Diesel heater v battery

As I have not had a Eberspacher Airtonic heater before I am trying to understand the in's & out's of the power it needs to run as designed, We have a 2007 Symbol which we brought in November, last week we ran the heater for 1 hour and it shut down due to loss of battery power, we went onto hook up and it ran O K for a few hours as we were cleaning our new to us van,, So since then I have got a plug in 12v voltmeter which I plug into the tv cigar light which I fitted in the T V box above the 3rd seat I use this as 12v power when needed, The 1st reading on plug in was 12.8,, Started the heater on a medium setting, watch the voltmeter the figures start to drop dramatic, 11.7 then 11.2 then 10.9 then 10.5,, as the heater starts to blow warm the figures start to rise, now the heater is running with proper warm air the voltmeter has settled down to 11.4,, ran the heater for 15 mins, then went for shut down of the heater, surprisingly to me the voltmeter readings dropped to 10.8 as the heater when through it's shut down phase, the voltmeter started to climb and finish at 12.4 when the heater turned off,,, So battery at 12.8 ran heater of 15 mins, now battery at 12.4, I don't know a lot about batteries and watts and amps, so is my battery no good, (needing a new one) or is it just the amount of power needed to run these heaters, I was not able to start the engine to see what the volts reading were with the split charger as the Leisure battery shuts off from the back of the van with the engine running, If I were to buy a new battery, How long with a fully charged battery could you use the heater, would you be able to wild camp for a few days or is this to much for the battery,  Thanks Guys if you got this far, I know I've gone on a bit, But We so like this van and want it to work for us, Hungry for INFO Please,, Jan&Bob

My initial guesses would be either that the battery is tired, or that there's a loose connection at at least one battery terminal, allowing the 12V supply to the whole van to drop under load.

I don't know which Eber' you have but, for example, the D2 manual says that at full power the unit uses 34W and at lowest power 8W.

Depending on initial battery voltage, that's something less then 3A at full power, and a little over half an amp at low power.

I wouldn't expect that to flatten a good battery in fifteen minutes.

First thing is to check and maybe clean the main hab battery terminal clamps, then check the supply cables to the Eber for good connections at both ends.
Finger tight and/or dirty/corroded is not good enough, they must be clean and tight.

Once you find the problem, if it was me, and I was relying on the battery to provide heating, I'd be looking at making Ah savings elsewhere to leave more available for the heater. First mod would be all LED lighting, as the fluorescents and halogens if still fitted will draw as much as the Eber or even more.
An LED TV and satellite box or DVD player will also use about the same or more as the heater.
If you had all three on at once, the heater would only run for around a third of the time that it would on its own.

EDIT: Forgot to mention that the manual says that the D2 uses around 100W, presumably for the diesel glow plug, at startup until the catalyst takes over. You need a good battery and good connections for that, as it could be around 8A for a short time.

We had a Duetto with this set-up. The high current consumption at start-up and shut-down is normal, it is caused by the glow pin being heated up for ignition and also for burning off any deposits at the end of use. We have managed a weekend away without any problems when we had the van. We had a 90 a/h battery fitted and that (a Varta LFD90) coped without any difficulty, although it must be said that the weather was not very cold.

Given the age of your van do you have the mains heating element fitted? Our Duetto was built in 2007 and it had both the diesel and electric capability in the D2.

To use a diesel heater and everything else (lights. TV etc), the bigger your battery(ies) the better. If your battery is original, I would be looking to change it, as it has probably lost a lot of capacity by now.

Put 'Eberspacher' in the search box at the top of the page and all will be come clearer.
This problem has been well aired in the past and you will get the gist of the problems with this form of heating.
frederic
(and carry a small fan heater etc for when on 230v )

meanchris wrote:My initial guesses would be either that the battery is tired, or that there's a loose connection at at least one battery terminal, allowing the 12V supply to the whole van to drop under load.

I don't know which Eber' you have but, for example, the D2 manual says that at full power the unit uses 34W and at lowest power 8W.

Depending on initial battery voltage, that's something less then 3A at full power, and a little over half an amp at low power.

I wouldn't expect that to flatten a good battery in fifteen minutes.

