Deep cycle battery test results

I don't quite get your drift, Bonz. The batteries in question were 100 AH and 60 AH, not 100 amp and 60 amp. Also the consumption you calculated should in amps (to measure 'average draw') not AH (which measures total draw over a period).
But, more important, you cannot calculate average battery draw by total nominal capacity (160 AH) divided by total operating hours (9 days at 24hrs, or 210 hrs), because the total capacity (in this case 160 AH) is not all available. Any battery I know of will cease to power anything long before it reaches zero: the voltage will collapse well before it has supplied its nominal AH capacity.
But I agree with you that the system performed well.

But.....if you want good service out of the batteries.......after they reached 12V, then thats when the test should have stopped !!

But still, it will serve you well for what you want out of it !!

3 days to recharge ?? ....you must be running a small charger ??

Hey Tenpounder. If you assume that the capacity of the battery is available and that it is exhausted when the batteries die then, 160AH is available and that was exhausted after 210 hours wich averages out at 0.8 amps per hour roughly.

One would assume that a 100AH battery would deliver 100 amps for one hour or 1 amp for 100 hours and that would be the delivery of the battery.

Yer I means amps per hour not amphours, you're right

That's exactly my point, Bonz. My understanding is that you can't assume 100% of the nominal capacity of a battery is actually available. The experts can explain the science, but my understanding is that, if you try to run batteries down to zero (like 100 hrs at 1 amp out of a 100 AH battery), you'll end up with (a) a surprising lack of power, like warm frozen food, and (b) stuffed batteries.

I reckon its more like a SWL rating. The battery will actually deliver more than the 100AH but is rated such that it will deliver that much and then further drain will deteriorate the battery and eventually kill it prematurely.

That would also explain why the maths didnt work out

Bonz. I'm an economist: the maths ALWAYS works out, as long as you spend enough time fudging the figures.
PS I've just bought 2 new Deep cycle batteries. No, don't ask!
Regards

I have an electrical background, the variables are huge. e.g. 25 amps discharge would yield a lower AH rate than a 5 amp discharge.

And the rating system appears to be based around a number of different methods

This is a good read.

Start reading from page 20

At 25 amps the rating decreases to 67% or its 5 amp rating

A bit more info I found:

RC=Reserve Capacity at 80? (27?)The reserve capacity is the time in minutes that a new, fully charged battery can be continuously discharged at 25 amperes and maintains at least 1.75 volts per cell (10.5 volts for a 12-volt battery).

Minutes discharged at 50, 25, 15, 8, and 5 AmperesMinutes discharged is the time in minutes that a new, fully charged battery will deliver at various currents and maintains at least 1.75 volts per cell. These are nominal or average ratings.

Ampere Hour Capacity at 20, 10, 5, 3 and 1 Hour RatesAmpere hour capacity is a unit of measure that is calculated by multiplying the current in amperes by the time in hours of discharge to 1.75 volts per cell. These are nominal or average ratings.

Examples
5 amperes for 20 hours (5×20) = 100 AH @ the 20-hour rate
10 amperes for 3 hours (10×3) = 30 AH @ the 3-hour rate
20 amperes for 1 hours (20×1) = 20 AH @ the 1-hour rate

Therefore, if you have am application that requires a draw of 15 amperes for 5 hours, you would need a 75 AH battery (@ the 5-hour rate).

Examples 5 amperes for 20 hours (5×20) = 100 AH @ the 20-hour rate
10 amperes for 3 hours (10×3) = 30 AH @ the 3-hour rate
20 amperes for 1 hours (20×1) = 20 AH @ the 1-hour rate
Ampere hour capacity is a unit of measure that is calculated by multiplying the current in amperes by the time in hours of discharge to 1.75 volts per cell. These are nominal or average ratings.

I just use a honda EU20

But...

