External battery charger

[Seamutt]

Now and again I use an external three stage battery charger on my two 6 volts without disconnecting the batteries from the trailer. I have not had any issues so far but was recently told not a good idea, that I should disconnect first before using the external charger.

Any thoughts on this?

[landyacht318]

Are we arguing over whether a charger can get a starting battery charged enough to start a vehicle, or whether it can indeed fully charge a deeply cycled battery?

Why not throw another variable into the mix and make the battery one which is still hooked to loads, perhaps cycling loads like a compressor fridge.

I've not doubt and charger can charge a battery enough to start an engine, I've huge doubts that when it drops to float mode, that the depleted starting marine/deepcycle battery battery is indeed fully charged, or anywhere near it in some cases.

Most of the public will only throw a charger on a starting battery when it has failed to start their engine, and such a battery needs absorption voltage to be held for longer, and the regular automatic smart charger is not going to do this, yet that green light will easily convince the user that it did, and because the engine started, it worked right?

On this forum many people know the key to keeping a lead acid battery happy is charging it until it is 100% charged, regularly.
Automatic chargers which can claim to do this, but cannot, are not doing anyone any favors, no matter how much faith one has in their purchase or the product's marketing, or how badly they want to believe the marketing, or how many people they can get to agree with their purchase/decision.

Perhaps such people's ancestors were the first to line up to listen to the snake oil salesman's pitch.

[westend]

Wotta hoot. The era of rationalization.

I know a guy that has a vacuum cleaner with an indicator light on the cowl. It tells him when the floor is clean.:B

[MEXICOWANDERER]

Any charger with a design motif of the Chrysler building, pwetty bwinking wights, a gold tone mylar label that screams PULSE RECONDITIONING is going to sell like hotcakes.

"BAAAAAAAAAAH!" Here's the wool gimme my miracle.

Battery OEMs are loving it.

Oh it don't work? Say wait a minute did I hear a howl? That overly large ewe's got zippers! It's a setup!

Like eating fastfood. Plug n play. Everyone's doing it. No one has the time anymore. Or the energy. Whaddya mean he's dead? He was only fifty-four! Must have been overworked!

Wotta hoot. The era of rationalization.

[time2roll]

landyacht318 wrote:
I'm gonna put my Schumacher back together and let it loose on my screwy31, then after it flashes the soothing green light, supposing it does not goto 16.4v or higher and shut itself off, and see how many more AH my Meanwell can stuff into it before Sg no longer rises.

Ah never mind, whats the point? Actual Data means nothing, compared to a marketing page and blinking green lights, to somebody defending their purchase and their misplaced faith.

The real test data will be if the battery starts your car or boat after the light turns green.
In most cases, assuming the battery is good, the charger will work and the person can go play.

Nobody is going to be running around with a hydrometer to first check if the boat will start except maybe a few purists.

[landyacht318]

What I find irritating about automatic anything, is the marketing. 'Super duper whizz bang does everything but hook up the cords for you!!'

100% fully charging a battery requires absorption voltage be held for long enough. This is a moving target different for every battery, different as it ages and different for temperature and different depending on how depleted it was yet all the marketing pages claim to restore and fully charge automatically and recondition and wipe your heiney for you too.

A one size fits all automatic approach is insulting, to me, but perhaps soothing to those who really do not know, or care to know.

Blinking green lights is all that matters, and something to complain about when the battery fails. Indignation is the new black.

I'm gonna put my Schumacher back together and let it loose on my screwy31, then after it flashes the soothing green light, supposing it does not goto 16.4v or higher and shut itself off, and see how many more AH my Meanwell can stuff into it before Sg no longer rises.

Ah never mind, whats the point? Actual Data means nothing, compared to a marketing page and blinking green lights, to somebody defending their purchase and their misplaced faith.

[Byrogie]

Wow, good thing my megawatt arrived yesterday. I am no longer in "that" group.

[MEXICOWANDERER]

OK prepare to smile
Here comes the sarcasm...

"Oh mannnn! I only gots so much memory. If I have to remember to do stuff I'll forget where I hid the bong!"

"Whaddya mean dess-e-mals? Periods go on the end of sentences not in the middle of a perfectly good number. Oh yeah, speaking of numbers..."

"Mess with a battery? Me? Are you nuts? Hmmm nuts - I've got the munchies reaal baaad"

"Uh what were we talking about?"

The demise of the camper and rise of drivers who tow Fifth Avenue Penthouses for an "outing" is sad. These folks have become disconnected from reality. Utterly severed. I see and I read about folks who drive hundreds of miles, pay enormous rentals then hole-up inside having verbal brawls over a misplaced satellite TV remote or moaning that the A/C temp in the living room is a chilly 68F while back in the bathroom it is near eighty. God Help Us! We have a legion of millions of (another name for cats). Don't want to do this.....might miss my episode of.....why the hell can't I get the awning tube light the partcular shade of blue I like?"

Maybe it was riding fence at age 11, in Montana, or taking a total of 43 pack trips way back into the furthest reaches of the Sierra Nevada wilderness, today's obsession with demanding a LAY-Z-BOY when "roughing it" is beyond my comprehension. The insult of having a person less intelligent than I "Think For Me" is intolerable. Has America become a nation of Sheeple? When I went to find a high power battery chargers and found nothing but child-safe imposters with training wheels, this scares me. Sheeple vote. This is akin to Armageddon.

But my excuse is I have definitely lived too long. Thankfully down here a person must think or pay a heavy price.

-End Commentary-

[time2roll]

The automatics solve more issues for the general public than they create.
JMHO

Old school works too but those that have attended are far and few between.

