First night away without hook-up for some time. Leisure battery showing 13.5V when we pitched up, in the morning showing 12.2V. Battery is 180Ah. Just used lights, water pump, router, and presumably some heater fan in the night. Is this normal?
Is my leisure battery ok?
- Thread starter acropolis22
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- Dec 24, 2014
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Sounds pretty normal to me from your generalised usage info and I wouldn't be concerned if I was driving today or having EHU later.
As an aside.....
Presumably you don't have solar?
The drain will be greater with filament lamps than if you have LED's.
The fridge/heating control panel will use some power but fairly minimal.
As an aside.....
Presumably you don't have solar?
The drain will be greater with filament lamps than if you have LED's.
The fridge/heating control panel will use some power but fairly minimal.
Its difficult to get an accurate reading from a leisure battery unless it has been disconnected and allowed to rest for a few hours before taking the reading. Obtaining an accurate reading whilst there is a load on the battery is even harder and almost impossible IMO. When I tested my leisure batteries a couple of weeks ago I had them down to 12.25V with a load on them. When the load was removed they recovered to 12.57 after 2 hours. I suspect you may well be OK as your taking a reading before your solar (? you have solar ? if not, get some, loads of it) replenishes your battery. If you ran your heater during the night, the likelihood is the fan which will be electric is where your biggest draw will be from and you need to keep an eye on that.
You don't say what type of battery you have and if its lead acid your taking 40% of its capacity out each night if you repeat this process in the same way. Your battery life will be determined by the number of cycles and depth of discharge it is rated at! i.e. 250 cycles @50% D.O.D.
You don't say what type of battery you have and if its lead acid your taking 40% of its capacity out each night if you repeat this process in the same way. Your battery life will be determined by the number of cycles and depth of discharge it is rated at! i.e. 250 cycles @50% D.O.D.
OP
OP
Thanks for your answers people. To clarify, the battery is AGM, and yes, we have solar. In fact the voltage has risen back to 12.7V now the sun is up.
That will be the reading from your solar regulator and not the actual battery state.
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OP
OP
Oh! So how do I know what is happening with the battery?
Terry
LIFE MEMBER
Hi if you have a 180 amp hr battery that means to take it down to 12.2 you have used around 80 amps overnight. That's a lot, even with blow air heating.
It could well be on its way out. To check fully charge when home, disconnect it from your van/ solar then check a couple of hours later then next morning,compare reading's
Or While it is off the van take it to a motor spares shopthey will have a tester that should tell you good or bad.
It could well be on its way out. To check fully charge when home, disconnect it from your van/ solar then check a couple of hours later then next morning,compare reading's
Or While it is off the van take it to a motor spares shop
they will have a tester that should tell you good or bad.
pappajohn
LIFE MEMBER
The only real way to check a leisure battery is by a controlled discharge.
IE... A known load applied over a period of time.
Garages/motoring shops will use a form of drop tester, applying a high load for a few seconds, which will probably show a positive result even if the battery is failing.
IE... A known load applied over a period of time.
Garages/motoring shops will use a form of drop tester, applying a high load for a few seconds, which will probably show a positive result even if the battery is failing.
Many members fit a battery monitor which more or less shows with reasonable accuracy the state of the battery. This would be the simplest way to know what your battery state is.
Here is an example of a reasonably priced good battery monitor. https://www.nasamarine.com/product/bm-1-bluetooth/
Alternatively, you could do the math yourself to work out what amps are being taken out of the battery. https://www.rpc.com.au/information/faq/system-design/estimate-demands.html
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With respect ! That's not quite right Terry. Just because this battery has been taken down to 12.2 Volts does not mean it could be on its way out. This battery was measured whilst still connected and almost certainly has some sort of a load on it meaning its true state was unknown and would have certainly been higher if disconnected and rested. Also, a Battery test done by a local garage or Halfords is useless as a leisure battery test as the test only takes a measurement over a very short time and a knickered Leisure battery would probably pass this type of test. A different type of test needs to be undertaken for a leisure battery so the remaining capacity can be calculated.Hi if you have a 180 amp hr battery that means to take it down to 12.2 you have used around 80 amps overnight. That's a lot, even with blow air heating.
It could well be on its way out. To check fully charge when home, disconnect it from your van/ solar then check a couple of hours later then next morning,compare reading's
Or While it is off the van take it to a motor spares shop
acropolis22 I certainly wouldn’t be worried about your battery if were mine as long as you can recharge within a reasonable time.
we have two 95 ah agm batteries with two 90 W solar panels and three weeks ago went up to Scotland we went six days without hook up and not moved for two days on one occasion and batteries were fine we could have probably gone for much longer with driving each day and sunshine. Our batteries are three years old and still holding charge well
and that was with using tv for four or five hours.
we have two 95 ah agm batteries with two 90 W solar panels and three weeks ago went up to Scotland we went six days without hook up and not moved for two days on one occasion and batteries were fine we could have probably gone for much longer with driving each day and sunshine. Our batteries are three years old and still holding charge well
and that was with using tv for four or five hours.
