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uwe · 07-15-2002, 10:17 AM

I have a few concerns about the battery in our 1971 Tradewind:
There is a Battery door which goes to under the rear bed area, and above it there is a small vent with a vent hose attached to it. That's it. No Battery box or containment or hold down of any kind.
I would like to know what all is missing, or if anyone has modified this setup to hold 2 Batteries.
I have looked at marine type battery boxes, but they are not sealed, just basically a battery container with a lid. What about fumes and /or acid etc.??
I was thinking of perhaps relocating the batteries to the area behind the propane bottles, for safety and convenience.
I am open to suggestions and any information is appreciated.
Uwe

71tradewind · 07-16-2002, 03:27 PM

Hi ! there is infact a hold down for the battery mine was a metal plate that was screwed to the floor then a clamp that went around the battery. I removed mine and put a more up to date marine type battery box made of plastic. You can find them at sears,wallmart,ect. These boxes will contain the battery in case of a spill. If you have any more questions , i will be happy to answer them to the best of my ability. Tom

71tradewind · 07-16-2002, 03:37 PM

Oh almost forgot as far as fumes go , you could seal the vents the drill a hole and insert the tube in it. I also had the same concerns but then thought of how many airstreams have been made this way with only a tube placed near the top of the battery ,and have never heard of it being a problem . I dont think i would relocate the battery to the front for 2 reasons the 1st being the most important, the long run of wire from the univolt will more than likely have a large voltage drop at that distance requiring you to run rather large cables Ie 4 quage or larger. 2nd the extra wieght on the tounge esp 2 batteries remmeber how far back your axles are plus the already heavy tounge weight of a tradewind. Hope this helps ! Tom

uwe · 07-16-2002, 04:10 PM

Thanks again, Tom. This does help. i am new to this, for the most part.
I will search for decent battery boxes and then make an aluminum rail that holds them down with long allthread, or the like of it. I guess i could make a connection manifold between the 2 battery boxes and connect it to the outside vent, just in case. It's easy to do and can't hurt, right?
So Airstream did not really have a slider or other mechanism for the battery behind the door, i guess? Just a plate and holddown.......interesting.
I agree on the tongue weight - not a good idea to add 2 heavy batteries to it.
Thanks,
Uwe

davidz71 · 07-16-2002, 05:08 PM

Check Summitt Racing as a source on the web for various types of battery boxes.

FrankR · 07-16-2002, 05:32 PM

Oh boy, I gotta disagree....
Batteries out gas with hi activity.
battery vapor or gas rises
batteries enclosed need not be pressure sealed
marine batteries are very carefully placed and use a plastic battery box
Airstream trailers rarely use greater than 30 amps to do any task, so a 10 gage stranded wire will work great for any battery placement.
Batteries on the front of a trailer get more service as out of sight ..out of mind is common...
The new trend for battery placement is on the trailer tongue

I'll add more later.......

71tradewind · 07-17-2002, 04:53 AM

Frank the things you point out are true except you must take into account for voltage drop as well ,plus if the unit has the original univolt it may not be as effecient as it once was,so the battery may not get the necessary charge to maintain a proper charge,then comes the problem of running on to low of voltage! currant increases as voltage drops .Plus adding any wiring to an A/S is no small task esp. to do right ie. "safe".The current battery location is directly behind the axles which from a load stand point makes it near ideal"over the axles" is best plus the fact that the tradewind axles are set towards the back of the unit ,adding any weight up front multiplies it quit a bit, it is true that the trend is moving them forward but the axles are also towards the center of the units , NOT set back nearly as far as our 71 tradewinds are. As far as gasses go yes it is safer to vent them ! but it does not seem to be a problem as they were oringinaly was more or less just vented to atmosphere with a small piece of tubing laying near or acroos the top of the battery. My post are not done with out thought put into them and i do not want to overwhelm people with too much info ,In jest all i was saying is its better to leave them where they are put them in a better box and if you like vent them better.With all do respect please dont make this and i know more than you do thing, every one has valuble info including you !

Pahaska · 07-17-2002, 05:37 AM

I have to agree with FrankR on the wiring question.

#10 should be plenty for current from the battery unless you have unusually heavy requirements. There is ordinarily nothing in any coach that would be sensitive to the very minor voltage drop caused by 30 or so amps through #10.

When on shore power, charging current from the UniVolt to the battery is only a few amps, therefore, the voltage drop will be even more negligable.

I just looked at the wiring diagram for my International and the battery feed to the panel is 159" of #12 wire. Both hot and ground are #12. The only #8 in the entire trailer is a chassis ground that runs from the tongue area to the center of the back of the trailer and connects to nothing else.

