I have heard many people comment about how important it is to maintain the water level in your batteries and keep your batteries charged.
This may sound like a stupid question, but if you do not keep your Airstream at home, what is the best way to keep your batteries charged?
I assume that you could always take a generator to the place where your Airstream is sitting, but how long do you have to let it run while attached to the batteries?
Is a Solar panel a viable option? What else can be done to maintain the batteries if you are not out on the road with your trailer for a month or two?
I did some study on this topic last year when I found my battery dead on my Safari after 60 days of unuse. What I found was quite revealing. With the master disconnect switch on, and all appliances off I found a draw of .10 of amp.
Considering my battery is an 105 amp hour unit, I could understand why it had insufficent power to run the power jack after 60 days.
Turning the master disconnect off, with the only draw being the propane detector, the draw is .09 of an amp. A figure more more tolerable. When the trailer goes into long term storage in the winter, I pull the battery and take it home.
Thanks for your response. It certainly seems from the thread that you listed in the e-mail, that if I am not going to be using my trailer over 30 days, it would be best to attach some sort of Solar device to maintain the batteries.
Since your original thread, what have you done? Have you tried the Solargizer or Battery Minder?
I went to the Pulse Tech web site to get some more information about the Solarizer Solar Charger. If anyone is curious, Pule Tech is the manufacturer of the Solarizer Solar Charger.
From what I see, I can either go with the 5-watt 1/2 Amp model or the 10-watt 1 Amp model. The one thing that the site does say is that these units hook up to 1 12-volt battery or up to 4 four batteries in parallel.
I guess my first question would be, are the Airstream batteries hooked up in parallel? Do you think the 5-watt model is ample to simply keep my batteries charged when I am away from my unit for an extended period of time?
Someone posted this a little bit ago. These seem awfully handy......plus the CCD 25' and the 25' Safari I believe have 2- 12v power plugs inside (cig lighter like connections).
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Computers manufactured by companies such as IBM, Compaq and millions of others are by far the most popular with about 70 million machines in use worldwide. Macintosh fans note that cockroaches are far more numerous than humans and that numbers alone do not denote a higher life form. -NY Times 1991
Originally posted by joshua32064 Jack,
Since your original thread, what have you done? Have you tried the Solargizer or Battery Minder?
I did neither. I just make it a policy turn off the master disconnect switch when I store the trailer between trips. At this point I've been out every 30-45 days since April so the battery still has ample charge to operate the power jack to allow me to get the trailer in the the home driveway.
Once I go into my 6 month winter storage, I remove the battery and bring it home.
I think the real education for me was the amp draw when the the disconnect switch is left in the on position.
Jack
__________________
Jack Canavera
STL Mo. AIR #56
'04 Classic 30' S.O.
'03 GMC Savana 2500
Batteries 101
Let's start at the beginning...
Everybody seems to think that a battery is a battery is a battery.
In reality, batteries are manufactured for 3 types of application:
1) Automotive SLI (Starting, lighting & Ignition).
2) Motive Power - forklift trucks, golf carts, etc.
3) Network Power - standby systems, backup power, etc.
The difference in these applications is like day and night - you have to use the correct battery type for the required application. If you don't, then you won't get the performance from the battery and will be frustrated and/or disappointed.
This is what the applications are designed for:
1) Automotive - Lead Calcium alloy which gives a high current for a short amount of time allowing you to start your engine and run auxiliary loads for a short time. This is not a deep-discharge battery and will not survive too many of these.
2) Motive Power - Lead Antimony alloy which can be repeatedly discharged to 80% of its rated capacity and will give you a good life cycle in this application. In industrial use, this type of battery is designed to give 80% of its rated capacity every day and a life of about 5 years.
3) Network Power - Pure lead or various alloy mixtures which are designed to be float-charged to keep them at full capacity in anticipation of power failures. This type of battery is not designed for deep-discharge cycles and has an expected life of 10-20 years.
There are slight variables to the above 3 applications, but generally, this is what they are designed for.
My general impression is that people are using type 1 - Automotive batteries and expecting them to perform like type 2 - Motive Power batteries in their Airstreams.
That is why I have a problem with battery information websites, such as Phred's - they are too generalized and not focused enough on the application. I am not picking on Phred here - his site is quite good compared to the plethora of other similar sites out there!
Let's take an example such as jcanavera's obsevation:
His battery was unable to allow him to use his power jack after 60 days. I don't know what type of batteries are in this particular application, but assume (dangerous, I know) that they are automotive type. If they were Motive Power batteries, then they still would have been over discharged after 60 days because of the 0.10 amp parasitic load on the battery. The batteries were stated to have a capacity of 105 AH. Using the 80% rule, this gives an available capacity of 84 AH. The parasitic loads give a daily draw of 2.4 amps, so the battery can only provide this for 35 days before the battery is fully discharged to 80% of capacity. Any further load after this time will deeply discharge the battery. An important point here - over discharging a battery at a very low current is much more damaging than over discharging a battery at a high current! If, as I suspect, this was actually an Automotive battery, then it would have been toast much sooner!
Here's a tip when buying a battery - look for the capacity to be stated in AH (Ampere Hours) at the 6-hour rate (C6). This usually indicates that it is designed for cycling duty as per type 2 - Motive Power. Also ask for the cycle life at the 6-hour rate and expect this to be at least 300 duty cycles. Type 1 - Automotive batteries are usually rated at the 20-hour rate (C20) or only show CCA.
Hope that somebody finds this useful.
Cheers,
Dave Harris
__________________
'If you always do, what you've always done.'
'You'll always get, what you've always got!'
http://www.dpharris.com
Ok....so what is the proper way to do this to not blow the radio fuse...I keep blowing my fuse if I am plugged into shore power, but it is all ok if I am boondocking.
Joshua,
I've had the Pulse Tech Solargizer 5 watt model for over 2 years. I've left my trailer for over a month at the hunting site and no electricity. The batteries are used from Friday noon through Sunday noon and then charge with no use until the next Friday. The 5 watt seems to have them topped off when I return on Friday. It is hooked up to one of my 105 amp hr. Delco Voyager batteries but the other is charged at the same time due to the way they are wired. The 5 watt should keep it charged but if in doubt go with the 10 watt if you have any parasitic appliances. Oh heck, just unplug them. I've been impressed with the Pulse Tech product. Also check www.batterymart.com for the BatteryMinder solar charger maintainer.
__________________ Craig
AIR #0078
'01 2500hd ext. cab, 8.1 litre gas, 5 sp. Allison auto
3.73 rear end
Mag-Hytec rear diff cover
Amsoil Dual by-pass oil filtration system
Amsoil synthetics all around
265 watt AM Solar, Inc. system
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