Parallax converters

[whitegs]

According to the manual for my OEM Parallax converter, when the battery is "charged", the current throttles back to a "few hundred" milliamps. I have been keeping my group 24 batteries in maintenance mode with a batteryminder. This morning, I flipped the battery disconnect to use since we are going on a trip today. I just got a clamp on ammeter so I thought I'd check to see what the Parallax was sending to the charged batteries. Sure enough, 200 ma. So I'm wondering if this low constant current is enough to account for all the "boiled" batteries we've been reading about. My plan is to use the Parallax for bulk charge and when the current drops to "a few hundred ma", switch to the batteryminder for topping off the charge and then maintenance. If I ruin another set of batteries, then I'll bite the bullet and get a different converter but I'm of an experimental frame of mind.
My original batteries were DOA from the dealer. Interstate gave me two new batteries no questions asked. I bought my AS new.

Richard

[Rich W]

Like a drip in a sink, eventually it will overflow. When a battery is fully charged the charger should stop sending voltage. If you don't keep it plugged in all the time then that type of charger is OK. If you do keep it plugged in then you should consider an upgrade to a multi-stage charger.

[whitegs]

Originally Posted by richw46

Like a drip in a sink, eventually it will overflow. When a battery is fully charged the charger should stop sending voltage. If you don't keep it plugged in all the time then that type of charger is OK. If you do keep it plugged in then you should consider an upgrade to a multi-stage charger.

I guess you mean it should stop sending current. They all seem to apply a float voltage when the batteries are fully charged. I suppose when Parallax says to leave it plugged in with "regular maintenance", they mean check the water level in the batteries. You are right. When my batteryminder goes into maintenance mode, almost no current is flowing.

We'll see. I realize it's not that big a deal to switch out the converter but I'm willing to try my new regimen and see how that goes. Someone in another thread uses the Parallax 2 hours on 4 off 24/7. The downside of just using the Parallax as I understand it is that the voltage never gets high enough to fully charge the battery. My little batteryminder seems to be doing the job correctly. The voltage it provides is over 14 while bulk and absorption charging then drops to a lower maintenance float voltage when the battery is charged. In addition, it claims to be constantly desulfating as well.

If this all works and the batteries survive, it seems a simpler solution than swapping out the converter.

While boondocking, I have two EU2000 Honda generators and a Zamp 160 watt portable solar panel so I'm primarily looking at keeping the batteries up while I'm at home.

[lsbrodsky]

If your plan works for your kind of camping, it should be fine. No one is forcing you to upgrade and you seem well aware of the OEM converter problems.
For me, a new converter allowed a more hands-free solution, especially since we spend most of our camping days plugged in to shore power.

Larry

[Silvertwinkie]

I swapped my converter out about the 4th year I had the trailer (2008). The initial Interstate batteries barely lasted the 4th year.

Since moving to a 3 stage converter, I have had the same batteries in the trailer since 2008 and though age has made them not last nearly as long as they did when I first installed them in 2008, I'm going on 8 years with these two batteries and I attribute that mostly to me no longer cooking the batteries. I last about a week and a half compared to nearly two and a half weeks when new. I think that's pretty darn good for 8 year old batteries.

I do take them out in the fall when I store the trailer, give them a full charge before putting them into the basement for the winter, grab them in spring top them off again, and keep them in the trailer all summer long (mostly plugged into shore power when not in use).

Your results may vary.

[rdepas]

As stated before, you can go with your plan and be just fine, but if you want to be more hands off, then you may want to swap out the converter.

I had the Parallax Series 500 in my 2014 Classic. Bought the AS used a couple months ago and found one of the batteries had a dead cell so I replaced both with new Interstate batteries from Costco. Ran them with the Parallax for a good month leaving the trailer plugged into shore power 100% of the time. About 1.5 weeks ago I replaced the converter with a PD-4655 (not a direct replacement in a Series 500...) It has a Charge Wizard built in indicating the type of charge. Surprisingly the charger was in Normal mode for days. After about 5 days I checked and it was in storage mode finally. Seems to me the Parallax was not doing that great of a job charging the batteries even normally.

