Where is my battery?

[bdosborn]

Hi Bruce

unless you have some kind of special alternator smart regulator, your battery was not fully charged when you returned home, its not actually possible.

I agree its better than nothing (but only just)

12.8 volts. Yup, fully charged per the manufacturer specs for my particular battery. And it was charged the entire way to Minden. It was at 12.8 volts when we got there.
Bruce

[Nitetimes]

You know, travel trailers and work trailers that carry batteries have been charged this way for years with no major problems that I've ever heard of. Most replace there batteries every 3 - 5 years and a lot aren't even bad they just do it before long trip outs. If you are running some 12v light and a small fan and maybe a small inverter I can't possibly imagine why a standard car battery charged off the vehicle wouldn't keep you well suplied even for an extended period of time. I spent a week at Lowes MSW in Oct and all I had was a $25 Wally World battery. We used the lights for hours at a time in the evening for reading the entire week, I didn't even have the charging line hook up on the charging vehicle. And when I got home I put that battery in my truck and it started it.
Most vehicles these days have regulators in the alternator so they don't just keep charging after the battery is full otherwise the battery would dry out and burn up.
I really can't see the justification for $100+ battery and hundreds more in charging devices to charge batteries that you will be lucky to get a few good years out of anyway. Most deep cycles that I've encountered are only good for a few years anyway so why all the fuss. Buy a couple cheap (light by comparison) batteries, charge em from the car and scrap em when they are bad. Even if you changed them every 2 - 3 years your $ output over 10 years will probably be considerably less than the high end setup. Considering the expected life of most electronics these days you'll prolly replace most of those gooies in a few years too.
JMO FWIW Rich

[GeorgeTelford]

Hi Noetimes

It is a known FACT that a standard vehicle alternator cannot fully charge a battery (either a starter or leisure)

For starter batteries its never a problem, a starter battery does 2 things only, one is to start the vehicle (high amperage for very short time) the other is act as a smoothing capacitor for the alternators output.

The starter battery is discharged by a tiny fraction, lets say that the cranking Amps are 300 for 2 seconds, thats a total depletion of .25 Ah, this is soon bought back to original charge (note I do not say fully charged) The rest of the time the alternator supplies the power.

Here is a test I did a few years ago

from fully charged at 12.93v (measured 12 hours after coming off the Sterling charger) connected bulb, it took 6 hours and 17 mins to reach 12.2v (ie flicking over backwards and forwards from 12.3v)

It was then fully recharged on the Sterling, allowed 13 hours to settle the voltage, reading was 12.94v flash 12.93v, the engine on the iveco was started, then I connected the battery using a good solid cable as before and drove this morning for 1 hour 14 mins, as soon as I got back it was connected to the same bulb (55w halogen) connected at 12 : 12 today, it started flashing between 12.3 and 12.2 at 5 : 37 PM today

Same battery, same full charge by Sterling, only difference 1 hour 14 mins of extra "charging" as knocked off 52 mins off usable power !!

Standard batteries vs deep cycle leisure, I tend to agree with you here, most leisure batteries are more hype than content, a proper deep cycle will weigh far more than a standard battery.

Why spend what amounts to a few dollar$ more for a 4 stage deltran?

Charged via alternator the battery gets to 65 % you should not discharge below 50% so out of a 100 Ah battery you got 15 Amps useable (unless you want to fubar the battery in a couple of years max) but consider that 15 amps is 60 Times more than the starter battery ever gets drained when starting the car, thats why the starter lasts it never really gets discharged (unless you leave lights on or have trouble starting)

Anyway back to the deltran (or any 3-4 stage charger) this will charge your battery to 100% so then you have 50 Ah available or 3.33 times more power available.

Hi Bruce

ah I see where you are getting confused now,

If you drive for hours, the voltage when you switch the engine off will stay high for up to 12 hours after you stop, next time you drive back measure the battery the next day there will be a big difference. If 12.8 volts is the fully charged voltage (after 12 hours rest) then after a good run back I will guess that you voltage will be 12.5v ish


Hi Powder

Some of your questions have been answered above.