First thing is to check and maybe clean the main hab battery terminal clamps, then check the supply cables to the Eber for good connections at both ends.
Finger tight and/or dirty/corroded is not good enough, they must be clean and tight.

Once you find the problem, if it was me, and I was relying on the battery to provide heating, I'd be looking at making Ah savings elsewhere to leave more available for the heater. First mod would be all LED lighting, as the fluorescents and halogens if still fitted will draw as much as the Eber or even more.
An LED TV and satellite box or DVD player will also use about the same or more as the heater.
If you had all three on at once, the heater would only run for around a third of the time that it would on its own.

EDIT: Forgot to mention that the manual says that the D2 uses around 100W, presumably for the diesel glow plug, at startup until the catalyst takes over. You need a good battery and good connections for that, as it could be around 8A for a short time.

I started to remove the drivers seat today to do the checks on the terminals etc, But it was to cold to stand with the door open and getting to old for the cold,,and the two rear allen keys were solid so I have wd40 on them, Hope to loosen them by tomorrow, The heater will be the only one using power, as we don't do T V. I do not have the manuals for the van, But if I did, reading and understanding what I have read will be a problem and as you have said the D2 which I think I have uses around 100W,,,, I do not know what that means,, I can not seem to get my head around watts & Amps, I know the battery was replace in 2013 85Ah as there is a receipt for one in the paper work that came with the van, I know that  does not make it a good one, But thanks to the forum I have something to go on, On a new battery of 85Ah how long should a heater run for before battery loss and shut down,, I know " how long is a piece of string " but any figure? Thanks

Spospe wrote:We had a Duetto with this set-up. The high current consumption at start-up and shut-down is normal, it is caused by the glow pin being heated up for ignition and also for burning off any deposits at the end of use. We have managed a weekend away without any problems when we had the van. We had a 90 a/h battery fitted and that (a Varta LFD90) coped without any difficulty, although it must be said that the weather was not very cold.

Given the age of your van do you have the mains heating element fitted? Our Duetto was built in 2007 and it had both the diesel and electric capability in the D2.

To use a diesel heater and everything else (lights. TV etc), the bigger your battery(ies) the better. If your battery is original, I would be looking to change it, as it has probably lost a lot of capacity by now.Hi 

Hi can you tell me what you mean when you say,,,,,( do you have a mains heating element fitted ) The battery was replaced in 2013 with a 85Ah But I don't know if it's a good one or not,, showed 12.8 on the volt meter, but again I don't know what that means,, I am trying to get my head around watts & amps,, I think I be rubbish at fitting a solar panel,,

frederic wrote:Put 'Eberspacher' in the search box at the top of the page and all will be come clearer.
This problem has been well aired in the past and you will get the gist of the problems with this form of heating.
frederic
(and carry a small fan heater etc for when on 230v )

Took your advice,, there is so much to learn from other people,,many thanks
Bob

I would guess that, with a good 85Ah battery, fully charged to start with, and assuming cautious usage of other equipment like halogen lights, you might expect somewhere between 12-36 hours of heater, depending on what power settings it's on.

That's a pretty wide margin, as I wouldn't want you to take it as 'gospel', it depends on so many variables.

Maybe mojo, or Peter, or one of our many other capable battery experts would like to comment.

As for the technical terms, if you have no grounding in the physics of electricity, maybe the best way to explain is with an analogy, so...

V is for voltage, e.g. 12V - this is like electrical pressure, similar to the pressure in a water pipe.
A is for current in amperes, e.g. 5A - which is like water flow in a pipe.
W is for watts, e.g. 60W - which is a measure of work done and could be compared, at a stretch maybe, with the amount of work that water flowing over a water wheel or turbine is doing.
You might notice that 12(V) x 5(A) = 60(W), i.e. voltage x current = power, much like it does with a water wheel in my loose analogy. (This only works exactly under certain conditions, but will be reasonably accurate in the context of your 12V DC system)
Ah is what you might suspect, a current flowing for a time period, i.e. 1Ah would be 1A flowing for 1h(our), or 2A flowing for half an hour, (or even 3600A flowing for one second, not something that you want to be around where a 12V van battery is concerned, maybe a short circuit where someone suicidal decides to test a battery by placing a big spanner across the terminals). DO NOT EVER DO THIS. NOT EVER.
Ah (amp-hours) is a measure of transferred 'charge' so, effectively, an 100Ah battery could deliver 1A for 100 hours, or 10A for 10 hours.
It's not quite as simple as that, however, as it depends on the condition of the battery, and how far you're prepared to discharge it before it's damaged for a start.
If you've stuck with me this far though, you'll be getting the general idea.