* Have to constantly buy fuel for generator
* Have to carry & store the generator & the fuel
* Have to be there to monitor the battery performance
* Generator will not automatically start-up when your away fishing
* If your parked in a National Park you can't use the generator anyway
* If your parked in a shopping centre car-park you can't set-up the generator
* Batteries run down faster and much lower with a generator than with more efficient methods

Nudie,
Please forgive me, sorry I could not resist :-)

Maîneÿ . . .

point 3.....i dont monitor nothin...the ctek does that
point 4...i make sure i have enough petrol in it to keep it going most of the day charging batteries and keeping the fridge cold....the only thing i do monitor
point 5...the only time i go to a national park these days is on feral pest culls...and we can atke anything we like
point 6...why would i camp at marion shopping centre or cassurinna for that matter
point 7...cant be true
poit 1 & 2 iiithink of something a bit later......

* Have to be there to monitor the battery performance
"i dont monitor nothin...the ctek does that"
. . . So obviously the generator is left running :-)
using fuel, making some noise and creating dangerous gasses too, while the Ctek is putting NO charge into the battery because it's full while your not there to monitor it ?

* Generator will not automatically start-up when your away fishing
"i make sure i have enough petrol in it to keep it going most of the day charging batteries and keeping the fridge cold....the only thing i do monitor"
. . . See reply above :-)

* If your parked in a National Park you can't use the generator anyway
"the only time i go to a national park these days is on feral pest culls and we can atke anything we like"
. . . Not in WA and NT

* If your parked in a shopping centre car-park you can't set-up the generator
"why would i camp at marion shopping centre or cassurinna for that matter"
. . . True, why would you even want to go there in the first place ??

* Batteries run down faster and much lower with a generator than with more efficient methods
"cant be true"
. . . Yes it's absolutely positively true and it's even factual too :))

Nudie, will wait for replies to points 1 and 2 with some anticipation ha ha
you say you "have enough petrol in it to keep it going most of the day" you would use a lot of fuel (lots $$$) on a holiday of a month duration when bush camping.
However with a more efficient power supply systems that will cost the same or even less than a Honda EU20 initially and with no ongoing fuel or maintenance costs either you must save money and hassles too :-)

( yes, I realise all above is mentioned in good spirit )

Maîneÿ . . .

"I reckon its more like a SWL rating. The battery will actually deliver more than the 100AH but is rated such that it will deliver that much and then further drain will deteriorate the battery and eventually kill it prematurely."

- that's DEFINITELY not the way batteries are rated.

The amphours is the ABSOLUTE maximum you can get out of it. 50% is a SWL which will give a long battery life.

Mike, you're right I read up on it. The amphour rating is what the battery will deliver until it hits 10.5v and is basically dead.

Mainey - re the following (point 7)
* Batteries run down faster and much lower with a generator than with more efficient methods

What do you mean? That a battery will run down faster if charged by a generator than if charged by solar or mains power? That cant be right surely.

Bonz, Yes " Batteries run down faster and much lower with a generator than with more efficient methods " it is correct

Maîneÿ . . .

How can that be? What do you mean? That a battery will run down faster if charged by a generator than if charged by solar or mains power? That cant be right surely.

Surely Mainey the discharge rate is separate from the charging method. No electrical theory I have ever learned tells me any different.

Bonz,
A SÖLAR system will charge an Auxiliary battery system, and will also continue to power all the 12v accessories during the day, which is the high drain and heavy battery use time anyway.
This will ensure the Auxiliary battery system remains FULLY CHARGED at the end of each day, the Auxiliary battery system will then only have to power the 12v accessories during the night.

SÖLAR will start recharging the batteries again early next morning and again will run all the appliances during the day.

* This is a very boring & repetitive procedure that will occur daily

* Fortunately you won’t even have to be there to supervise it :-))

* A correctly specified SÖLAR system will power your 12v accessories and also charge the Auxiliary battery system.