Terry
LIFE MEMBER
While I agree with some of what you say if the battery was fully charged ( we don't know if it was)assuming it was then 80 odd amps overnight is a big drop
plus as you say 12.2 still under load ,? I would think the solar would have kicked in so should have been A higher reading.I agree with PPJ
The local car shop I used had a posh tester that cost £500 plus and as yet I have always found Thier
answers to prove correct
IE battery good / bad 
Edit I am not suggesting that the battery is kna....erd just that it needs testing to find out if it is
Why are you assuming that?
What with loads still connected and solar
we have no idea. Perhaps it's time for the knowledge bot to appear
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Terry
LIFE MEMBER
I am afraid we can only assume as OP has not given enough information. Hence my suggestion to get it tested IF it has used 80 amps overnight. Since I am not in a position to see/ test it then assumption is all I have to work on. Not here for a argument the OP has enough information to make up their own mindWhy are you assuming that?
What with loads still connected and solar
Perhaps it's time for the knowledge bot to appear
I think you have hit the nail on the head! Too many assumptions to know what the true state of the battery was before and after discharge and at what time the reading of 12.2 V was taken the following morning.Why are you assuming that?
What with loads still connected and solar
Perhaps it's time for the knowledge bot to appear
OP
OP
Hi all. Sorry I've not responded to all your interesting suggestions but we've been out and about. Back now.
To respond to some of the points raised. The 12.2V reading was at around 8.30 in the morning. It started to increase before we left the site and had reached 12.7V as we set off at 10.30. Sunny most of today, plus 2 x 15 minute runs on the road. Reading was13V at one point. Now back on site and reading is 12.7V after about an hour pitched up. Nothing drawing other than control panels and router. Heating is off.
But as mentioned by others, the reading is only what the panel is giving.
Once the sun has gone is it possible that the reading will rise if the battery is fully charged?
As Terry said 80 amps is a lot of current to have drawn overnight, if that assumption is correct.
To respond to some of the points raised. The 12.2V reading was at around 8.30 in the morning. It started to increase before we left the site and had reached 12.7V as we set off at 10.30. Sunny most of today, plus 2 x 15 minute runs on the road. Reading was13V at one point. Now back on site and reading is 12.7V after about an hour pitched up. Nothing drawing other than control panels and router. Heating is off.
But as mentioned by others, the reading is only what the panel is giving.
Once the sun has gone is it possible that the reading will rise if the battery is fully charged?
As Terry said 80 amps is a lot of current to have drawn overnight, if that assumption is correct.
Just a thought for you . When you say the battery was at 13.5 Volts when you pitched up its quite possible this is because the alternator would be putting in around 14.4 V when driving to your location assuming the battery was not fully charged when you set off and the reading of 13.5V although a true reading from the battery could have hidden the fact it was not fully charged. (As said before, a battery needs time to settle without any load before you get an indication of its true state.) The other thing that could indicate a large draw from your battery bank is your heating fan. It could be drawing quite a few amps per hour depending on what type it is and how much heating was being circulated. I also wonder if the heating fan was still drawing current from your battery when you measured the voltage in te morning ! A battery monitor would definitely help you understand how much energy your battery is using at any one time and you could simply find out what draw is being taken from the battery by switching your services on and of one at a time and noting the reading on your battery monitor. Depending on the amount of Solar you have and the state of your battery it may take quite a while to fully charge your battery bank. The voltage alone without a measure of capacity used, can be misleading.
That's not going up much voltage wise. I'd expect it to reach 14 point something with solar all day. Could be the battery is not very charged up and the sky is cloudy, could be battery faulty, solar not big enough etc etc
The voltage definitely won't rise after the sun has gone.
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Terry
LIFE MEMBER
12.7 is a full battery. Anything above 12.8 will be either your solar or alternator if engine is running. No good looking at charge within a couple of hours after a run or daylight.Once dark look then and next morning to get a indicator as to charge.12.2 is a almost half depleted battery reading. Only sure way is to get a test done.
OP
OP
Right, that makes some sense. Whenever I've looked at it on the storage compound, (i.e. after several weeks of no use), it always shows around 13.5V. Presumably the reading off the solar. At this moment, 17.15, still daylight, and after having been run out today, it's showing 12.7V. I will note down the readings as the daylight disappears, through the evening, and tomorrow morning.
OP
OP
Anyone know what the heating fan will be drawing? It has two settings, Eco, which you can hardly hear, and High, which is much more noticeable. Obviously that doesn't tell you anything about the draw. Just wondered if there are "typical" figures someone might know. It's a Truma system on an A class Pilote.
What type of solar controller is it? PWM or MPPT? If the label doesn't tell you, what make/model is it? As Richard n Ann says, it looks like you're not seeing voltages of around 14.5V, which is what I would be looking for to see if the battery is being fully charged.
When fully charged, the charger drops the voltage from about 14.5V to about 13.5V. You don't say what wattage the solar panels are, but it takes several hours at around 14V to charge a battery, especially if the solar panel is around 100W and the battery is 180Ah.
