# Battery Life



## bodgerco (May 23, 2005)

Since buying our new van I have been concerned at the lack of life from the batteries. We have two 130AH batteries and the van is controlled by a Schaudt Electroblok system which shows me the current state of the battery as a) current volts out b) current AH remaining in the leisure battery and c) current charge remaining as a percentage. 

I charged the batteries to full capacity from the mains and although I understand that using the Electroblok 3 stage charger does not give the maximum charge it reaches effectively about 80% which I am led to believe is what one might expect. At this fully charged state the AH is 207AH and the percentage is shown as 100% - ie it is fully charged. 

I then created a load by putting lights on and monitored the control panel to assess battery life. As the AH's were 'used up' so I could see a reduction of the percentage, AH remaining and the associated battery voltage. The relationship between the current AH and the percentage was linear as one would expect but the relationship to the volts was not, which again I would expect to be the case. 

Having left it in this state for a while at a remaining capacity of 124AH ( a reduction of 83AH) from fully charged the battery voltage has reduced to 12.1V. I know that the Schaudt cuts off the 12V at 11.9V and I am fairly confident that this will be reached by the time I have got to a reduction in AH of about 90 maximum. 

So out of a battery system with a total capacity of 260AH I get only 90AH - that doesn't sound great to me. 

The batteries have been tested - allegedly! 

While 90AH is enough for a few days I guess it still doesn't seem like a good deal. 

Does anyone have an explanation for this or a pointer to what may be wrong. 

As a 'supplementary' I am aware of the Stirling B2B chargers and that it might allow the battery to achieve greater that the current 80% fully charged level but I am not confident how this would be wired in conjuction with the Schaudt system. I read reports of having to actually disconnect the Schaudt but I need it to display all the other stuff so that doesn't sound a sensible move . 

Any advice please? 

Roy


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## teamsaga (Feb 26, 2006)

Hi Roy
cant offer any advice only to say I get similar results. I am on my third new battery in 6 months on a new van, its 110amp/hrs . after using 9/10 amp/hrs for 3 days my panel shows voltage down to 12 volts. this crashes to 10volts within hours with nothing switched on. the electrician at dealers says it is normal to only get 40/50 amp hrs from 110 battery and that a battery reading 12 volts is virtually flat. I guess I will have to instal a second battery.


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## Boff (May 10, 2005)

Hi Roy,

the device that shows you the AH and percentage values is a so-called "battery computer". As it is not possible to directly measure these quantities, the computer measures current and voltage and then based on these measurements calculates the remaining AH. Now with some of these battery computers it is necessary to set up certain parameters, like the nominal battery capacity, at the beginning. And maybe this setting is wrong in yours?

Regarding battery capacity in general: 
The nominal capacity of a leisure battery (NOT an engine starter battery!) is specified for 20 hours. Which means that a 130AH battery should hold for 20 hours if a current of 6.5Amps is drawn. If a higher current is drawn then the *total* available capacity will be lower (Some manufacturers also specify the capacity for 5 or 10 hours, which is significantly lower).

These figures of course require a healthy, fully charged battery to start with. And to avoid permanent battery degradation it should never be discharged more than about 50-60%.

However, if your "Elektroblock" cuts out already at 11.9V, then this is too early! Normally the cutout should not occur before 10.9V.

Best Regards,
Gerhard


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## bodgerco (May 23, 2005)

Thanks Boff

Yes initially the Nominal voltage WAS incorrecly setp by the dealer/manufacturer and the battery was eve worse but now it is correctly adjusted to 260AH.

When I said in my inital message that I anticipated it 'dropping out' at 11.9 this was based on memory. As a result of your input I rechecked the literature and at 11.9 it triggers the battery alarm but does NOT cut out until 10.5V. Later this morning I will continue my testing and report back on the point at which it actually stops producing 12V. What I am confident about is that at the level it was at last night it indicated a discharge of 40% from fully charged, so, I guess it could go another 10% before I can really be sure I have reached a level beyond which it should not go.

On a more general point though, the implication of your message was that a single 130AH battery SHOULD produce say 20hours @6.5A . Presumably though you are also saying that , in general, continuing to take power beyond 50% say, is not good for the battery so one must expect must less that this.


