newbie battery and electrical question

Roman Duck wrote:
Ac units might run at a 10 amp draw atfer start up, but will need more amps to draw at initial start up. I'd be very interested in a 12 volt AC, What brand makes a 12 volt?. How many BTUs will the a/c produce?. I'm sure that there is a relationship between btus and amp draw
I'm not profiecent at any of this, but intend to follow your thread.
Please post your conclusions, and performance on your final system.
Be great if you can run all needed, on batteries for 24 hrs before recharging.
Good luck!

although i was wrong intially about the amp draw of air conditioners, i did find a few things that DOES run on 12v dc.

first thing is 12-24v air conditioners that are made for semi trucks, i didn't find any info on BTU, amp draw, and pricing. but most of them claim it will maintain a comfortable temp and run on ~3 or 4 group 31 batteries(that's about 400Ah battery bank) for a full night.
as far as pricing goes, i am afraid it can be very expensive because they all don't list a price but keeps saying truckers can save $8000 per year for not idling the engine all night long.
here is a list of what i found http://www.csswebform.org/webform/supplier_list.aspx#BACs

another thing, not very ideal but most doable, is a 12v portable "AC" that runs off ice(basically a cooler with a fan i think) which only draws 1.6 amp and cost $430.
when i was travelling in my VW i had a cooler and was refilling ice every other couple of days, which wasn't much of a hassle. and now i do have a fridge, i should be able to keep a few days worth of ice easily. then i will be able to dry camp on 200ah of batteries for 2 days.

Arizona Kid wrote:
I believe this is your quote that Booster is referring to.

"AGMs do not require a multistage charger, and certainly NOT a 4 stage. Stage 4 is usually a high voltage stage designed for flooded batteries to stir the liquid. AGM's acid does not stratify and actually cannot be stirred."

As well as this response when I disagreed with your statement about not needing a multistep charger.

My statement:

I would not agree that AGM batteries don't require a multistep charger. Lifeline is even recommending equalizing now. While it is true that they will charge off a single step, they will not charge the best, and not last as long. They will also not get totally full as quickly as they would with a proper multistep. If batteries aren't charged to a full 100% on a regular basis, they lose capacity fairly quickly.

Yours:

"I am quite familiar with the Lifeline manual and often cite and quote from it with links, page, and paragraph numbers.

Could you tell where in their manuals you have found the above claims?"

And here:

"AGMs are drop in replacements for starting batteries. Therefore, yes, AGMs can be charged by any regular alternator or automotive charger."

Sure sounds like a push for a single step to me.

I did miss the links, as most folks would put the link on the name of the charger, not the price. My bad.

I believe this is your quote that Booster is referring to.

"AGMs do not require a multistage charger, and certainly NOT a 4 stage. Stage 4 is usually a high voltage stage designed for flooded batteries to stir the liquid. AGM's acid does not stratify and actually cannot be stirred."

fttang wrote:


so i found the energizer brand group 31 AGM battery on sam's club website, but they want $200 for it at the local club, and there is 9.5% tax, probably core charge as well...
seems a little pricey, wondering if there are other source for purchasing batteries.

That is the rebadged Johnson Controls battery that I see in OK and TX. As far as $ go, here is a link to another source with comparable prices, free shipping and no core charge.

HTH;
John

full_mosey wrote:

fttang wrote:

...
so the same club one is AGM then?
i couldn't find it on their website, could you give me the brand and model?

Sorry, I missed your post as I had just left for a round of Golf.

In the Eastern states you get:
Rebadged Deka/East-Penn. This is my preferred brand.

In Western states you get:
Johnson Controls. I have seen these in OK and TX Sams Club stores. I have nothing against these.

I hope to hold off for a family reunion this summer in TN so I can replace all three of my house AGMs with the Deka mfgrd ones.

HTH;
John

so i found the energizer brand group 31 AGM battery on sam's club website, but they want $200 for it at the local club, and there is 9.5% tax, probably core charge as well...
seems a little pricey, wondering if there are other source for purchasing batteries.

booster wrote:
OK lets go through this.

...

I don't see anything to go through!

I recommended a multistage charger with temp comp. I have no idea why you can't see the model info, but if you were to click the link I have twice provided, you might see 4455TC. I believe that charger is compatible with any AGM mfgrs specs.

I have never recommended a single stage charger, nor claimed that one is preferred. Quote me if I did.

I would appreciate it if you would cease mis-stating me and then challenging me on things I never said.

HTH;
John

OK lets go through this.