What a battery will hold is usually written on the side as AH so a starter that says 100 Ah and so called leisure @ 100 Ah hold the same, the leisure should weigh more but rarely does.

Is there a regulator you asked, yes in UK we have Sterling Smart regulator amongst others, this turns an alternator into a 4 stage charger, here is a UK site to the Advanced regulator that I use

http://www.sterling-power.com/htm/ar12vd.htm

Standard alternators are not designed to be good battery chargers; they are designed only to charge an engine start battery sufficiently to start the engine. Because of this inherent design problem associated with the standard regulator, a more advanced regulator is required which in effect converts the alternators from a constant voltage power supply to the latest 4-step constant current battery charger (see battery charger graphs). Because of this improvement in the alternator control system, these regulators dramatically enhance the alternator's charge rates by between 200-2000% depending on how poor the original system is.
The Sterling System is the only real time control system which is in operation 100% of the time. This real time control ensures the high charge cycle is switched off when the batteries are full (regardless of battery bank size or state) and the high charge will automatically reset itself if after the charge has been completed and the output from the batteries exceeds the output from the alternator. Because this is real time-based, this monitoring and control is in operation all the time the engine is running.
The Sterling Regulator is designed to charge batteries as fast as possible and to their maximum capacity without damage to the batteries or alternators. Therefore, we opt for the constant current charging mode and not pulse charging which would double the charge time.


Gotta work now I think I have covered everything

George

[bdosborn]

Hi Bruce

ah I see where you are getting confused now,

If you drive for hours, the voltage when you switch the engine off will stay high for up to 12 hours after you stop, next time you drive back measure the battery the next day there will be a big difference. If 12.8 volts is the fully charged voltage (after 12 hours rest) then after a good run back I will guess that you voltage will be 12.5v ish
George

Nope. I watched the voltage closely while we were in Minden. The voltage on the second day after using the battery the night before was 12.7 volts.
Bruce

[GeorgeTelford]

Then Bruce you must have Magic batteries that defy the laws of physics.

Alternators without an added Advanced Smart regulator do not fully charge lead acid batteries.

Nasa and CalTech are awaiting your call

[Gaston]

I also feel life is too short to be concerned over the last 10th of a volt. I have always used the cheap deep cycle wally world type batteries and I discharge them till the lights wont light, then I charge them with anything handy that puts out at least 12 volts. every 3 or 4 years I trade them in for a couple of new ones on sale. I mostly "dry camp" and rely on the batterys for power and my Honda EU2000 generator for the 110 I might need and to recharge the batteries. the money I saved by not spending it on high priced batteries and charging systems I used to paid for the generator
I also respect those who are concerned about these things, but I find they are usually waxing and bragging while I'm out camping.

[bdosborn]

As noted in Chapter 2, 14.2.14.4 volts output is a compromise. It's high enough to spin the starter motor, but also low enough to prevent overcharging unless the vehicle is driven non-stop for days on end. But that 14.2.14.4 volts output is too low to charge any conventional lead-acid battery beyond 70.75% in any practicable length of time

.

George,

Bear with me for a few more questions. Then I'll call NASA and offer to sell them my magic battery that defies the laws of physics.

Why is 14.4 volts too low to charge a battery? Thats only 0.1V less than my Promarine charger voltage at bulk charge.

I noticed in the quote that the author hedged on his 70-75% statement with

in any practicable length of time

Maybe the 8 hours it took to fully charge my battery by the alternator isn't considered a practible length of time?
Bruce

[GeorgeTelford]

Hi

You could drive 24 hours straight and it still would not get above 70-75%

Alternators are set to "charge" at 13.8-14.2 Volts, but its not just the voltage at play here, the standard regulator reacts, ie battery voltage pulled down (by anything being used) and then alternator gives more power, this is the key factor, a Promarine set at 14.5 is set for Gel and sealed batteries, which need charging at a lower rate, Many chargers are set at this rate by default to "idiot proof" them, so the person who reads the instructions will set them right for the lead acid battery, a lead acid should be set higher @ around 15v big difference. By the way the author lives in Broome Australia bring's a 10 Hour drive to the next town into perspective. and he as driven across Africa system testing vehicles. The electronic test equipment in his own vehicle makes it look like a plane cockpit.