* During the day, the 12v accessories are NØT drawing any 12v power from the Auxiliary battery system

* Only during the night, is the 12v Auxiliary battery system powering the 12v accessories

* The Aux battery system probably will not get below 12v in any 24 hour period, mine doesn't and it runs a fridge drawing 10 Amps, plus lighting etc.



A generator must be actually running to charge the aux battery system.

Most people run their generator from late afternoon to recharge their aux battery system that has been running the fridge during the day and also the previous night.
The battery has been drained all day in this situation which is the heavy draw time, the Aux battery will have drained down to <12v.

If your not there to "turn on" the generator and the battery runs down even lower it can and it will damage the battery.

That's just another reason so many Aux batteries last so long when charged by solar power.

Maîneÿ . . .

hey Smarty pants!
A generator and CTEK will charge an Auxiliary battery system, and will also continue to power all the 12v accessories during the day, which is the high drain and heavy battery use time anyway.
This will ensure the Auxiliary battery system remains FULLY CHARGED at the end of each day, the Auxiliary battery system will then only have to power the 12v accessories during the night.

A generator will also start recharging the batteries again early next morning and again will run all the appliances during the day.

* This is a very boring & repetitive procedure that will occur daily

* Fortunately I will be there to start it cos I need lots of beauty sleep, breakfast and I am the supervisor!

...I was thinking of investing in a solar system when i get the $$$$... just need to figure out how to claim it as a business expense...:))))

Richard well said, Just put it down as your prefered power source when working in remote areas like the local jetty.
I'm sure Honda and Ctek will cost more than a solar system of same output :-)

Maîneÿ . . .

Ahhh Mainey, never one to let facts confuse one of your 'theories'.
I can't believe that you haven't picked up at least some 12VDC knowledge in the last few years.



ed

Thylacine
( umm, extinct ? )

Please state exactly what you believe is incorrect

then state what you believe is the correct answer :-)

Maîneÿ . . .

I think the last time we communicated I explained how difficult/frustrating/seemingly pointless it was trying to educate you, and recommended some literature to do the job (the prescribed textbook for electrical trades in VIC at the time).
You've obviously not gone near this, so explain again why my job is to teach you?
This forum is (and has been for years) rife with misinformation in regards to 12VDC systems. Many have tried to rectify this only to all end leaving in discust at the end of it all. I *very* rarely post here for just such reason. Over the five plus years I've perused this forum I've seen many posts recommending circuits that are absolute fire-hazards, yet if said circuit is posted by a 'regular' the knowledge-level of anyone pointing out the danger involved is ignored and the poor fool abused.
I cannot understand why self-taught blokes with a basic understanding of Ohm's law will dispute an expert. "You're wrong" they'll cry, yet offer no factual information to back this up. If you explain why it is so they'll often dispute the explanation due to lack of understanding.
Personally, I don't offer advice on any subject unless I have a *thorough* understanding of it. It's easy to bandy around a few electrical terms and convince a novice that you know what you're on about. But it's neither ethical or in the interest of the forum.



ed

Thylacine,

Why not just answer the question I've asked of you ?

If you believe anything above is wrong, why not dissect it bit by bit and explain why you believe it is wrong, don't denigrate this forum just to cover your lack of ability to show the facts are indeed facts

Maîneÿ . . .

At $500 I'd add the solar panels aswell, did this include a regulator?' look for one that does a float charge if your going to have it permently attached.
The life time of panels are up to 10-20 years. This would allow you to keep your battries in optium conditon,
As others have mentioned as it gets a warmer ambient temperture the draw will be more,on your test did you have anything in the fridge.
Nothing worse then been out there and not having the fridge and lights working. I have ruined a battery by running it too flat and it was a huge pain as the battery then only ran half a day after a charge. Was another 4 days camping before I got a new one.
My 50L fridge lasted 3 day in a melbourne winter but get 1.5 in North Oz, Now I use a 100W solar panel and camp as long as the food and drink lasts.

Then open and close the fridge a few times and see the results.