Leisure Battery advice

[Steely Daniel]

Hi
I am new to Motorhome Fun and this is my first contribution. I have just acquired a used 2010 Swift Sundance 590 which I am extremely happy with.
However I just need a bit of advice regarding the leisure battery.
Basically, after driving the van for a decent trip of around 100 miles if I go into the van and turn on the power after a couple of daysI get warning sounds and lights that tell me that tell me that the leisure battery only has about 10 volts in it. I would presume thus indicates a duff battery but the battery has an indicator light which is showing green.
I suppose my question is how I know if the battery is charging and should I take any notice of the green indicator or are these unreliable?
No doubt this question has been asked a hundred times before, so if someone could tell me where to look I would be most grateful.

 

[pappajohn]

If its dropping to 10v after a couple of days its time for a new battery.

It does depend on your useage though.

Warm air heater fans will soon drain the battery if used for a while.
standard lights will also use a fair bit.
a modern tv may use 2 amps per hour......5hrs a day is 10 amps which could be 20% of your available power....times that by two days.....40%.....assumimg a single 110ah battery.

You need to regulate how much battery power you use and keep it to a minimum where possible.
turning off lights not immediately needed will extend the run time.

But it does sound like your battery has seen better days.

 

[Steely Daniel]

Thank you for your advice. As far as I am aware, nothing is on in the van and when go back into it a couple of days after a journey and turn on the power it alerts me that I only have 10 volts almost immediately.
What I don't get us that the battery had an indicator window which is showing green, which apparently indicates a healthy battery. Are these indicators unreliable?

 

[Deleted34567]

Charge your battery. Let the standing charge stabilise. Put an ampmeter in series and check if you have a drain with all switched off...... Could be something demanding current...... but
As others have stated, your battery may have seen better days.

But better you check first, as a new battery will drain too if there is a demand on it.

 

[mjltigger]

Thank you for your advice. As far as I am aware, nothing is on in the van and when go back into it a couple of days after a journey and turn on the power it alerts me that I only have 10 volts almost immediately.
What I don't get us that the battery had an indicator window which is showing green, which apparently indicates a healthy battery. Are these indicators unreliable?

The indicators aren't very reliable. They Help with battery condition but not charge in my experience.

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[JeanLuc]

Start by giving the battery a really good charge from 230V hook-up. A drive of 100 miles may not be sufficient to restore what you have used, particularly if you have a gel battery as these take longer to charge than wet lead-acid or AGM types.
It is good practice to do a hook-up charge before and after a trip - also periodically whist you are touring.

 

[Lenny HB]

If before you did your100 mile the battery was fairly flat a 100 miles is nowhere near long enough to fully charge it. Best to hook the van up to the mains for a couple of days to the battery fully charged then see how it goes.

Battery condition is always measured with the battery off load after letting it rest for at least half an hour.
Sounds like you got your 10 volt reading when the battery was under load so your battery is probably OK.

If you got two full days out of it after only a 100 mile drive to charge it, I would say you did very well.
If you only have a single battery depending on your load I would only expect 2/3 days out of a fully charged battery.

 

[Techno]

The charge indicator light is only connected across one of the 6 cells in the battery, it will not indicate if any of the other cells have failed BUT at 10 volts it would tell me that is the case.

EDIT plus one on what Lenny said

 

[pappajohn]

At 10v with no useage at all after two days means that battery is no more....its dead.

After 100 miles i wouldnt expect it to be much over 12v which is still too low.

if constantly allowed to drop to 10v the battery is already damaged beyond repair.

If the 10v is under load it must be quite a high load and would drag the battery even lower quite quickly.

 

[Steely Daniel]

Hi
Thanks to everyone for their helpful advice. I think that I was under the false impression that the habitation battery would basically charge up much in the same way that the a healthy car battery appears to essentially be fully charged after a fairly moderate journey in the vehicle. I presumed that the van alternator went on to charge the habitation battery once the vehicle battery was fully charged but I think that I am not right in believing this is the case.
I think I will take the battery out and charge on a separate charger and see how the voltage reads after doing this and connecting back to the van.

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[tonyidle]

Hi
Thanks to everyone for their helpful advice. I think that I was under the false impression that the habitation battery would basically charge up much in the same way that the a healthy car battery appears to essentially be fully charged after a fairly moderate journey in the vehicle. I presumed that the van alternator went on to charge the habitation battery once the vehicle battery was fully charged but I think that I am not right in believing this is the case.
I think I will take the battery out and charge on a separate charger and see how the voltage reads after doing this and connecting back to the van.

A healthy car battery is rarely discharged by more than a few percent. With an engine in good order it's asked for, say, 400 amps for less than 5 seconds to start the engine = less than 0.5 ampere-hours which will be replaced in a very short time by the alternator. On the other hand the leisure battery even if only discharged to 50% of capacity will ask for 50 Ah. Which will take a very long time to replenish.

