Quote:
Originally Posted by fran&frank
One solution is to install a battery disconnect switch at the battery so when it is off there is no parasitic drains on your battery when in storage.
If you make sure your batteries are fully charged and disconnect them they should be OK for months when in storage.
Also just to get terminology straight, a convertor provides 12 volt power to your trailer 12 volt circuits, a charger charges the battery. Airstreams come with a combination converter/charger and some with a separate invertor for AC power. Some people upgrade to a better multistage convertor/charger while others who are doing more substantial electrical upgrades go to an invertor/charger and eliminate the converter component all together --Frank |
Ahhhh Hmmmm... well.... indeed a battery disconnect swtich is nice.. but just make sure everything is OFF... will work too... that being said.. instead of going around and turning everything off the switch takes care of that in one motion... My trailer came with it...
As to bats lasting through storage times... attt wrong answer... sure if you charge them up.. they are going to last longer.. but... through the ages we have found that a fully charged battery will self discharge in about 90 days... most auto manufactures claim that you need to run the vehicle ever two week (14 days) or sedimentation will set in. By this we mean the battery will start to sulfate... and die a death of inability to provide its current capability.
So with Solar and others... you will keep the bat topped off and working while in storage ...most of the time... A lot of the solar controllers have built in functions to keep the battery conditioned... but, your relying on the sun to keep 'em up...
Ahh yes the converter vs battery charger issue... that always seem to come back around... some even call them inverters... but which is right...
Well first off the inverter is the thing that takes the 12 volts and makes it into 120v ac. The battery charger is the thing which only function is to recharge the battery as quickly as it can. They have very little regulation and so after the battery is charged fully... will start to boil them because they contenue to put out voltage that will go above the batterys requirement for MAINTENANCE charge. Thus they will kill a battery if left on as it boils away the plates and liquid inside.. over heating and warping the plates.
THE CONVERTER... that most of the Airstreams had before the 90's were of the transformer type.. and again had very little regulation... if the shore power input was 132 v ac... then they put out 14.7 volts dc... and again boiled the battery.. if on the other hand the input was 108 v ac then the univolt would only put out about 13.2 volts dc.. not enough to bring the battery to full charge. They were good because they were simple.. and cheap. Most were rated for about 50 amps... which was more than enough for run'n the heater motor and a few lights...
THEN CAME THE NEW TECHNOLOGY... Airstream went to a more effecent switching type converter... but, they had failures... and most either boiled the battery or would not recharge the battery fully. i.e they were junk.
but, they did recharge the battery AND would provide 12 v dc power for the motors and lights. They did do a little better on regulation of the voltages.. but more they were more effecent... (transformer types.. that hummed right along were only rated for about 60% effecent... the new switching types... are rated for over 80% effecent. More a issue was that they could take the 108-132 v ac... and still recharge a battery fully... when they worked right...and were quiet... physically... but not electrically due to the nature of the electronic circuit.
NOW COMES THE NEW KID ON THE BLOCK... Today we have converters that have 4 stages... (sad'ly Airstream hasn't gotten on board with them yet) Some have said that their new ones are 4 stage.. but again failure rates without the owner knowing has been higher than acceptable...
So we did a lot of research on the topic.. when we decided that our old converter had to go... it just made too much physical noise... otherwise than noted above.. it took almost a day to recharge the bats to 90-95%... and that ment that you had to run the gen set for hours on end... etc...
We went with the new progressive dynamics 4 stage converter... its rated at a whopping 80 amps... yahoo... (we will get back to the current ability) First off we found it lighter and smaller than the old unit... has a fan cooling when needed for the BIG loads... (has yet to come on as the unit hardly gets warm at 90% full load)
Its quiet... big factor... and has the 4 charging stages.. of which you can override the auto function and go manual with the external pendent switch.
Ok so what makes these better... well they have the first stage that no matter what the frequency (line current is 60 cycles) will put out its rated voltage.. and current. It works from about 100 volts ac to 137 volts ac.. so that takes care of the campgrounds where everyone is pulling current run'n A/C and you want to get the battery back up to full from boondocking...
Its first level voltage set is at 14.7 volts.. similar to the TV alternator output... it charges the battery up more quickly... where we said the old one takes a day.. this one can bring the battery back up to 90% or so in less than 4 hours. This saves on the genset time or time just waiting for them to get recharged back up from 50% (you never let yours get below 50% DO YOU....) to about 90%...
The second voltage it then goes to is 13.7... now that may not seem like a lot but of voltage drop.. but it does keep the battery from boiling out... and maintains that voltage so that all the appliances in the RV will run at peak.
If no electrical load is being used then the converter (wizzard as I call it) will go to the third stage at 13.2 volts... this is a surface maintenance charge for the battery... it can stay their forever.. well almost... and never hurt the battery..(well kinda) So you can turn this puppy on and leave it forever...(glamping) and not have to do much to maintain the battery.
But, you say.. wait a min you said 4 stages... what is the 4th stage.. Ok... the battery now is on maintenance charge... and has been their for a couple of days.... bad thing can happen inside the battery when it get sedmentary... first off they found through technology. that the battery will cause the more consentrated acid to sink to the bottom of the cell... here it then can start to crystalize... sulfate... (not good) In your TV your battery get subject to physical motion and so the acid in the cell get shook up and mixed... not so in your RV that is glamping.. it just sits their... so what the brainiacks have come up with.. is... to have the converter jump back up to 14.7 volts for about 20 min every 21 hours... according to DPs operating chart..
So what does that do.. well when the battery is fully charged.. or nearly so... at that voltage it will cause the battery to boil... (lightly).. this action is like your perk coffee pot.. it cause the acid at the bottom of the cell to bubble up (in a way) and cause mechanical mixing in the cell... as well as clean the battery plates so that its at peak effecency.
Neat huh... boy wait till Airstream engineers (are they any left) find out about that... only problem is.. they squeek when they walk.. so to speak... and all go around saying cha ching $$$... hate to spend a bux... without out a high return from the buyer...
So you have to go aftermarket to someone like Progressive dynamics and get the 92xx converter if you want the latest and greatest...
Oh and some of the solar controllers have similar stages too now.. as that is the current technology and thinking to max your battery life.
... and we mentioned that this one is 80 amps.. why so much you say... well another technological issue is recharge rate... seems that you will keep the plates in the battery cleaner if you provide them with the max current they can demand... once the battery starts to recover... it start building a higher internal resistance and tapers off in its current demand... If you restrict the amount of current first applied... the battery will not recover as quickly... and it has been found the plates in time will coat out and not provide the current capability it was rated at...
besides... with 80 amps.. I can light up the whole trailer.. inside and out and never put a demand on the battery... where as the current converter in AS are rated for 45-50 amps.. and if you turn everything on... your current demand is up their around 60 amps... so the battery then has to provide the extra 5 amps or so.. in a discharge mode... not what we want when glamping etc...
So their you have the newest of the new thinking and products to improve your electrical issues.. and max your battery life...
Oh if your stor'n your trailer.. /RV... I think it wise to do the old school thing and remove them.. take them home place them on a piece of wood...(old wives tale) and recharge them frequently.. then take them back and put them in the trailer when you are going to use it. (labor intensive) but at todays prices and increases.. you want to optimize your battery life to the max.. after all you can hear cha ching $$$ when you get new ones and never got full usage out of the old ones your lugging into the dealership.
The adventure contenues... WA6CDE
and it is rated at 80 amps... you can pick them up on line for about 230 bux... I found that several mail order places were cheaper than buying it local. 
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