The real proof for me was testing a Known fully charged battery, I put it in my campervan and attached to alternator charging after one and a quarter hours driving it had lost charge,

Here are my notes from that day

from fully charged at 12.93v (measured 12 hours after coming off the Sterling charger) connected bulb, it took 6 hours and 17 mins to reach 12.2v (ie flicking over backwards and forwards from 12.3v)

It was then fully recharged on the Sterling, allowed 13 hours to settle the voltage, reading was 12.94v flash 12.93v, the engine on the iveco was started, then I connected the battery using a good solid cable as before and drove this morning for 1 hour 14 mins, as soon as I got back it was connected to the same bulb (55w halogen) connected at 12 : 12 today, it started flashing between 12.3 and 12.2 at 5 : 37 PM today

Same battery, same full charge by Sterling, only difference 1 hour 14 mins of extra "charging" as knocked off 52 mins off usable power !!

Alternators cannot fully charge a battery, not without a aftermarket smart regulator.

But like powder says you could get by no probs, if all you use is lights and you dont mind replacing battery every year or so and also do not mind that you are getting only a useable 25% of capacity instead of 50% which could mean twice as long camping without having to recharge.......

[bdosborn]

George,

Well, you still have not explained the mechanism by which the battery is not fully charged in a way that makes sense to me. Thanks for taking the time to express your views and I think we should just agree to disagree.
Bruce

[GeorgeTelford]

Hi Bruce

So if you cannot understand it, its not real? Companies make 3 and 4 stage chargers and they then must be a waste of time because Bruce doesnt get it?

Experts the world over say it cant be done, but obviously they are wrong because it doesnt make sense to Bruce?

The experiment I did and outlined above shows that a fully charged battery is actually discharged when connected to vehicle charging system.

Another experiment that I did Connect a discharged battery to a charged one, Measure the settled voltage of each before connecting, leave for 24 hours, then disconect thebatteries from each other, The fully charged will have a lower terminal voltage and the dicscharged battery will now have a higher terminal voltage.

After that experiment I did the same one with the equivilent of a convertor attached, the end result was the same.

[bdosborn]

Aw come on George. We just have a difference of opinions. No need to get nasty about it. Why don't you PM me if you'd like to discuss this more.
Bruce

[madjack]

oh comeon now...just shake hands and go to your respective corners...I truly don't wanna have to move anything...it makes Buford mad at me and I get enough of that at home
madjack

[madjack]

I didnt start it this time MJ.

hey, I know...nobody started anything, it just kinda grew outta difference of opinion
madjack

[Gage]

He, he and I didn't even stir the pot. I just love it.

You know, when I went back to Minden, I was out for 5 weeks and never lost my battery, and it wasn't even hooked to the tow. It had a full charge (or what my charger would give it) when I left home and every time I'd pull into camp I'd hook up the solar panel. I didn't worry about how much charge was in it as long as it provided elec to operate all my bells and whistles.


Have a good day.

The solar panel is a 15 watt. $150 at HF.

[GeorgeTelford]

Hi Powder

That experiment was designed to show that a fully charged battery would lose charge after EXTRA "charging" via the vehicle system. Before both tests the battery was fully charged by the Sterling.

I have highlighted the crucial bit below, I think you have misread how the test was performed.

The battery was charged fully on the sterling then left to rest and then discharged usning a bulb until it reached a predetermined voltage.

The test was then repeated the battery was again fully charged via the sterling charger first, but this time it was attached to a vehicle and driven around for 1 Hour 14 mins so it actually had MORE charging than in the previous test, no the same discharge test was performed, but this time the battery ran down 52 Mins quicker, proving that not only do alternators not fully charge a battery, they will actually discharge a fully charged battery.

Hi Bruce

This is not a matter of opinion, opinion would be "I like blue shirts and you like green", this is a matter of FACT ie like me saying 2+2=4 you saying 2+2= 7.5