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## zulurita (May 9, 2005)

I have two 110 amp batteries and use Aires in France without electricity and have spent 5 days in one place and didn't have any problems with the battery power.

I tend to use sat TV for 3 hours a night, charge the laptop. I do have LED lights which saves power.

However I do have a 75W solar panel and consider this essential for topping up the batteries during the day if I am not driving.

On our recent trip the control panel never went below 12.5, the solar panel has its own indicator and that showed 12.6 or 12.7 at the end of tv viewing at 10 pm. The difference is due to where the displays are sited and voltage drop in wiring.


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## sallytrafic (Jan 17, 2006)

I would add that immediate and irretrievable damage mostly takes place if you discharge to below 10% of capacity. Generally keeping the battery above 50% capacity extends its life. A pragmatic approach might be to keep to the 50% 'rule' as far as possible but don't loose sleep over straying below 50% just be aware that you are shortening the battery life over what you might have achieved.


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## bodgerco (May 23, 2005)

Thaks you all for the information. I will continue my tests but I think I now understand the issues - except one.

I can see the value in trying to limit the discharge to 50% but of what?

Is this 50% of he nominal - in my case 260AH, or is it 50% of the maximum charge - in my case about 208AH?

My Electrblok tells me as a percentage of the 208AH. So I guess to get to the 50% is going to mean I have say 104AH to 'play with'. If on the other hand the 50% represents the nominal - ie 130AH then it means I only have (208-130) 68AH to play with. That represents quite a difference.

If it is related to the nominal then I can see the issue of Stirling B2B rasing it's head again.

Roy


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## Boff (May 10, 2005)

Hi Roy,

first of all, a 3-stage mains charger should be able to charge up your battery to 100% without any problems. (That is, if you give it enough time...)

So if the battery is - according to the charger switching to trickle charge stage - fully charged, and yet the battery computer does not show the full nominal capacity, then this can have two reasons: Either the battery computer is still not correctly set up. Or it has determined that your battery has already lost some of it's capacity due to age and/or other reasons. 

In any case, the 50% rule is a rule of thumb, and should be seen as such. A few percent more or less will not make a difference.

Best Regards,
Gerhard


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## bodgerco (May 23, 2005)

Thanks Boff - that is interesting.

I have just checked and the Nominal AH is setup correctly BUT after I charged of mains it reached a level of 208AH and 100%. Possibly I could have left it longer but I guess I assumed that having reached 100% that is as high as it would go.

So who has concluded that 208AH is 100%? If that is as much as the batteries will accept then , OK, the batteries might need changing, but a) the batteries are allegedly tested and also new, so this implies that the Electroblok has made that decision on the basis that it can't charge it any more. 

If the Electroblok could fully charge it to 260AH then , presumably this would still show 100% but the AH would read 260 rather than 208AH?


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## sallytrafic (Jan 17, 2006)

Apart from the most sophisticated battery management systems that continuously sample current in and current out, controllers haven't got a clue about how big your battery is. On the controllers of medium sophistication its a parameter that you have to enter, there is normally a menu item where you declare how big the battery is.


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## bodgerco (May 23, 2005)

Thanks ST.

Yes my Electroblok is of the latter type. There is a menu into which you can specify the 'Nominal' batter capacity and , in my case it is set up correctly.

Roy


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## sallytrafic (Jan 17, 2006)

bodgerco said:


> Thanks ST.
> 
> Yes my Electroblok is of the latter type. There is a menu into which you can specify the 'Nominal' batter capacity and , in my case it is set up correctly.
> 
> Roy


In that case Roy we need to delve into why it thinks that it is fully charged and/or why it gives the value of 207Ah and not 260Ah.

I first thought it was displaying useable Ah ie down to 10% but that would be 234Ah not 207Ah. Now 207Ah is around 80% as you said originally. Now as Boff has said and I agree a three stage charger should be able to get the battery to 100% so I wondered if the voltage disconnect is set up to trip at 20% charged (and hence your meter was displaying useable capacity) but you say its 10.5V and for me I equate that to zero charge.