[MNtundraRet]

There are some really good portable multi - stage chargers with high amp rate charging that have dissapeared from the market in the last 2 years.

Blame the "mommy " generation for suing manufacturers for their own stupid mistakes in how they misuse equipment.

There are way too many electronic devices created to be recharged or used on shorepower. Manufacturers never concidered usage in RV 's .

Any method used to desulfate or properly speed charge a battery (including Mex's favorate methods) requires common sense. Disconnect the battery -bank from the 12 volt circuits while using these chargers.

Otherwise use the charger that came with the RV. Safe for "clueless " use and on equipment installed in newer RV 's but not the best for long term life of batteries.

[red31]

MEXICOWANDERER wrote:
But answer me this point What is the difference between a smart battery charger and a smart converter when boondocking?

One is portable, holds ~14.4+v abs voltage constant till the generator is turned off.

One is available at wally, frys and big box 'hardware' stores.

I can't remember if my xantrex that later became vetor - b&D - bacus global kept sg up to spec but it was useful after a few years of shaded maintainer panel and battery abuse, the 'condition' cycle got the unequal cell d-amn near the others.

[landyacht318]

Even if 16.4 volts might be safe for electronics still attached to the battery, I don't want some charger blasting past 14.5 volts and putting out its maximum power until the battery gets to 16.4v Like My Schumacher does, Sometimes, whenever it decides to, randomly.

Not on any battery I care about anyway.

Other times it flashes the green light and gives up when the battery still requires 5 amps to be held at 13.2v.

A single battery accepting 5 amps at 13.2v is anything but fully charged.

But the 'just fine, green light brigade' only need to see a green light, to declare it is just fine and to 'follow me over the cliff!'

Shame when they give advice.
Bigger shame when others take it.

[MEXICOWANDERER]

What did WE do in the 50's the 60's the 70's the eighties and nineties when we had to charge batteries? Remember this is about CHARGERS not converters. Think a few hundred thousand campers RUINED their batteries every camping trip. Or ran back to a physiciatrist because the camping trip was "ruined" because batteries needed to be charged manually? Charger! Read the title of the thread if you will. Not converter. Oranges and road apples. We seniors could spin a timer dial on a charger while youngers are incapable of vizualizing the concept? We got along just fine without a Pakistani programmed Chinese IC tring to think for us. Fifty years ago when I shut off the charger the battery was 100% full, not 83% full or 69% full. You start percentling battery bank capacity and suddenly you find you are hauling around 80 pounds of dead weight with a bigger bank. Again in hopes of making a seeming fuzzy subject clear a battery charger is NOT a converter. But answer me this point What is the difference between a smart battery charger and a smart converter when boondocking? While people play pinchy-giggle and pin the wanger on the donkey with smart chargers to get them to do anything, I twist a dial and walk off.

[grizzzman]

RJsfishin wrote:
How many times have we heard of some hi voltage from an automotive charger killing any of our electronics, except maybe some cheap led lite that should never have been bought in the 1st place.
I also have a Schumacher charger that goes over 16 volts on most any battery I stick it on. But it has not caused any problem. Why ? Probably because it is an automotive charger made for vehicles whose electronics that can handle some 16+ volts now and then,....maybe forever. If they were to fry electronics, don't you think there would have been a recall on them ? DUH!!
I will add that I have had 2 cheap defective solar controllers pump out 17+ volts for who knows how long before I noticed it. And it hasn't hurt any control boards, or anything else that I know of.

The answer to the OP question (read his lips) is keep doing what you are doing !! Automotive smart chargers mommies didn't raise no dummies !

I have been in the automotive industry for over 40 years specializing
In electrical/electronics. I have seen high voltage (18 plus) with no harm to other systems. Here is a clip of a RV Domestic frig diagnostics manuel.

The Dometic control system will only tolerate up to 6 AC volts on the DC line. AC ripple can be measured by a digital voltmeter set on the AC scale at the main DC terminal block connections at the refer. Six volts AC or less is acceptable. If AC volts exceed 6 on the DC incoming line the power source should be cleaned up. AC voltage in excess of 6 volts will affect the processor and create erratic operation. When testing for AC ripple on the DC line put a load on the converter. The operational range of the unit is a minimum of 9.6V DC to a maximum of 22V DC. The unit will automatically shut down until voltage has decreased to 18V DC. The refrigerator requires at least 9.6V DC for proper operation; however the panel lights will continue to illuminate until voltage has dropped to 4V DC or below.

Just sayin..............

[CJW8]

To the OP, no it will not hurt anything as long as the "never exceed voltage" mentioned above is observed. The charge profiles from the automotive charger and the converter will most likely be different so one charger will fool the other but it will not hurt a thing.

MEXICOWANDERER wrote:
Smart "chargers" are designed to be SOLD to dummies, and others who refuse to do what had been done for the last 100 years with lead acid batteries. PT Barnum put it best.

I respectfully take exception to this statement. I do not consider myself a dummy and apparently my employer doesn't either because they pay me a lot of money to take care of a lot of electronic equipment. I respect your knowledge and experience and have learned a lot from you. Just because I chose to use a smart charger does not reflect on my level of intelligence at all. It is a decision based on available time to tend to my batteries and time to work and camp and enjoy life. It is a compromise. There is a vast number of "uninformed" RV owners out there that benefit from the features of a smart charger but that doesn't make them dummys. They have jobs, wives, children and an occasional weekend to go camping. They do not have time to charge their batteries with an adjustable power supply with SG meter in hand. So what if their batteries only last 3-4 years instead of 6-8? They won't be laying on their death bed thinking "I wish I'd taken better care of my batteries". Hopefully they'll be remembering the camping trips they enjoyed.