# What can I expect from the alternator?



## cliffhanger (Jun 27, 2008)

Hi

When the van alternator is charging my leisure batteries I would expect at least 10amps initially when the leisures are at, say 40-50%, but I'm only getting just over 3 amps on long journeys dropping to as low as 1amp. Is this to be expected? Do I get much higher rates with flat leisures?

My charger is the Electroblock EBL99.

thanks

MAC 8)


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## 747 (Oct 2, 2009)

You should be getting 16 amps to the hab batteries and a 2 amp float to the van battery when on hookup. A similar rate should happen from the alternator (at least mine does).

You might have a dodgy alternator or your batteries might just be nearly 100% charged and the charging rate is dropping off (which is quite normal).

Use some of your battery power by switching lights on etc. for a few hours and then start your engine to see if the charging rate has gone up.

I think it is doubtful that your EBL is faulty as they either work or don't. There seems to be no inbetween.


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## Penquin (Oct 15, 2007)

I read a post on here somwhere which stated that the alternator is primarily governed by the vehicle battery; 

when that initially demands power the alternator gives it all it needs to bring it back to fully charged,

once that has been done the alternator gives much less power and that is why it takes so long to charge the leisure batteries.

That may be right or not - I do not know, but it does make sense and was used as part of the justification for fitting a special gizmo to ensure the leisure battery gets more charge to bring it up to full....

I cannot remember what the gizmo was (I know we haven't got one......) but am sure someone will tell me.....

I think it was a Sargent product but am happy to be corrected....

Dave


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## cliffhanger (Jun 27, 2008)

Thanks for the replies. 

I can be sure of the charge because I have a NASA battery monitor. It's definitely not giving anything like 16amps. The van is only a year old so I don't suspect the alternator. 3 amps is not enough to get the battery fully charged from 50%.

thanks

MAC 8)


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## safariboy (May 1, 2005)

The alternator output is controlled by the voltage at its terminals. When charging the van battery will be nearer the alternator and there will be some resistance in the wires on to the leisure battery. The result will be that the leisure battery will have a lower voltage at its terminals when the starter battery reaches full charge and causes the alternator battery to fall.

There are basically two ways of overcoming this. If you have very thick wires between the two batteries and short connections the difference will be small and so the charge will be more evenly spread between the two batteries.
There is a device available that effectively causes the alternator output to be controlled by the actual battery voltage. This will boost the battery charge. Unfortunately I do not have details but perhaps someone else does.

The essential problem is that the vehicle system is designed to keep the starter battery topped up when small charges have been removed. They are not really optimised for charging where a substantial charge has been drawn off.


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## WildThingsKev (Dec 29, 2009)

My 4 year old vehicle battery was on the way out with one duff cell so I changed it for a new one. I now find, as would be expected it seems, that the leisure battery charging from the alternator tails off quicker than it used to. I have not measured anything, but it just seems a bit different.

Kev


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## rayc (Jun 3, 2008)

I think the CBE system works as follows:

Alternator o/p above 13.3v charging to vehicle battery only.

Alternator o/p below 13.3v but above 12.0v then vehicle and leisure batteries are paralleled by the 'battery seperator'.

Battery seperator removes the parallel link if the 'engine + signal is removed when engine switched off or the alternator o/p is < 12.0v.



It therefore appears that the high 14v charge from the alternator only charges the engine battery.


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## safariboy (May 1, 2005)

This is not the device I was looking for I think. The CBE system is designed to keep the vehicle battery charged up when the leisure battery is connected to a mains charger.
I have found it:

http://www.sterling-power.com/products-altbatt-benefits.htm

I suggest contacting the firm if you are interested to make sure that I have got the right idea.


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## rayc (Jun 3, 2008)

safariboy said:


> This is not the device I was looking for I think. The CBE system is designed to keep the vehicle battery charged up when the leisure battery is connected to a mains charger.


And to charge the leisure battery when the vehicle is running.


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## cliffhanger (Jun 27, 2008)

Thanks

I have just plugged the van into mains with the 'leisures' on 51% and the NASA is showing 1amp being delivered. This can't be right, how can it be trickle charging when the batteries(180)are at 12.2v? Is there no way of adjusting the Electroblock?

I'm concerned because I'm going on a long trip and thought I had this covered 

MAC 8)


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## rayc (Jun 3, 2008)

cliffhanger said:


> Thanks
> 
> I have just plugged the van into mains with the 'leisures' on 51% and the NASA is showing 1amp being delivered. This can't be right, how can it be trickle charging when the batteries(180)are at 12.2v? Is there no way of adjusting the Electroblock?
> 
> ...


So to recap you are unhappy about the charge to the leisure batteries both when on EHU and from the alternator when the engine is running?

I guess what is needed is the charge rate graph for the Electroblock to understand what happens on EHU and also what the spec is for charging the leisure battery from the alternator.