You will note that the attached graph equates fully charged to >12.6V. The ">" allows for the surface charge. It would be good if anyone can throw any other light on this problem as similar problems are often reported on these forums.

You might like to read this thread where I report on a dying battery  >click here<


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## inkey-2008 (May 24, 2008)

hi

If you leave the battery after you have been drawing on it, it will recover some what and that is the real state of the battery as the charge in the plates equalise out the same as it does when on a float or equalising charge.

At Maplins you can get a clamp meter that shows the the voltage and amp draw on a cable. Also check the voltage at the battery with a multimeter across the terminals,this gives a more accurate state of the battery

Another check is to charge the battery and then disconnect it and see how long it will hold a full charge, if it drops from a full charge after a day then you may have a cell down.

Have you checked the water levels in the cells if you can get at them they may be low.

Andy


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## Andysam (May 10, 2005)

To answer a couple of you queries- yes the Sterling charger will put more charge in, It works by charging at a higher voltage than ordinary chargers inducing "gassing" which allows a higher charge. Using this method even "maintenance free" batteries will need topping up every now and again. Ordinary chargers charge to about 80% to prevent gassing hence the "maintenance free" batts. Ordinary batteries are best drained to 50% of capacity. The more expensive batts like elecsol etc are deep cycle batts which can be safely discharged to 30 or even 20% of capacity. These cost about 1/3 - 1/2 again more than a standard wet battery. Without changing your charger or batts I can't see that there's much you can do without (potentially) damaging your batts.

I run two 110aH deep cycle batts but we are heavy users of batts and wildcamp most of the time and move every 3rd morning at the most anyway thus recharging. I would recommend a decent solar panel to replace 1/4 to 1/2 of what you use daily extending your on site time to an extra day every 5.

HTH


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## bodgerco (May 23, 2005)

Well the discharge test is complete with the - somewhat predictable - results that it dropped from the 'full' charge of 208 down to 104AH ( 50%) at which point it had reached 11.9V and at that point I concluded there was no value in continuing although for some reason my Electroblok did not raise an alarm at 11.9V as the book says - anyway thats a different matter. 

Back to ST. Yes I can only see the following reasons why it doesn't charge to 100%. 

1. My battery(s) is duff. It has been tested but you do start to wonder to what extent though. 

2. The Electroblok is itself faulty. 

3. The Electroblok charger is not as good as I thought - the booklet says it is a three state charger so I assumed that would define it completely. I will talk to a couple of other users of this same van with the same Electroblok system to get their input. 

4. I didn't leave it on mains charge for long enough to reach full charge. I have reconnected to the mains and I will leave it without discharge and monitor that. That is the easy thing to do.


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## bodgerco (May 23, 2005)

AndySam 

That is a really useful input. The fact that the Elecsols allow discharge down to say 20% sounds like a good deal to me. 

You say that most chargers only charge to 80% so that may apply to the Electroblok despite it being a 'three stage charger'. 

Do you have an Electroblok? If so did it create difficulties installing the Sterling with the Electroblok? 

Roy


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## Andysam (May 10, 2005)

For near 100% charging, a 4 (or more) stage charger is needed.


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## bodgerco (May 23, 2005)

Thank you AndySam 

I wonder if the difference between you and Boff is simply TIME 

Boff says 
------------ 
first of all, a 3-stage mains charger should be able to charge up your battery to 100% without any problems. (That is, if you give it enough time...) 
----------- 

You are saying 4 stage is required. 

Is it 'simply' a question of time. Would a 3 stage - like the Electroblok - eventually get to 100% if one left it on mains for long enough? How long? 

Roy


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## sallytrafic (Jan 17, 2006)

Time is certainly important.

The chemical reaction of charge and discharge takes place most easily at the surface of the plates it takes time for the charge to migrate to deeper parts of the plate to give 100% charge. 

My understanding of 3 stage v 4 stage charging is that in the 4 stage charge a new first stage is introduced the following three stages are similar therefore I reckon that a 3 stage charger will produce a 100% charge. The 4 stage charger will do it quicker thanks to the first stage.


