Visit our Popular Forums

68 Overlander · 02-05-2007, 10:30 PM

The Parallax 4455TC (Temperature Compensation) 55 Amp multistage converter is now available.

markdoane · 02-06-2007, 04:19 PM

Too late. Already bought the Intellipower. Are you goning to stock them, or is it special order.

http://www.airforums.com/forums/164203-post4.html

68 Overlander · 02-06-2007, 05:17 PM

They are in stock, at least today they are. ParaMode

markdoane · 02-06-2007, 05:43 PM

Randy,

Gotta question the usefulness of this unit. It senses ambient temperature and adjusts charging voltage.

What I need is one that senses the battery temperature and adjusts charger amperage.

68 Overlander · 02-06-2007, 06:08 PM

Don,
I'd like to know more about what you mean.
Voltage is what gasses batteries, the internal resistance stops the amperage. 13.8 VDC @ 75 degrees is a common standard and needs adjusted from there.
That is why 13.2 is selected for float by the other multistage units...to cover all climates. Truth is it's too low for most climates.
14.4 for boost could be increased a little too for northern climates but the risk of burning up circuit boards and excessive gassing in the southern climates prevents it.

markdoane · 02-06-2007, 07:19 PM

Randy,

I guess I'd be worried about a fully discharged Grp 24 battery, say around 10.5V, sucking in 40 or 50 amps and overheating. If it had a temperature limitter, the charger could shut down or throttle back before the plates warped or the case cracked. I've had some batteries get pretty hot while charging and start spitting acid.

68 Overlander · 02-06-2007, 08:29 PM

I'm not aware of a temperature limited converter.
Temperature compensation applies to the voltage only. Those same 40 or 50 amps you are referring to would be present in any converter if the battery resistance was low enough to allow it. Coupled with a non voltage regulated charger such as the univolt, yep I can see it getting hot.
We do have a "soft start" battery charger that lowers the initial voltage and charge rate for dead or neglected batteries until it reaches 10.5 volts before fully charging at the normal rate. If it doesn't hit 10.5 within a predetermined time, it rejects the battery and then you know to recycle it for sure.
I don't recommend letting your battery ever get down to 10.5 volts but I know it happens on accident occasionally.

markdoane · 02-06-2007, 09:10 PM

Randy,

Most of the temperature compensating chargers that I found by googling adjust voltage based on electrolyte temperature. I guess adjusting the voltage has the same effect of reducing the amps by lowering the voltage as the temperature rises.

Most of them do sense the temperature right on the battery, usually by mounting a thermister on one of the battery posts.

Here is one by Cummins in Minneapolis. I didn't see any that were set up primarily as converters. http://www.cumminspower.com/www/comm.../na/s-1470.pdf

I also saw somewhere that VRLA batteries should be kept below 100F, and wet cells below 125F.

68 Overlander · 02-06-2007, 10:14 PM

I too think that would be ideal but how are we going to measure the electrolyte temp?
The Paramode uses a sensor that is designed to be connected to the post of the battery just like you said. If there were an adapter to submerge it, yeah but I've never seen one. The cable is 20-30 feet long.
If I could totally control the temperature of my batteries, I would maintain them at 70 degrees. It briefs well but just isn't the case in most applications.
If fact, there is not too many RVs out there that have any control over the ambient temperature of the batteries since they must be installed in a ventilated compartment and that compartment is not usually centrally heated or cooled. VRLAs need to be vented too.
I like the specs on that Cummins you linked too but like you said, it's not a converter nor does it have the power to manage an RV. Isn't that the same company that travels the country in Semi trucks selling other tools?
I have not read that VRLAs need to be kept below 100 but I think it would maximize their performance too. We used to subject them to everything in the military and they are in Iraq as we speak enclosed in hot compartments. Probably not good for them but what do you do.
Good stuff, thanks.

markdoane · 02-07-2007, 07:51 AM

Quote:

Originally Posted by 68 Overlander

The Paramode uses a sensor that is designed to be connected to the post of the battery just like you said. .

I guess I misinterpreted the leaflet. If it has a remote temperature sensor that can be mounted on the battery post then I'm a happy camper.

I thought ambient temperature meant a more general temperature reading, like in the battery compartment.

nbk3ad2 · 02-07-2007, 07:49 PM

You guys here are all Rivet Masters and I bow to you....

I'm being brave here asking what will probably be a very dumb question. Because I am so new to these things, I get very nervous about "boiling" a battery or other such disastrous event. This thread was started over the introduction of a new converter/charger. Is this new technology I should consider for my restoration? I have been leaning toward the Intelipower 9180 with the charge wizard to power/charge two 6volt AGM batteries. I understand it to be a multistage charger that regulates its voltage automatically as needed - how does it do that? What would be the best setup for me as I will be living in the trailer for about six months and then have it in storage for several weeks at a time?

I greatly appreciate the help...thanks in advance!

68 Overlander · 02-07-2007, 10:01 PM

Hi, I don't see your name so I hope it okay to call you nbk.
Don't be afraid to ask questions. The new converter is just that, another option and not to be construed as the best for your situation. I like the 9180 too but that is way overkill for a 24 footer unless you have a huge battery bank or a rock band.
Two 6 volts is not huge although the AGMs will accept a higher charge rate.
Look in the 45-55 Amp range so you don't have to worry about additional wiring to handle such a large unit. The 80 amp will not hurt anything if the wiring is at least 4 AWG to the battery but it's still overkill.
The new unit above has the ability to adjust it voltage based on the temperature but you can see all of that, so no need to rewrite all of it but it does have some advantages.
The buzz (no pun) in converters is multistage charging and most everybody agrees they take better care of your battery.

nbk3ad2 · 02-07-2007, 10:16 PM

Thanks Randy,

My name is Brandon by the way. I appreciate the input - the knowledge I've gained so far from this site has been invaluable and I'm sure that I'll be asking many more questions along the way.