One possibility is that the battery is just not getting charged enough, and is consistently not near 100%. This is bad for the battery if it happens over more than a few days. Lead-acid batteries, including gel and AGM types, need to be 100% charged regularly, at least once a week, or they gradually deteriorate due to sulphation.
To repeat what others have said, the voltage of the battery while it is charging or discharging is a very misleading indicator of the state of charge. A proper battery monitor, like the one in Richard n Ann's post#8, continuously measures both amps (in and out) and voltage, and has a microchip with timer that computes the charge into and out of the battery to find the total remaining charge.
When fully charged, the charger drops the voltage from about 14.5V to about 13.5V. You don't say what wattage the solar panels are, but it takes several hours at around 14V to charge a battery, especially if the solar panel is around 100W and the battery is 180Ah.
One possibility is that the battery is just not getting charged enough, and is consistently not near 100%. This is bad for the battery if it happens over more than a few days. Lead-acid batteries, including gel and AGM types, need to be 100% charged regularly, at least once a week, or they gradually deteriorate due to sulphation.
To repeat what others have said, the voltage of the battery while it is charging or discharging is a very misleading indicator of the state of charge. A proper battery monitor, like the one in Richard n Ann's post#8, continuously measures both amps (in and out) and voltage, and has a microchip with timer that computes the charge into and out of the battery to find the total remaining charge.
OP
OP
Well, I will definitely be getting a battery monitor, as I have no idea what is going on at the moment. The controller is a Schaudt LR1218, which I believe is PWM? Last night when we turned in at about 23.00 the control panel was still showing 12.2V, which it had shown since 21.00. This morning at 07.30 it was still showing 12.2V, and as I write has not changed. It is overcast though? I'm not really happy to carry on not knowing whether we may be damaging the battery, so I'll be looking for EHU for the rest of the trip. When we get back I'll try to do a proper test on the battery with no load etc. I may need further advice on how to safely disconnect from the solar.
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6
63720
Deleted User
I knew our LB was gone when the 12v stopped working when wilding on solar and only came back when I started the engine. Unfortunately this was while we were in France so struggled on for a few weeks till we arrived back and replaced it.
I don't know about this particular controller, but PWM controllers generally have a lower voltage than the MPPT type, especially in overcast conditions. I'd go for EHU at least once a week, and if the weather improves you might not even need that.
OP
OP
Yeah that makes sense. What is still worrying me is the drop off in indicated voltage. (I understand the control panel is not simply showing the battery condition). Last night we went from 12.7V at 17.30 to 12.2V at 21.30. With a 180Ah battery this seems worrying. Nothing heavy duty was in use.
Do you know what the current drain was? Ours drops continuously during the night as there is a small ½ amp load 80ah battery drops by about 0.1v. You can see it dropping steeper on the left hand side when the TV is on (total load about 2a)
This seems to confirm your battery is not fully charged and the voltage your seeing during daylight is from your solar panel and as soon as it gets dark your seeing the battery voltage without any solar support. You do not say how much solar you have and I suspect its not enough to fully charge your battery bank. As has already been advised, get onto hook up asap and make sure your battery gets a full charge. You, like most of us learn from these experiences and will overcome these problems. Remember you can never have too much solar.
When you get home you might want to consider doing a test on your battery to see how much capacity is left. According to aandacaravans and Alpha batteries once a leisure battery has lost 20% of its capacity it is regarded as being at its End of Life status. I don't agree with that but I'm just and end user like your good self.
So, How does one do a capacity test on their leisure battery ?
Here is a suggestion by autorouter which I have recently tried and you may want to consider.
1. Fully charge the battery, leave it to settle for a couple of hours.
2. Attach a load that draws an amps value of Capacity/20. (for example for a 100Ah battery, 100/20 = 5A.
3. Run the load for 5 hours. The amp-hours taken from the battery is Amps x 5 hours. (for the same example, 5 x 5 = 25Ah. For a brand new battery this would be 25% of the capacity, so it should be down to the 75% level.
4. Let the battery settle for a couple of hours
5. Measure the voltage.
6. Use this voltage, referring to the battery charge/voltage scale (In Lenny HB's post #32) to estimate what percentage charge is left in the battery. For this example, let's suppose it is 12.28V. If it's a Sealed Lead-acid type, that represents a level of 60%. Since you drew 25% of the label capacity, you would expect the voltage to be at the 75% level on the charge/voltage scale. However because the battery has aged, it is now at the lower level of 60%.
7. If the battery is actually at 60% when you expect it to be 75%, its capacity when full is
(60 / 75) x 100 = 80% of the original capacity.
So the battery capacity has reduced due to aging, and is now only 80% of its original capacity .
I forgot to add the charge chart and here it is.
| Battery Voltage Chart | ||
| Volts | % | |
| 12.7 | 100 | |
| 12.5 | 90 | |
| 12.42 | 80 | |
| 12.32 | 70 | |
| 12.2 | 60 | |
| 12.06 | 50 | |
| 11.9 | 40 | |
| 11.79 | 30 | |
| 11.58 | 20 | |
| 11.31 | 10 | |
| 10.5 | 0 |
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