Is the charger the "Additional Charger Schaudt battery charger type LAS ... with max. 18 A charging current"


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## Penquin (Oct 15, 2007)

Do you have a switch on the control box to select which battery receives the charge?

If so could it be set the wrong way?

i.e. if it is set to vehicle it will only trickle to leisure, if set to leisure then the vehicle will only receive a trickle......

otherwise it would be worth checking your leisure battery more carefully - how old is it, is there any chance that one cell is dead or dying? If so that would say "I am full" so the charger will not provide much charge....

PS The device I was looking for earlier is possibly Sterling or CTEK but I know it came up on here earlier this year.......

frustrating isn't it when you are sure there was something and CANNOT find it.... :roll: 

Dave


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## cliffhanger (Jun 27, 2008)

rayc said:


> cliffhanger said:
> 
> 
> > Thanks
> ...


Exactly. There should be more amps being delivered. I'll take a look at the Electroblock tomorrow. The batteries are new so it's not a cell problem.

With the NASA I expected a big charge when the batteries are 50% down. Of course it could be a NASA problem, but it's registering right on other 'draws' like laptops and t.v.s

MAC


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## 747 (Oct 2, 2009)

I was about to suggest a duff battery after thinking about it but if they are new, that is very doubtful.

What I would check though is the battery type switch on the EBL. If the batteries are not original, there is a slight chance that the switch on the EBL body is set incorrectly. It can be set to either GEL or LEAD/ACID. I forget the German signs but they are easily decipherable. It is important because they are 2 different charging regimes and could affect the battery life.

If the result is the same on hookup or alternator then it sounds like the EBL. If you think it is then you could speak to A & N Mobile Caravan Services. Their website is www.AandNcaravanservices.co.uk tel. no. 07803 072636

They do an exchange and/or repair of EBL's and their prices are cheaper than others (if you CAN find anyone else). They are based in North Wales if you are not too far away. Their website is very informative, I have dealt with them and they are very good.

Hope that helps.


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## rayc (Jun 3, 2008)

Any help?
http://www.surfandmedia.de/womo/schaudt_elektroblock_ebl99.pdf

In German but easy to translate with the help of google 

I realised there was a English copy in the MHF downloads section

http://www.motorhomefacts.com/modul...load&cid=22&min=10&orderby=titleA&show=10#cat


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## Sloany (May 15, 2010)

Hi, i fitted a Nasa monitor to one of my vans and got all sorts of odd readings. I discovered that i had not changed the default settings to match my battery bank. I cant remember what the default was but i had 4 no 180 ah batteries so had to enter 720 ah into the Nasa so it could set the correct parameters. Just a thought! 

Dave


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## organplayer (Jan 1, 2012)

*organplayer*

Have a Battery Mate fitted for when on EHp.Two 110watt solar panels when not onEHp and Sterling B 2 B 50amp charger for use when (1) travelling (2) when on site with no EHp. This Sterling is a super bit of kit and will keep leisure batteries topped up in cold evenings when using the Webasto heater and tv. Webasto saves using the LPG.


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## cliffhanger (Jun 27, 2008)

Thanks everyone

The charger is the the EBL 99K with max. 18 A charging current. It's new and I can't see it is incorrectly set, but will look.

MAC


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## cliffhanger (Jun 27, 2008)

Hi

Right. This problem is down to the wiring of the NASA(alright all those at the back quit sniggering).

When I wired it. I left the charger's negative wire on the original battery, which should go to the output of the shunt. Once attached properly the amperage input from EHU and the alternator is now correct.

I'm still thinking of a gizmo for charging the leisure faster by fooling the alternator into lower voltage detection.

What do you think of this:

http://www.sterling-power.com/products-altreg.htm

thanks to all again

MAC 8)


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## Penquin (Oct 15, 2007)

Thanks for that link - I knew I had seen it somewhere but couldn't find it - the Sterling site is not the easiest as it is aimed at the marine market - at least what I found was.....

http://www.motorhomefacts.com/ftopicp-1336776.html#1336776



Penquin said:


> PS The device I was looking for earlier is possibly Sterling or CTEK but I know it came up on here earlier this year.......


It looks a good piece of kit, but I wonder how easy it is to install......

they see it is easy, but then splitting the atom is easy once you know how - and I certainly would NOT find that easy....... :lol:

Dave


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## weldted (May 1, 2005)

*Battery charging*

Hi I have the Stirling battery to battery 50 amp charger, I find it a great piece of kit, it allows the engine battery to recover from starting the engine and then puts the charge to the leisure batteries causing the alternator to think the engine battery needs boosting. I also route the solar panels to the engine battery which in turn ensures the engine battery is fully charged when not on hook up any surplus going the the leisure batteries.


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## organplayer (Jan 1, 2012)

*organplayer*

Ditto to Weldted. The Sinclair B to B charger and the two 110watt solar panels mean we are pretty well independent of mains leccy.


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