71tradewind · 07-17-2002, 07:10 AM

I agree John But were talking about moving the batteries apporx. 20 feet of wire or more away from the univolt, wire lenght exceeds actual distance because of turns , having to go around things ect. My unit has 7 light fixtures 4 bulbs each ,water pump, furnace, range fan,bathroom fan, 2 reading lamps,docking light,tounge jack,poarch lamp,radio,way more than 30 amps worth if all added up.All these add up if they were turn on at once. You cannot safely wire for "normal use" whats normal for you,Frank, and I may not be normal for others. You have to wire for worst case senerio. The current location of the battery has a 2 foot run of appox 10 gauge .Without moving the univolt also ,I feel its safer to run heaver than lighter wire at that distance . But why move the battery at all is what it still comes down to.Its in a real nice area to begin with ,there is NO advantage to moving it. Tom

FrankR · 07-17-2002, 07:42 AM

Again I must disagree with Tom. My background was mostly as a electrical contractor for 30 + years. I'm very familar with wiring and loads. Line loss does not play any part in relocation of a battery in an Airstream. Any loads are protected by the seperate fuses . Even the battery is fuse protected. It must be your opinion that Airstream and other trailers have a big design flaw by relocation of batteries. You can believe me, when I say my wiring is not the norm. I've made many many changes. It is my belief that Airstream made too many decisions based on a few dollars...... Your arguements are not based on any scientific information only opinions. It is MY OPINION, that the grounds should NOT be fused. I have never witnessed another piece of equiptment where the ground is fused. Others may be different, but the 1979 Airstreams are wired this way. Is there any example or information that I can provide to make you better understand??

Pahaska · 07-17-2002, 07:55 AM

I have almost precisely the same items in my International. You don't have to size the wires for 100% of the load ... it never happens. Maximum draw with absolutely everything on at once in my International would be 88.28 Amps. Airstream applies a formula as follows (from the manual):

1st 20 amps - 100% = 20 amps
2nd 20 amps @ 50% = 10 amps
rest of amps at 25% = 12.07 amp
____________________________
Grand total amps = 42.07
Converter is rated at 45 amps.

Actually, based on wire cross section, 21' of #10 is equal to the 13' of #12 that AS put in my trailer.

uwe · 07-17-2002, 09:58 AM

I find all your replies very interesting. And i thank you all for your involvement. The electrical understandign that I have tells me that you all got very good points in this issue.
I decided not to relocate my battery, because I do want to keep using my trailer this summer, and if I started wiring, then I would be removing 1/2 of the trailer's interior and bellypan from the current battery location on forward.......I like doing things safe and sound.
So, instead I am shopping for Gel Cells. My friend has a garage, he can buy them at wholesale and give me a good price, basically wholesale cost plus tax and a six pack of suds. I am told that the Gel Cells do not fume out, and are impervious to mounting locations etc. Now we got to figure out which ones. I believe I saw a thread already in here. The batteries in question come from Interstate, which i had good luck with in my cars all these years. They have yellow, blue and red tops, i believe.
I will stil put them in battery cases, just to keep things neat. I actually look forwad to cleaning up the rats nest of wiring near my Univolt.( Original)
I am still not sure if the Univolt can charge 2 batteries in parallel.
Uwe

71tradewind · 07-17-2002, 04:41 PM

This is exactly why I dont post more offen ! Sorry UWE .

thenewkid64 · 07-17-2002, 06:42 PM

2 matched batteries wired in parallel should be no problem for the univolt but you may want to carefully look at the charging requirements on the gel cells you are installing. If my memory serves, (I have a bad case of CRS, Can't Remember S**t) gel cells require a higher boost charge to get them fully charged after a long discharge. I think that makes sense. Basically gel cells require a higher voltage to properly condition and charge them than a traditional wet cell. Anyway I would check out the manufacturers spec. on charging before spending dinero in the new batteries. On the other points, outgassing, mounting etc. you are correct. So inside un-vented is fine. Just my $.02 cents worth.

thenewkid64 · 07-18-2002, 05:23 AM

I did not like the fact that my last post was vauge so I did a bit of research and found out that the reccomended charging voltage for a gel cell is usally 14.1 volts. Charging at a higher voltage is bad for the battery. I would check the votage output of your univolt and see if it is at 14.5. If so you may want to see if it can be adjusted to a lower max output. There, now I feel better!

uwe · 07-18-2002, 09:38 AM

Hi Brett,
Thanks for all the research. I'll finish my water heater installationa and then go on to the battery project. It looks like a rats nest where the Univolt resides, and i alrady know it's going to be the proverbial can of worms, like everything else I did so far on this trailer. That's what I get for loving this old trailer. We'll havo to increaso the ratio of camping time/work on it time in favor of the camping time. Maybe by next year.....
This forum has shed quite a bit of light on things.
Uwe

71tradewind · 07-18-2002, 11:07 AM

UWE if you need to know where any of the original wires go or what its supposed to look like , I can send you photos of my univolt and wiring . mine is orginal and in very good shape. Tom

uwe · 07-18-2002, 11:23 AM

Hey TOM, pictures would be great. It really looks suspect down in there. I 'll take some before and after shots, if I can get in there with the camera.
I am measuring 13.06 Volts at the battery terminals, and 13.04 volts at the ceiling fan wiring and at the ceiling lights. 13.04 Volts also at the tongue jack wiring, furthest from the battery and Univolt. My battery is supposed to have a charging voltage of 14.6V. Hmmm.
I am going ot wait a few hours and see if after charging the battery my voltage will increase.Sometimes the voltsge drops a little bit on a partially discharged battery.
Maybe the Univolt has seen better days, or maybe the rats nest is getting in the way of a good charge.
Uwe