Basically, a battery, or bank of batteries is an energy store which can flexibly deliver a lot of energy quickly, or a little energy over a long time.
When planning your installation capacity in Ah, you can basically decide how big the battery or batteries need to be by adding up the current drawn by all your equipment in A (amps) and then deciding how long you want the battery to be able to deliver that current for.
If you know how many amps your D2 heater, lights, water pump, flush pump, TV etc draw individually, you can work out how long you can use each device for before the battery requires recharging with some simple arithmetic.

Pedants and perfectionists, please feel free to rip my attempt at keeping it a simple explanation to shreds.

meanchris wrote:I would guess that, with a good 85Ah battery, fully charged to start with, and assuming cautious usage of other equipment like halogen lights, you might expect somewhere between 12-36 hours of heater, depending on what power settings it's on.

That's a pretty wide margin, as I wouldn't want you to take it as 'gospel', it depends on so many variables.

Maybe mojo, or Peter, or one of our many other capable battery experts would like to comment.

As for the technical terms, if you have no grounding in the physics of electricity, maybe the best way to explain is with an analogy, so...

V is for voltage, e.g. 12V - this is like electrical pressure, similar to the pressure in a water pipe.
A is for current in amperes, e.g. 5A - which is like water flow in a pipe.
W is for watts, e.g. 60W - which is a measure of work done and could be compared, at a stretch maybe, with the amount of work that water flowing over a water wheel or turbine is doing.
You might notice that 12(V) x 5(A) = 60(W), i.e. voltage x current = power, much like it does with a water wheel in my loose analogy. (This only works exactly under certain conditions, but will be reasonably accurate in the context of your 12V DC system)
Ah is what you might suspect, a current flowing for a time period, i.e. 1Ah would be 1A flowing for 1h(our), or 2A flowing for half an hour, (or even 3600A flowing for one second, not something that you want to be around where a 12V van battery is concerned, maybe a short circuit where someone suicidal decides to test a battery by placing a big spanner across the terminals). DO NOT EVER DO THIS. NOT EVER.
Ah (amp-hours) is a measure of transferred 'charge' so, effectively, an 100Ah battery could deliver 1A for 100 hours, or 10A for 10 hours.
It's not quite as simple as that, however, as it depends on the condition of the battery, and how far you're prepared to discharge it before it's damaged for a start.
If you've stuck with me this far though, you'll be getting the general idea.

Basically, a battery, or bank of batteries is an energy store which can flexibly deliver a lot of energy quickly, or a little energy over a long time.
When planning your installation capacity in Ah, you can basically decide how big the battery or batteries need to be by adding up the current drawn by all your equipment in A (amps) and then deciding how long you want the battery to be able to deliver that current for.
If you know how many amps your D2 heater, lights, water pump, flush pump, TV etc draw individually, you can work out how long you can use each device for before the battery requires recharging with some simple arithmetic.

Pedants and perfectionists, please feel free to rip my attempt at keeping it a simple explanation to shreds.

All good stuff Kim how about a simple explanation of Peukert's law for the next lesson.

Okay:

"Always assume that a (lead/acid) battery will - 1. give up before your rough calculation says it should and 2. Just when you need it the most."

bobbysong wrote:The 1st reading on plug in was 12.8,, Started the heater on a medium setting, watch the voltmeter the figures start to drop dramatic, 11.7 then 11.2 then 10.9 then 10.5

I had a Eberspacher D2 on our 2002 Symbol and I spent many hours watching the voltage when starting it, and reading the docs to try and understand what was going on.

bobbysong. you say "The 1st reading on plug in was 12.8,, Started the heater on a medium setting, watch the voltmeter the figures start to drop dramatic, 11.7 then 11.2 then 10.9 then 10.5,"

That is hard to understand and interpret as those voltages are far below what I would expect. The starting voltage of 12.8V is fine but the other voltages seem far too low.
When the battery has to supply the startup current the voltage will fall but I don't think a workable battery would drop that much.
I would expect the Eberspachers failsafe to trigger before 10.5V and it would refuse to start,  it would think your battery is not able to supply enough power for it to shutdown safely.

