Leisure battery danger level
We're new to caravanning and have a Swift, fitted with a 'Sargent EC' power control panel. The manual for this states:
"Note: Do not over discharge the battery. One of the most common causes of battery failure is when the battery is discharged below the recommended level of approximately 10v. Discharging a battery below this figure can cause permanent damage to one or more of the cells within the battery."
... and yet there are any number of websites, online discussions and charts that say the danger level for a battery is somewhere between 11.3v and 12.0v.
Is the manual wrong?
Also, do plug in volt metres like the one in the photo work accurately for leisure batteries?
Thanks
Mike
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Check this out: https://www.thebatteryshop.co.uk/car-battery-voltage-guide-34-w.asp
Don’t be alarmed if your voltmeter reads 14+ volts, just means the battery is on charge.
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I was under the impression the battery voltage should not drop below 12.0 volts but really a battery is potentially flat around 12.3.
At these levels the battery will easily recharge,continuous discharge could cause sulphation to the plates at around the voltage given in your manual.
I would only use the USB battery meter as an rough indication,for more accurate readings you should have a digital multimeter which will have an extra decimal point.
There is a difference in battery measurement between 12.60 (which could be 12.59 rounded up )and 12.69
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Battery at 10v doesn’t always mean the end. Weinsberg forgot to include a relay in the 12v supply to my fridge, so I had a couple of deep discharges before the penny dropped. Didn’t have enough volts to operate the central locking. Luckily the combination of a relatively new battery and quick recharge saved it. Three+ years in and the battery is still holding full charge.
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OP. If you go into 'My Profile' you can give yourself a nice screenname!
Re your battery question; it really is quite simple: anything over 12.7v battery is fine; below that the battery is at various states of needing charging and at 12v it is pretty flat. At 10v I doubt if it would even allow a light to be turned on (ie really flat!). A battery should be kept pretty well at full charge all the time. In winter I remove mine and store it in my garage checking the reading every couple of weeks using a multi meter and putting on charge if necessary. So in summery any reading below 12.6v and I would put my battery on charge.
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I believe the Sargent unit is a so called “smart” charger which means that on EHU the battery will be taken off-line and charged at up to 14.4 volts assuming you have a sealed battery. A standard charger floats at 13.8 volts - not enough to fully charge a discharged battery but not too much to damage it or the “12 volt” system.
Frankly, 10 volts and it’s as dead as a dodo and unlikely to recover. I would consider 12.3 volts to be the lowest to avoid the risk of reduced battery life.
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A point about Digital Meters if I may
! Like all bits of 'kit' meters should be used with care & handled similarly.
To be absolutely sure of their accuracy they should be checked & calibrated annually BUT they will give good service over many years without such expensive work only if they are treated with that care !!
Older style analogue meters need even more care & gentle handling.
I have an analogue multimeter which never leaves my premises, but is treated with kid gloves and is used purely to check on the digital meters at regular times.
If digital meters are mis-used they can be inaccurate to four places of decimals !!
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Thanks to all for the helpful replies - we clearly have much still to learn!
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Mike - that's better than a screenname! Don't worry we all started sometime and you will get on top of this caravanning thing quickly. If you have not yet been away in your caravan it is useful to go local site for a few days using everything in the caravan. If you forget something you would not be too far from home. Check lists for hitching up etc are in the Club handbook. There are always many willing hands on site, and on this forum, to get help from and most, if not all, are only to willing to help.
. Most important is not to forget bottle opener and sense of humour!0 -
My take on this:
Our lead acid batteries age more if not kept fully charged, even more the deeper from fully charged they are and the longer they stay partly discharged.
So a rule of thumb is try and avoid them not being discharged or left there long, both the depth and duration getting progressively more damaging.
BIt of an issue, as using them so discharging them comes along with why we need them, but understanding the issue helps gets the best life from them.
Now differing technologies of build, the structure and materials [lead alloying], significantly alter how individual battery types cope with these damaging discharge issues, all battery types are far from equal.
Therefore, no one is going to be able to put a marker down about a certain level of voltage causing damage, its impact varies so much with type, but the ground rules always apply, the greater the depth of discharge and the longer there, harms all.
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I discovered soon after getting into caravanning a couple of years ago the leisure battery quickly went flat when in storage. A bit of messing about with a multi meter and discovered the control box at the entrance to the van was permanently live, something to do with it being ready to receive signals from a remote.
Pull the fuse for the battery out and it stops the drain.
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Not always practical if you have a tracker / alarm, as the back up batteries on our old Bailey only operated for a few days and needed to top up from the Leisure battery. However, even with that drain I only needed to swap the battery over every 6 / 8 weeks, by which time it had discharged to 12.5 / 12.4 volts. What do you mean by quickly went flat? I would have thought the drain from a panel on standby for a remote input would have been minimal.
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A tip that I have mentioned before, is that we are lucky enough to store the caravan at home so always have it 'hooked up'. The power is on a timer, (unless overridden) and so the battery gets a two hour top up on a daily basis. I've done this for a few years without any apparent problem and always have a battery charged at about 12.8 volts.
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1. Get solar panel(s) - as much as will fit.
2. Swap to Lithium battery
3. Say goodbye to electrical energy problems.
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All the Autosleepers motorhomes that we have been looking at now have Lithium batteries as standard. Perhaps this is the future.
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Couldn't tell you the make of our caravan battery but we purchased a new caravan last year and a new battery was obtained at the same time. Unfortunately due to covid and lockdowns we only managed to use it for just over two weeks before putting it into storage hoping to use it again before the winter set in. Unfortunately we had another lockdown and were unable to get to our storage area except to drain the water out and to be honest forgot to remove the battery. The result was that when we eventually managed to get back to the caravan the battery was well and truly flat and I mean flat. The battery was removed and taken home where I have several smart chargers and two old analogue ones. At first the smart chargers would do absolutely nothing as with there being no voltage there was no reference for the smart chargers to pick up so it was put on an old 4amp analogue one which immediately fired up and left on charge for 24hrs before being switched over one of the smart chargers but this again would not fire up so it was put back on in parallel with the analogue one and left for three days before removing the older charger and leaving it to the smart one for a further two weeks. By this time the battery green fully charged indicator was back. We, tbh, have only had the caravan out once since then but we have a mover and have had no problems with it and even though that was six weeks ago the voltage indicator still showed 12.7v when we checked it this week so hopefully we have managed to save it.
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Whilst not to be recommended, I have managed to recover a couple of E-Bike batteries that had gone completely flat. So much so that, again, the charger wouldn't recognise the battery. I managed to fool it into accepting the charge by connecting the charger to the output terminals to put enough into the battery to enable it to charge normally. Moral to these tales - check your voltage periodically.
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My battery must be around 10 years old by now. My battery analyser suggests it has 90% capacity still - Only needed for the mover and for short stops, otherwise EHU and my caravan has a fixed 13.8v SMPSU.
In my opinion, at 10v a battery has suffered serious damage, but if it has not been left too long at that voltage, most of the capacity will be recoverable if put on charge quickly.
I certainly would be worried if I let any battery fall below 12.0 or even 12.3v.
In the past, I have left batteries year round on 13.8v via ECU at home in my drive and batteries have been dead after a couple of years of that treatment. Instead, now I disconnect the battery and reconnect every couple of months for 24 hours or so. After and before a trip, they get connected for 48 hours. Very occasionally, I put the battery on one of my Smart chargers.
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