To give you an idea of my approach, I intend to live out of this trailer for spurts of up to six months at times and want it to be as much like a home as possible. I will not be boondocking regularly but still wish to be able to do it comfortably. I plan on installing all new appliances, a car stereo system with amp/subwoofer (switchable of course), 23" lcd tv (and run a satellite dish/receiver), and have enough power to run/charge a Powerbook laptop and a 20" imac (for the "bedroom"). I am also putting in lots of additional lighting (LED if I can find what i want), a 800w microwave, 15k Carrier A/C (I live in South Carolina) and possibly a 120v Washer/Dryer combo (they're really cool and only 24" wide by 30" tall). Obviously I want the entire system to be as much 12v as possible and the sensitive electonics will run on a small inverter to give cleaner power (400w should do it easily). I have a Honda EU3000 generator to run things when boondocking and am aware that when doing so I won't be able to run all those things.

What would YOUR recommendation be for me? Batteries? Converter/Charger? Small Inverter? The "buzz" around this forum is that you are really good with this stuff. I've checked out your websites and learned alot also. Thanks again for the help.

68 Overlander · 02-07-2007, 11:34 PM

I was kidding about the rock band comment but it appears you have the Stones traveling with you!
I'm a little too humble to just list what we have in that order and suggest it is the only or best option but I can say we have outfitted hundreds of similar scenarios and can make it happen. You might need some on site help too to make it all work.
All you need is the ability to run the DC load (Converter/charger) and inverter connected to the batteries for the AC items when you boondock. So far we only sell one Pure Sine Inverter and there is a reason. Sensitive electronics need true sine and we have the 600 watt (800 surge) WFCO with AC pass-thru and remote. It also works as an uninterupptible power supply (UPS). The big units exceed the cost of a decent quiet generator.
If you blow dry your hair, run the toaster oven, or need to use the microwave when boon docking, it is not large enough unless you fire up that generator. Anything that uses heat will tax your batteries quick with an inverter.

nbk3ad2 · 02-08-2007, 02:54 PM

Thanks again Randy,

I'm with you on the Pure Sine Wave thing and was already looking at the WFCO - pure luck I assure you! My only other question regarding a smaller inverter is that you mentioned the WFCO has AC pass thru - what is that? Does that mean that when I'm connected to shore power, the inverter will still regulate the voltage and produce the pure sine I need? My biggest fear is some trailer hookup frying all of my expensive stuff.

68 Overlander · 02-08-2007, 03:00 PM

Brandon,
Not quite. When shore power is sensed, it stops inverting and whatever you had connected to it is now powered by shore power. The inverse is true, if you lost shore power, it automatically starts inverting to prevent a hard shutdown on your electronics (UPS)
Typical campground power is clean however occasionally the voltage is a little low. If you suspected low voltage, you could disconnect and use the inverter or purchase a voltage booster but those get expensive.

nbk3ad2 · 02-08-2007, 06:13 PM

Randy, seeing as I've already completely thrown the budget out the window, is there any special recommendations on voltage boosters?

68 Overlander · 02-08-2007, 07:04 PM

Not really because I think they are overpriced for the value. I mean, for 3-4 hundred bucks, they don't make much sense to me. First you have to have low voltage which is easy to check with a simple plug in voltage checker. I do it every time I hook up at a campground. I've found less than 110 once but that's just me, some see it more often. Most people don't even check and get away with it for 30 years.
If by chance I found extremely low voltage, I'd wouldn't even lower the stabilizers or unhitch. If the campground could not fix it in 10 minutes, I'd move on. Granted sometimes the voltage drops later after you are all set up but it's easy to detect so I don't worry about it.
I run with a small generator too but never run it at a campground. It would be hard for the manager to ask me to shut it down if I showed him or her less than 105 coming from their pedestal.

68 Overlander · 03-06-2007, 10:38 PM

After I posted I realized I was probably naive and stubborn. We have not had a problem with low voltage to date but Doug at Franks Electronics explained the numbers and the problems. Low voltage is more of a problem than we realized but I'd like to hear your experiences over the years. We took them on.

guy99 · 03-07-2007, 10:54 AM

Interesting topic.

I recently purchased an autoformer (unfortunately not from Randy because he didn't have them on his site at the time).

I resisted buying one for a long time. My thinking had been that it was an expensive accessory with limited real value.

Then my two year old PD9180 failed while we were camping with overnight temps in the teens. The voltage at the park where this occurred was fine but I began to wonder why the converter failed. I still don't know that operating off of low voltage had anything to do with it but there is nothing else (controllable by me) that I can think of.

At home we have a RV site with 50 AMP power, sewer connection, and water. When the MH is parked there it has high quality power, but often I park the MH on a different part of the property and run a long extension cord to run the refer and keep the batteries charged. Often the voltage is marginal. Also while traveling cross country I have often encountered parks where the power seems OK when you first hook up, but then gets lower as you add loads. So, following the law of least regrets, I bought an autoformer while in Quartzsite. I was immediately able to put it to use to boost the voltage I was getting from a friends rig when he was running his generator (thus we were both charging our batteries but running only one generator).