You strongly disagree with the statements about multistep chargers and insist on supporting data (which was given proving the statements) for mutistep chargers being the charger of choice for Lifeline, claim that a single step charger is fine for AGMs based on the recommendation they can be used as starters (more on that later), recommend an AGM and single step charger to the OP, claim that Lifeline says single step chargers are good (with no supporting data), and then wonder at the choice of words that indicate you are saying a single step is the "preferred" charger per Lifeline. That is stretching semantics way to far from intent.

I have been unable to find any information from AGM folks that say it is OK to use a single step charger, unless you manually watch it, time, measure amps, and disconnect when needed. I would like to see some.

The size of the chargers on the Lifeline link is not the issue that they were posted for. They were, and do, show that Lifeline recommends multistep chargers, not singles. What is the point?

If you use a single step, what voltage do you chose. 13.5v will leave you undercharged and losing capacity. 14.4v, which the manufacturers want to get the batteries full, will dry out the electrolyte if left on full batteries, and lose you capacity. Voltage in between, best/worst of both? Multistep takes care of that for you.

How about the fact that manufacturers will say it is OK to use an AGM as a starting battery, and be charged by the vehicle alternator, so it is OK on a single step charge when used as a coach battery? These are two separate, and distinct, applications, and shouldn't be lumped together, IMO, and from discussions with Lifeline, Deka, Optima, and Trojan over the last 30 years, they consider them different also. Optima is the primary one recommending using them for starters, and claim a higher voltage tolerance than the other brands, up to 15 volts, but they throw in a battery temp disclaimer. I specifically asked about how they do it, and they wouldn't say (not surprising), but it probably has to do with heat dissipation (they have lower AH for their size than most), and they may have a voltage limiter in them. Regardless of that, I asked about the electrolyte dry out issue at the 14.4+ volts vehicles now run (our hotrod, that we use an Optima in, runs at 13.8 volts like most older stuff), and they said it would be an issue if the battery saw the voltage for very long times, but the way vehicles are used in real life, they rarely get the battery totally full, much less full and held there with the high voltage for long periods, so it turns out to not be an issue, except in a very few special cases. That makes perfect sense to me. Use in an RV, at least the way many folks use it, would not be the same. If you have a separator, and come off shore power, all your batteries are full, and could easily see high alternator voltage for 12+ hours of driving, which could easily be damaging, both for the starter and coach batteries, at least according to the techs I talked to. A battery disconnect was recommended to me when I considered AGMs when I increased our battery bank size. Using one for the starter, was not recommended. Boats that are motored a lot, and thus see a lot of alternator voltage, often use a 12v to 12v multistep chargers to address the issue. A single step charger would have all the same issues as a long drive, if it was set at the battery manufacturer recommended voltage of 14.1-14.4 volts (most common). Many, many, folks (us included) leave our RVs plugged in at home for weeks at a time. How do you handle that with a single step charger?

You didn't give a model number for he Parallax charger, but when I look at them, most look to be power supplies set at about 13.6 volts, which is too low to fill batteries completely. Some have a "boost" mode, which takes them to the appropriate higher voltage to get a good full charge, but those are multistep, albeit manually, chargers, so you would say they are not needed.

I don't think you would get any AGM manufacturer to recommend using a single step charger in these kind of applications, unless you had a fixed discharge every cycle and fixed recharge time, with a fixed bank size. I would love to hear if you have a source that would.

booster wrote:

...
Here are the chargers that Lifeline recommends, even puts their name on. Note the many comments in the text about proper charging parameters and increased battery life. Ctek chargers are something like 6 step chargers.

Lifeline charger recommendations

...

You might find it interesting that none of those chargers would be appropriate for a 220AH pair of 6Vs. The largest 7000 model is only recommended up to 150AH. There is a big difference between cyclical and standby charging. None of the cited chargers are adequate for cyclical charging because they fall below the minimum 0.2C charge rate in 5.4 charging. Also note they lack temp comp!

Again, I recommended an appropriate charger for cyclical/RV use.

HTH;
John

booster wrote:
Full mosey,

Have you had a chance to find information from Lifeline that discusses the issue of if a single stage charger is the preferred one for their products?

If single stage is the right charger, many, many, of of us have been giving a lot of folks a lot of bad advice for a long time and need to know that.

If the single stage is not the best recommendation the OP needs to know that, so he can make a good decision for his project.

Could you please quote me stating that a single stage charger is PREFERRED. If I actually said that, it would be a mistake on my part and I would like to go back and edit that posting.

I did recommend a proper charger, namely, the Parallax Powermode charger for around $175.

HTH;
John

Full mosey,

Have you had a chance to find information from Lifeline that discusses the issue of if a single stage charger is the preferred one for their products?

If single stage is the right charger, many, many, of of us have been giving a lot of folks a lot of bad advice for a long time and need to know that.

If the single stage is not the best recommendation the OP needs to know that, so he can make a good decision for his project.