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## 101405 (Oct 15, 2006)

Something really wrong here, I have a small hymer camp with 2 leisure batts. they never ever go out of the green (hymer volt meter) its stored overwinter mostly .never go flat. away 3/4 months summer mostly wildcamping may be two or 3 campsites never go out the green , starter battery I can go anytime to the vehicle after not visiting it for months !starts first time. simple Fiat/ hymer electrics ,but what we dont have is tv's , microwaves , just a pc to play the odd dvd (for poor weather times in France) In summer months its light till 11-ish , A good quality battery should last upto 6/7yrs .just changed the battery on my Mitsubishi 4x4 , 7yrs old.


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## Andysam (May 10, 2005)

Sorry bodgerco- I think our posts crossed.

No I don't have a Electroblok but looked into and researched the Sterlings comprehensively. Sterling freely document the fitting instructions on their site and recommend removing other chargers from the charging circuit. (You can just remove the alternator / EHU input and run the Electroblok from the Sterling).

3 stage chargers are discussed in depth on the sbmcc forums. The respected conclusion is that a 3 stage will not fully charge a battery- it's not designed to. As I said earlier a 4 stage will gas (slightly "boil"!) the batteries allowing a full charge. Obviously the batts must be vented outside and checked regularly for electrolyte level.

I decided a 3 stage (Zig) was sufficient for my needs, but if i wanted to stay somewhere (static) for more then 2 nights I would be upgrading to a Sterling.


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## Andysam (May 10, 2005)

silversurfa said:


> A good quality battery should last upto 6/7yrs .just changed the battery on my Mitsubishi 4x4 , 7yrs old.


True enough, but a car battery cannot be compared to a leisure battery- the composition is completely different. Elecsols will last that long with CARE!


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## bodgerco (May 23, 2005)

OK I terminated my test and I can see that overnight on mains the batteries have recharged to 100% which in my case is still 208AH although it is interesting that the Electroblok shows '208AH?' I am not sure what the '?' signifies but I am leaving it on charge to see if that increases. 

But moving on I would like to ask another supplementary question. 

On our van, as I explained before, we have 260AH (2x130AH) charged from an Electroblok DT220 and it appears to be the case that it will only charge the battery to 80% because it is a 3 state charger and , perhaps, left a little longer on charge might lift that a bit, but I have spoken to a friend with the identical van - same model, same year, same electroblok BUT 210AH ( 2x105aH) batteries and his full charge appears to be much closer to the nominal and perhaps as high as 95%. 

This leads me to ask what the charger does differently , if anything, to charge a 260AH battery to that of a 210AH battery?. The fact that on the setup menu I have to specify the nominal level suggests that it needs to know this information for some reason - unless it is just to indicate the level of discharge during use, but since it never actually achieves 100% charge anyway this seems pointless. 

The other thing nagging in my mind is an 'off the cuff' comment made by the dealer in respect of another friend. 

Same model, same electroblok etc. He ordered his van with 260AH but it was delivered with 220AH (2x110) and when he complained the answer from the factory was that the electroblok charger was not compatible with a 260AH battery. He accepted the answer but in view of the fact that ours was fitted with 260AH only weeks before suggested something odd to me. 

I guess that there are possibly two explanations; first is that the factory/dealer are simply trying to hide an error or their part, but the second is that for some reason this Electroblok simply isn't 'man enough' to charge a 260AH battery adequately. 

Any suggestions as to what the explanation might be? 

Roy


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## Boff (May 10, 2005)

Hi!

@Andysam:

To my knowledge a 3-stage charger does the following: First it starts to charge with a constant current (Stage 1, I-phase), until the battery has reached a certain cutoff voltage, usually (for wet batteries at 20 degrees C) 14.4V. During this phase 1 the battery will be charged up to about 80%. Then (Stage 2, U0-phase) it maintains this constant voltage, while the current gradually reduces as the battery approaches 100% charge. Finally, when 100% charge is reached, the charger reduces the voltage to about 13.8V (Stage 3, U-phase) to maintain the full charge.

4-stage chargers have, to my knowledge, an additional phase with reduced current at the begin of the charge cycle, which is however only applied if the battery charge is very low.