These units are quite small and get really hot. If I had any doubt I would get it examined by a specialist.

If your voltages are correct then your battery probably needs to be replaced but in order to avoid unnecessary expense, I would confirm the voltages by measuring the voltage with a multimeter (£10 Maplin)  on the battery (terminals) under the drivers seat. Easy access inside van, just push the drivers seat forward.

An un-serviceable battery can still show 12.7V open circuit. You only find its condition by putting it underload, when a good battery will not drop voltage much.

Update
Yachtsman use Eberspachers too and I have just seen on a sailing website that the D2 only cuts out if voltage drops to 10.5V for 20 seconds. I thought mine cutout long before 10.5V   and I thought a decent lead acid battery would supply 100W and keep its voltage above 12V
I still think that if your battery drops to 10.5V (battery terminals) on startup then it is probably kaput

I always started the engine first if I was going to use the heater as it lightens the load on the battery.

When I had my Topaz

meanchris wrote:I would guess that, with a good 85Ah battery, fully charged to start with, and assuming cautious usage of other equipment like halogen lights, you might expect somewhere between 12-36 hours of heater, depending on what power settings it's on.

That's a pretty wide margin, as I wouldn't want you to take it as 'gospel', it depends on so many variables.

Maybe mojo, or Peter, or one of our many other capable battery experts would like to comment.

As for the technical terms, if you have no grounding in the physics of electricity, maybe the best way to explain is with an analogy, so...

V is for voltage, e.g. 12V - this is like electrical pressure, similar to the pressure in a water pipe.
A is for current in amperes, e.g. 5A - which is like water flow in a pipe.
W is for watts, e.g. 60W - which is a measure of work done and could be compared, at a stretch maybe, with the amount of work that water flowing over a water wheel or turbine is doing.
You might notice that 12(V) x 5(A) = 60(W), i.e. voltage x current = power, much like it does with a water wheel in my loose analogy. (This only works exactly under certain conditions, but will be reasonably accurate in the context of your 12V DC system)
Ah is what you might suspect, a current flowing for a time period, i.e. 1Ah would be 1A flowing for 1h(our), or 2A flowing for half an hour, (or even 3600A flowing for one second, not something that you want to be around where a 12V van battery is concerned, maybe a short circuit where someone suicidal decides to test a battery by placing a big spanner across the terminals). DO NOT EVER DO THIS. NOT EVER.
Ah (amp-hours) is a measure of transferred 'charge' so, effectively, an 100Ah battery could deliver 1A for 100 hours, or 10A for 10 hours.
It's not quite as simple as that, however, as it depends on the condition of the battery, and how far you're prepared to discharge it before it's damaged for a start.
If you've stuck with me this far though, you'll be getting the general idea.

Basically, a battery, or bank of batteries is an energy store which can flexibly deliver a lot of energy quickly, or a little energy over a long time.
When planning your installation capacity in Ah, you can basically decide how big the battery or batteries need to be by adding up the current drawn by all your equipment in A (amps) and then deciding how long you want the battery to be able to deliver that current for.
If you know how many amps your D2 heater, lights, water pump, flush pump, TV etc draw individually, you can work out how long you can use each device for before the battery requires recharging with some simple arithmetic.

Pedants and perfectionists, please feel free to rip my attempt at keeping it a simple explanation to shreds.

Thanks, I think I kind of understood some of what you say, Thank you for taking the time to explain,,,,
I have been going through some problems others have had with their heaters on the forum, I think I am getting the knowledge required to operate the heater successfully, I do think my battery needs replacement, as what I have learned starting at 12.8 means nothing if it can not work the load put on it,, Today I have checked all terminals on battery & the D2, all seems solid, I had engine running before starting the heater,, The heater ran for much longer than before, But did quit working before I shut it down,, so new battery I think,, I am going through videos on youtube trying to lean more about battery amps watts,, 
Again many thanks,
Bob

Hi Bob,

I was hoping that you'd be able to check the battery connections before potentially spending the money on an unnecessary battery.