That was just my findings and I was very happy to throw a couple hundred at a better converter to run my 12v power in the trailer and charge my batteries better. Even if it only saves me one extra cycle of swapping out batteries over the life of the trailer, I break even. The piece of mind it gives me is a bonus. Even with the heavy mods I had to do, I had the project done in about 4 hours.

[Rich W]

[QUOTE=whitegs;1824589]I guess you mean it should stop sending current. They all seem to apply a float voltage when the batteries are fully charged. I suppose when Parallax says to leave it plugged in with "regular maintenance", they mean check the water level in the batteries. You are right. When my batteryminder goes into maintenance mode, almost no current is flowing.
QUOTE]

Yes, I tend to mix the two which I shouldn't do. But the charger shouldn't be putting anything else into the batteries if the batteries are fully charged, it will only boil out the water (acid) over time. It may take a while but with insufficient drain on them they will just boil. I lost several sets of batteries in my bass boat when using a portable charger that utilized a trickle/float charge. Years ago I bought a 3-bank, 15 amp, independent charger that cuts off each battery after it reaches full charge. That way each battery gets what it needs and one battery doesn't control the charge rate for the other two. The result is that my batteries last for many years.

I replaced the Parallax in my AS, mostly because it had failed and wasn't providing much of any charge. The PD-4655 was an easy swap. I keep my AS in a storage lot so no worry about overcharging. The solar panel keeps it topped off.

For my use, if the Parallax hadn't gone belly up, I probably wouldn't have upgraded.

[rocco52]

I was wondering how the constant draw of the Propane Leak Detector factors in here? Is that the cause of the 200 ma charge?

[Rich W]

Originally Posted by rocco52

I was wondering how the constant draw of the Propane Leak Detector factors in here? Is that the cause of the 200 ma charge?

It's a drain, for sure. I don't know the draw but over time it can drain the batteries, others have reported that here. If you don't have a solar panel nor keep it on the charger, you need to disconnect the battery manually or install a switch to open the connection.

[rocco52]

I don't know if this is the best way to do it or not but I leave it plugged in all the time. I switch the Batteries to "Use" for a couple days a week to charge them. Once a month I hook up my Multistage Charger to the batteries and give them the full treatment. Ironically I have only had to add water once and that was after I picked it up from the dealer new.

[Jammer]

Originally Posted by whitegs

....I thought I'd check to see what the Parallax was sending to the charged batteries. Sure enough, 200 ma. So I'm wondering if this low constant current is enough to account for all the "boiled" batteries we've been reading about.

So, we're talking about recent Parallax converters (last ten years). Old ones were different.

I still have the much-maligned stock converter in my trailer. It has its limitations, but the problems with it overcharging batteries are, in general, greatly exaggerated. My batteries are six years old, they work great, and I leave the converter plugged in while the trailer is in storage.

I've made measurements also.

There are two things to understand relative to overcharging and battery longevitiy:
1) The Parallax is NOT temperature compensated.
2) Water your batteries.

Because the Parallax is not temperature compensated, it will overcharge batteries in hot weather and undercharge them in cold weather. On the hot side of things, this becomes a fairly serious problem when battery temperatures get up to around 90 degrees or more and stay there. On the cold side of things, below 50 degrees or so, the batteries won't fully charge.

The battery minder you're using isn't temperature compensated, either, so it has the same limitations, although perhaps combined with a lower maximum output current, which maybe helps.

The way you deal with this is you keep the electrolyte level above the tops of the plates in the batteries. In hot weather, get out your distilled water, check the batteries, and top them off. If it's really hot you might have to do this every two weeks, but I find that a couple times over the course of the summer is enough.

Slight overcharging won't hurt the batteries as long as the electrolyte is topped off before it gets to the tops of the plates.

Now, all that said, the Parallax has other problems, namely the fan runs too often and it takes a good 16 hours to fully charge the batteries, but I can live with those, and do.