@bodgerco:

It could indeed be a matter of time:

It is not that much the number of stages that distinguishes a cheap charger from a good one, but the method to determine the moment to switch over from stage 2 to stage 3. In cheap chargers this is simply a timer, which switches over after e.g. two hours. Good chargers however constantly monitor charging current during stage 2. In the begin of stage 2 the current drops rather rapidly, and then gradually approaches a constant value. And the good charger will not switch over to stage 3 before this constant value is reached.



bodgerco said:


> This leads me to ask what the charger does differently , if anything, to charge a 260AH battery to that of a 210AH battery?.


So, if the charger is of the cheap type, and the battery is too large for it, it will indeed switch over to stage 3 before 100% charge is reached. In stage 3, which is basically a trickle charge mode, it takes very, very long to reach 100% charge.



bodgerco said:


> but the second is that for some reason this Electroblok simply isn't 'man enough' to charge a 260AH battery adequately.


See my comment above. This could perhaps be true. I don't know to which category the Schaudt Elektroblock belongs, but Sterling (and the competitors like Votronic or Mastervolt) definitely are "good".

But before doing anything else you might want to check your battery label and find out what the nominal capacity actually is. Maybe you have indeed only 2x105Ah?

And, if you are looking at the battery, then find out whether it is a wet battery (has caps to refill demineralised water) or a gel battery. Because if you are going to buy a new charger then at least for a gel battery this should be a model with temperature compensation. (Does no harm for wet batteries, either.)

Best Regards,
Gerhard


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## Andysam (May 10, 2005)

Boff,

I disagree that 3 stage will ever fully charge a battery. The 4th (or more) stage (although not at the end) charges at 13.8v or above which causes gassing. This de-sulphurises the battery plates allowing more electrolyte to come into contact with the plates hence the higher capacity. As a 3 stage or less charger does not do this how can more charge be achieved?

Bodgerco,

Have you physically checked that the batts are in fact 130aH as Boff suggests? When I had a dealer supplied van I got nothing but "statements of fact which were significantly less than the truth"!


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## bodgerco (May 23, 2005)

I have just checked the installed batteries and I CAN confirm that they are both 130AH batteries according to the label. 

I have now spoken to two other users of this system - same van, same electroblok etc and I must first correct something from an earlier post 

It appears that both the others have 220AH whereas I have 260AH. In both their cases they are charged to 192AH representing 88% ish. I am only reaching 80%. My conclusion has to be simply that the Electroblok hasn't got sufficient 'something' to charge a 260AH battery. 

Indeed they are charged to 192AH and if we assume that they can use it to 50% = 110AH then they have a usable 82AH. 

I have a fully charged 208AH with a 50% level of 130AH leaving only 78AH usable. 

So bigger batteries but less charge available on site - seems daft. 

Roy


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## Boff (May 10, 2005)

Hi Roy!



bodgerco said:


> It appears that both the others have 220AH whereas I have 260AH. In both their cases they are charged to 192AH representing 88% ish. I am only reaching 80%. My conclusion has to be simply that the Electroblok hasn't got sufficient 'something' to charge a 260AH battery.


Could you give me the model number of your "Elektroblock". I have meanwhile found a website with documentation about them (German only...), so I could give you more info if I knew the model.

I would especially need to know if there is an "S" at the end of the model no. or not.

Best Regards,
Gerhard


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## bodgerco (May 23, 2005)

Boff 

That is very kind of you. 

I did look at the Schaudt web site but I couldn't see anything on our model which is : 

ELB 220 - 2 

That is the only number I can see and there is NOT an S. 

I have an English version of a non technical user handbook and it claims that the system can be setup for batteries up to batteries from 90 to 495AH ( some hope of that)! 

Roy


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## Boff (May 10, 2005)

Hi Roy!

seems I have found the "problem":

The battery capacity display on the control panel only shows you the *useable* capacity of the battery, not the total capacity! The system assumes that 80% of the nominal capacity, which is the value you enter, is actually useable.

So it seems that everything is OK. 

Best Regards,
Gerhard


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## bodgerco (May 23, 2005)

Boff 

I have also just re-read the English User Manual and you are correct. Some of the subtlety was lost in the translation I suspect but I get it now. 

Thank you very much indeed. 

Roy


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