It does now sound as if the leisure battery has got sad and tired, so replacing it is probably the next step.
Let's hope things are improved after that.

njr001 wrote:From memory I think you will find having the unit serviced is about £300 or more. 

The manual suggests running the unit about once a month, I do try to remember to run it at about 3 monthly intervals. Given that your voltage readings dropped it's probably time for replacement if the connections appear OK. You might also consider fitting a Battery Master or equivalent.

Yes I do need a new battery, have done some testing, had engine running before and during start up of the D2, After shutting off engine, heater shut down after 45 mins on a some what high setting and shut down very quickly, waited 10 mins 7 tried to start it again this time without engine running, A no go,, I think the D2 is not at fault, I have a service receipt from last owner, service was done at DBS Swindon @ a cost of £191.54.

bobbysong wrote:

Spospe wrote:We had a Duetto with this set-up. The high current consumption at start-up and shut-down is normal, it is caused by the glow pin being heated up for ignition and also for burning off any deposits at the end of use. We have managed a weekend away without any problems when we had the van. We had a 90 a/h battery fitted and that (a Varta LFD90) coped without any difficulty, although it must be said that the weather was not very cold.

Given the age of your van do you have the mains heating element fitted? Our Duetto was built in 2007 and it had both the diesel and electric capability in the D2.

To use a diesel heater and everything else (lights. TV etc), the bigger your battery(ies) the better. If your battery is original, I would be looking to change it, as it has probably lost a lot of capacity by now.Hi 

Hi can you tell me what you mean when you say,,,,,( do you have a mains heating element fitted ) The battery was replaced in 2013 with a 85Ah But I don't know if it's a good one or not,, showed 12.8 on the volt meter, but again I don't know what that means,, I am trying to get my head around watts & amps,, I think I be rubbish at fitting a solar panel,,

From some time in 2007 Auto-Sleeper started fitting the Eber heaters with both diesel and mains electric capability. Our Duetto had the mains electric add-on unit, which consisted of another 'box' about the same size as the diesel unit and contained a fan and 900 watt heater element. The air trunking from the diesel unit ran through the electric section. The main difference was that the mains unit fan ran all the time at a constant speed and the heating element was switched on and off as required. Another quirk was that the mains section would not run on reversed polarity mains, if that was encountered, the unit automatically switched to diesel heating.

Spospe wrote:

bobbysong wrote:

Spospe wrote:We had a Duetto with this set-up. The high current consumption at start-up and shut-down is normal, it is caused by the glow pin being heated up for ignition and also for burning off any deposits at the end of use. We have managed a weekend away without any problems when we had the van. We had a 90 a/h battery fitted and that (a Varta LFD90) coped without any difficulty, although it must be said that the weather was not very cold.

Given the age of your van do you have the mains heating element fitted? Our Duetto was built in 2007 and it had both the diesel and electric capability in the D2.

To use a diesel heater and everything else (lights. TV etc), the bigger your battery(ies) the better. If your battery is original, I would be looking to change it, as it has probably lost a lot of capacity by now.Hi 

Hi can you tell me what you mean when you say,,,,,( do you have a mains heating element fitted ) The battery was replaced in 2013 with a 85Ah But I don't know if it's a good one or not,, showed 12.8 on the volt meter, but again I don't know what that means,, I am trying to get my head around watts & amps,, I think I be rubbish at fitting a solar panel,,

From some time in 2007 Auto-Sleeper started fitting the Eber heaters with both diesel and mains electric capability. Our Duetto had the mains electric add-on unit, which consisted of another 'box' about the same size as the diesel unit and contained a fan and 900 watt heater element. The air trunking from the diesel unit ran through the electric section. The main difference was that the mains unit fan ran all the time at a constant speed and the heating element was switched on and off as required. Another quirk was that the mains section would not run on reversed polarity mains, if that was encountered, the unit automatically switched to diesel heating.

Thank you for the info,, No I do not have the electric bit, It's just a D2 but what you have sounds good, I am going to buy a new battery and see if that's the problem,