 

[JeanLuc]

Hi
I presumed that the van alternator went on to charge the habitation battery once the vehicle battery was fully charged but I think that I am not right in believing this is the case.
I think I will take the battery out and charge on a separate charger and see how the voltage reads after doing this and connecting back to the van.

1. The alternator does charge both starter and leisure batteries. It just needs quite a long drive to recharge once you have discharged the leisure battery significantly. Tony's post above explains this.
2. I would not bother to remove the leisure battery to charge it. Just plug in to a 230v hook-up and the on-board charger will give the leisure battery a proper charge. I don't know anything about Swift vans, but all modern motorhomes have an intelligent, multi-stage charger.

 

[Lenny HB]

Hi
Thanks to everyone for their helpful advice. I think that I was under the false impression that the habitation battery would basically charge up much in the same way that the a healthy car battery appears to essentially be fully charged after a fairly moderate journey in the vehicle. I presumed that the van alternator went on to charge the habitation battery once the vehicle battery was fully charged but I think that I am not right in believing this is the case.
I think I will take the battery out and charge on a separate charger and see how the voltage reads after doing this and connecting back to the van.

I believe Swift only use a standard split charge relay to charge the leisure battery, with this type of arrangement they also tend to use fairly small cables which gives a volt drop which does nothing to help the charging. When you first start the engine the leisure battery will charge at about 10 - 15 amps (depends on the wiring) after ½ - 1 hour the terminal voltage across the battery will rise and the charge rate will drop to 4 or 5 amps maybe even lower, that's why even driving all day is unlikely to fully charge a flat leisure battery.
If you need the battery to be charged more efficiently while driving you could fit a battery master or similar product which will enable leisure battery to charge at a higher rate.

 

[SomeoneElse]

... I don't know anything about Swift vans, but all modern motorhomes have an intelligent, multi-stage charger.

That may be true of continental MH but is not true for the two British vans I have had, a 2010 Elddis Autoquest and a 2013 Bailey Approach.
Both those van had a 12V power supply unit which is not regulated but have a no load output of 13.8V. It makes a good float charger but takes longer to give a full charge. I wouldn't be surprised is Swift with the same history of Caravan manufacture as Elddis and Bailey didn't have the same. In which case an EHU charge will take a two or three days to get anywhere near a full charge and it will never take it up to absorption voltage. an external charge with a three stage charger of at least 5A would be better. The other danger of using this type of PSU to charge a leisure battery is the with a very low voltage from the battery the PSU may push a very high current towards the battery and blow the battery fuse. Elddis use a 15A and Bailey a 20A rated fuse on the battery line.

To give any real advise to the OP a voltage reading actually at the battery is needed, but dealers know that fitting a new battery corrects 99% of these sort of faults. They then only have to investigate the odd few cases that return, usually with the statement "never seen anything like this before"

 

[Lenny HB]

That may be true of continental MH but is not true for the two British vans I have had, a 2010 Elddis Autoquest and a 2013 Bailey Approach.
Both those van had a 12V power supply unit which is not regulated but have a no load output of 13.8V. It makes a good float charger but takes longer to give a full charge. I wouldn't be surprised is Swift with the same history of Caravan manufacture as Elddis and Bailey didn't have the same. In which case an EHU charge will take a two or three days to get anywhere near a

Blimey that's 1980's caravan technology, one would have thought they have moved on since then.
I thought Swift now fit Sargent unit which I thought we multi stage chargers.

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[JeanLuc]

I stand corrected - I too thought Swift fitted Sargent chargers. Seems a bit archaic not to fit a decent charger.
By the way, the item that boost charging whilst driving is a Battery-to-Battery charger, (B2B) not a Battery Master.

 

[SomeoneElse]

I thought Swift now fit Sargent unit which I thought we multi stage chargers.

I stand corrected - I too thought Swift fitted Sargent chargers. Seems a bit archaic not to fit a decent charger.

I have no knowledge of Swift, my suspicions were based on them having a history as a British caravan manufacturer. I rarely ( ie not in the last 12 months since fitting solar panels) used EHU. My solar controller is a proper three stage charger and works well.

The way Elddis/Bailey are wired ensures that the 12V appliances are never subject to more than 13.8V. I worried a little that the solar controller would subject them to 14.4V, which it does but they tolerate that voltage and still operate without problems.

 

[Lenny HB]

boost charging whilst driving is a Battery-to-Battery charger, (B2B) not a Battery Master.

I was being lazy couldn't remember which one did what & couldn't be bothered to look it up.

