.02 worth.
Resources like back woods solar can help with product selection. Do a google search for alternative electric or some such term and you will find several. Perhaps some folks here can contribute sources.
Doug
St Louis MC9 |
Jack Gregg (Jackinkc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 28, 2005 - 3:48 pm: | |
[long post] As I understand the question as posed in the first post:
1. Thomas proposes a COACH CONVERSION system that will consist of 24v batteries and an inverter to power stereo, TV, etc.
2. Thomas proposes no modifications to BUS system (alternator, starting batteries, etc.) except as noted under number four below.
3. Thomas proposes that there be no connections between the coach conversion system and the bus system except as noted is number four following.
4. Thomas proposes that a small inverter be powered by the starting batteries. This inverter will only be used to power a battery charger. The battery charger will only be used to charge the coach conversion batteries.
5. Thomas poses the question: If I leave the charger on at all times, it should detect if the battery drops below a certain level and begin to charge. Will this maintain the battery Banks? Will this "murder" the battery bank?
If I have restated the question right then the answer is: It will work “sort of” as long as the bus is running and charging the starter batteries.
The main problem is that the small inverter hooked onto the starting batteries will drain the starter batteries whenever the bus is not running. The problem could be avoided by only running this small inverter when the motor is running.
Another objection is that Thomas proposes (if I understood) using an inverter to power a battery charger. This induces both in inefficiency of the inverter and the inefficiency of the battery charger.
Much better configurations are available. I like the pathfiner by xanex. The pathfinder is basically a battery isolator that works in both directions. A manual override is available to start the engine off of the coach batteries if necessary.
There is no one best electrical system design. In addition to money and mechanical constraints, system design depends on how the electrical system and coach will be used. Thomas did not mention a generator but if he is thinking about two inverters then a generator must be coming too.
Think about powering the bus in four different situations:
1. Plugged into shore power at home or in a campground - everything will run off the shore power. If you use trace 4024 inverters the shore power can go through the inverter to get to your 110v power distribution panel. Some vendors (including Dick Wright at Wrico International) advise against going through the inverter and will sell you an automatic switch (relay). Whenever you are plugged into shore power you should be charging (or at least monitoring) both battery banks.
2. Boondocking – no shore power, engine not running, auxiliary generator not running. All power comes from the coach batteries, 12v, 24v, or 110vac from the inverter.
3. Auxiliary generator running – you need the auxiliary generator is when you are boondocking. The auxiliary generator can be used to power loads that are too large for the inverter like air conditioners and an electric range. The auxiliary generator is used to recharge the coach batteries. In addition to boondocking, some coach owners use the auxiliary generator to power air conditioners while driving down the road.
4. Driving down the road: the situation is the same as boondocking except that excess 24v power is likely available from the alternator. This may be automatically sent to the coach batteries with a battery isolator or a pathfinder. Properly configured, most blokes will agree that this power can run one roof air conditioner off of an inverter while in route.
Ideally, the bus would automatically adjust or switch between each of the above situations. Theoretically this can all be done with a SW4024 inverter and a pathfinder. However it is not practical to run all loads through the SW4024.
My apologies to regular readers of this board for restating what others have already said before on this board. Dissenting opinions are encouraged and enjoyed. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 29, 2005 - 10:24 pm: | |
Very well written, Jack. Now, the devil is in the details. This is where many people balk.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
Jim-Bob (Pd41044039)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 30, 2005 - 2:42 am: | |
Please note that a 4104 is a 12 volt coach. And it came from the factory with a GENERATOR, which is not at all the same as an alternator. The 4104 was also built as POSITIVE GROUND.
Many of these coaches have been converted to 12 Volt, negative ground. It's not hard to do. Many have also been converted to alternators in various ways, some good, some not so good.
The most trouble free way to power his needs while underway would be if his coach had a modern, 300 amp, oil cooled alternator installed in place of the original generator. It's a bolt on swap. (Wiring & regulator will change.)
Connect the big alternator to the house battery bank & the starting batteies with a diode type splitter that will not allow the engine battery to back feed. (It would be better to install a second smaller, belt drive alternator of maybe 100 amps to supply the engine batteries but there is no place to drive it from unless his bus will not have hydraulic power steering.)
Install an on/off battery switch to connect the banks in case the engine batts ever went dead. Label the switch to be left OFF except for emergency. Keep the two systems separate.
Inverter/s will need to be 12 volt type, not 24.
Jim-Bob |
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