 

[Steely Daniel]

Thanks again to everyone for sharing their knowledge. I have definitely learned a few things about how the battery system works in a Motorhome.
Just to update, I have taken the battery out and connected a jump starter/ charger directly to the battery on its low powered setting. Before any charge, the battery read 12v on a multimeter, and after an hour on the charger it was up to 13.8v. All this suggests that the battery could be OK and I will put it back in the van tomorrow and see how it performs with a load on it.
My van has a recessed plastic compartment in the floor which will accommodate a second battery. So I have decided to add a second battery which seems a good upgrade, with the only downside being obviously the added weight. What has prompted me to add a second battery is the 15% discount which is available until tomorrow evening at Go Outdoors. This brought a fairly decent low profile 100ah leisure battery down from £80 to £68 which seemed pretty reasonable. Only condition is that you have one of their discount cards. I hope this may be if use if anyone else is thinking of changing their battery.

 

[DavidG58]

just be slightly wary of the second battery (new battery) being dragged down by the first (original) if it is still on the weak side, we have had exactly that, one good, one failed, nothing worked on 12V off charge

generally the advice seems to be to fit 2 new batteries at the same time

if funds allow that is what I would recommend you do, we did, although in fairness then found that one of them was fine

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[Lenny HB]

Thanks again to everyone for sharing their knowledge. I have definitely learned a few things about how the battery system works in a Motorhome.
Just to update, I have taken the battery out and connected a jump starter/ charger directly to the battery on its low powered setting. Before any charge, the battery read 12v on a multimeter, and after an hour on the charger it was up to 13.8v. All this suggests that the battery could be OK and I will put it back in the van tomorrow and see how it performs with a load on it.
My van has a recessed plastic compartment in the floor which will accommodate a second battery. So I have decided to add a second battery which seems a good upgrade, with the only downside being obviously the added weight. What has prompted me to add a second battery is the 15% discount which is available until tomorrow evening at Go Outdoors. This brought a fairly decent low profile 100ah leisure battery down from £80 to £68 which seemed pretty reasonable. Only condition is that you have one of their discount cards. I hope this may be if use if anyone else is thinking of changing their battery.

13.8v is not high enough to fully charge the battery needs to be taken up to 14.3 volts for a full charge.

As said if you are going to add a second battery you need to replace the existing one as well, especially as it doesn't sound in the best of health, also I wouldn't think 68 quid will buy a battery worth having, have a look at Banner & Exide leisure batteries a bit dearer buy it is not worth skimping on batteries.

 

[Steely Daniel]

Thanks again to everybody for all the useful advice.
Further bit of updating if anyone is still interested! Charged the battery out of the van fir about 36 hours at apparently about 1.5 amps, if you can believe the charger. Put it back in the van and turned on the power and it was reading about 13v on the control panel, so everything working OK.
However I think I can see what is causing the battery to drain. The van has an EC400 power control system. There is a display which can show van battery voltage, leisure battery voltage and charge/discharge amperage. Without any 12v item on in the back of the van it appears to be constantly draining at 0.7A. Not a lot, but enough to drain down the battery. I have the power turned off on the control panel and I tried removing each of the twenty 12v fuses one at a time to establish which circuit was draining the voltage. However none of the 20 circuits is the cause of the drain as it was still showing at 0.7A regardless of whichever fuse I removed.
I would be grateful if someone could tell me if I am totally missing the point here and there is a reason why there is this constant drain on the battery. Does the power control unit constantly consume power?

 

[pappajohn]

Does the power control unit constantly consume power?

Yes....unless the battery is isolated.
but i would expect maybe 70ma, not 700ma

700ma is almost 17 amps per 24hr day.

 

[hilldweller]

constantly draining at 0.7A. Not a lot

You are not tuned into leisure batteries yet, 0.7A is MASSIVE. You have to make every milli-amp count.

 

[Lenny HB]

700ma drain sounds a little high, our last Hymer was about 400-500ma with the panel switched on, our current van does not have an LCD panel and is only about 300ma, much less with the panel turned off.

I've just had a look at the EC400 on the Sargent site, it does have a multi stage charger an will do a better job of charging your battery than the the charger you were using, it will charge the battery up to 14.4 volts then reduce to a 13.6 volt maintenance charge.

When the charger is in standby will draw a small amount of current and
if you have a Truma Combi with an electric dump valve with take 35ma, with the panel off I would expect it to be less than 200ma, with the panel on that will draw some current as well, but 700ma seems a bit high.
I would give Sargent a ring they have a good name for being helpful.
Also if the stereo if wired to the leisure battery, it's back up memory will draw a small amount of current.

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[Bobby22]

I too have the Sargent EC400 and always depress the black shut off button when laid up. If my van doesn't move for 2 weeks I put it on hookup and set the 3 stage charger to do its job.

I only have 75ah battery and can get 3 nights and it has never shut down on me.
Manual suggests shut off when not in use.