yoko8pups Posted January 27, 2019 Share Posted January 27, 2019 Our 12 volt is only going up to 12.5 even after a long run, we have 2 leisure batteries and I accept that we will probably have to replace them, they have lasted more than 4 years. What I am puzzling about is that when nothing is using any power the display says it is drawing .4 but if you switch a light on it only draws .3. Is something draining it when there is nothing in the cab using it? Fridge is on gas. Link to comment Share on other sites More sharing options...
Grumblewagon Posted January 27, 2019 Share Posted January 27, 2019 Firstly, I assume that the battery voltage is 12.5V after a run. What is the battery voltage with the engine running? You should ideally check this at the battery itself, and this will tell you if the battery is being charged properly. 4 years isn't all that old. As for battery drain, I think that you need a test meter to check if there is an actual battery drain, or whether the control panel is faulty. If there is a drain, then you can possibly isolate it by removing fuses to see what is taking the power. Link to comment Share on other sites More sharing options...
yoko8pups Posted January 27, 2019 Author Share Posted January 27, 2019 Thanks, it is 13 with the engine running. The batteries are at least 4 years, that is how long we have had it. The person we bought it from said the second one was fairly new and gave me the receipt so I will check tomorrow. We just did 150k and it was 13 when we stopped but within 10 mins back to 12.5. I guess I'll take fuses out to see when I'm cleaning it tomorrow! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted January 27, 2019 Share Posted January 27, 2019 For a 2005 Hymer C524 (like yours) when the motorhome’s engine is running and its alternator is charging the batteries, it would be expected that a voltage reading taken at the battery terminals would exceed 14V. So, as your motorhome’s display is only reading 13V when the engine is running, this casts doubt on the display’s accuracy (or there’s something wrong with the charging system). I suggest that - before you consider dumping the batteries - you follow Grumblewagon’s advice and take multimeter readings. If the display is lying about the voltage, it could also be lying about the ‘drain’. Link to comment Share on other sites More sharing options...
Brian Kirby Posted January 27, 2019 Share Posted January 27, 2019 To prolong their lives, both batteries need to be, as nearly as possible, identical, both in terns of type, but also age. If one was newer than the other when you got the van, it is probable that the older battery had dragged down the newer one. Re your (I assume) voltmeter readings, if you fridge is on gas the fridge is on, and when on its control panel will draw current. I can't comment on why that reading should fall when a light (you don't say whether tungsten or LED) is switched on: it may be a fault on the panel, as suggested, or it may be a quirk of the panel when very low loads are being measured, or even how the apparently tired batteries respond to the extra load. As suggested above, you need to meter what is happening at the batteries themselves to check whether the panel is telling the truth. (I'd suggest you measure separately at each battery, and then by bridging the + on one to the - on the other.) Also, while there, check the condition of the large fuse and holder (50A or so: it should be near, or incorporated into, the + battery connector.) on the + side of the batteries, and also the conditions of the battery terminals. Don't forget to make sure the mains charger is isolated, and be very careful not to short either of the battery + terminals to earth! Link to comment Share on other sites More sharing options...
aandncaravan Posted January 27, 2019 Share Posted January 27, 2019 Brian Kirby - 2019-01-27 6:22 PM As suggested above, you need to meter what is happening at the batteries themselves to check whether the panel is telling the truth. (I'd suggest you measure separately at each battery, and then by bridging the + on one to the - on the other.) Don't forget to make sure the mains charger is isolated, and be very careful not to short either of the battery + terminals to earth! Brian, If the batteries are connected together in the usual way, then putting a multimeter on either one will only ever reveal the voltage of the 'highest' battery. The batteries would need to be electrically separated in order to be able to see each individual batteries true voltages, which is what I think you were suggesting would be a good idea? Just removing the negative clamp from one of the batteries, and insulating it so it doesn't touch anything, is probably the easiest way to isolate them? Is it possible you have a Solar panel and you are confusing the 'draw' with a Solar charge, it isn't always easy to work out which is which on some of the Schaudt LCD displays? That would explain why it reduces when you put on a light? If you do have Solar, suggest you isolate the Solar panel from the solar regulator before doing any battery work? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted January 28, 2019 Share Posted January 28, 2019 It might be worth revisiting this September 2018 forum thread (particularly the last two postings there) https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Leisure-battery-failure/50323/ Link to comment Share on other sites More sharing options...
aandncaravan Posted January 28, 2019 Share Posted January 28, 2019 Thank you Derek, very useful reminder and lots more history. Yoko8pups, as you state at the end of the last thread from September your knowledge of electricity isn't great, "I am ignorant of the workings of electricity, sorry. My husband isn't at all curious about how anything works so I have to do it. When the 12 volt alarm went and then we were blacked out the TV which was connected to the other leisure battery kept going so they may not be parallel". In order to go forward you need to know how the batteries are wired before any meaningful diagnostics can be interpreted, so I repeat my comment in the last thread - "Then I would suggest you get your local repair man to do a full 12v survey to tell you exactly how the batteries are wired and connected together. Should only take 30 mins, so shouldn't cost much. He will then be able to make an assessment as to why the 50a fuse failed and give you an idea of what issues you have or are likely to crop up in the future". Finding out the reason the 50a fuse blew is key, as that is a lot of 'electronics damaging' current, possibly putting the alternator, mains charger, etc at risk. Link to comment Share on other sites More sharing options...
Brian Kirby Posted January 28, 2019 Share Posted January 28, 2019 aandncaravan - 2019-01-27 7:21 PM Brian Kirby - 2019-01-27 6:22 PM As suggested above, you need to meter what is happening at the batteries themselves to check whether the panel is telling the truth. (I'd suggest you measure separately at each battery, and then by bridging the + on one to the - on the other.) Don't forget to make sure the mains charger is isolated, and be very careful not to short either of the battery + terminals to earth! Brian, If the batteries are connected together in the usual way, then putting a multimeter on either one will only ever reveal the voltage of the 'highest' battery. The batteries would need to be electrically separated in order to be able to see each individual batteries true voltages, which is what I think you were suggesting would be a good idea?...………………………. Correct Allan, I didn't make that at all clear. :$ Thanks. Link to comment Share on other sites More sharing options...
yoko8pups Posted January 28, 2019 Author Share Posted January 28, 2019 Derek Uzzell - 2019-01-27 6:17 PM For a 2005 Hymer C524 (like yours) when the motorhome’s engine is running and its alternator is charging the batteries, it would be expected that a voltage reading taken at the battery terminals would exceed 14V. So, as your motorhome’s display is only reading 13V when the engine is running, this casts doubt on the display’s accuracy (or there’s something wrong with the charging system). I suggest that - before you consider dumping the batteries - you follow Grumblewagon’s advice and take multimeter readings. If the display is lying about the voltage, it could also be lying about the ‘drain’. Yesterday we drove 2 hours all the way across the Algarve, when we got home it said 13, by the time we'd unpacked it was 12.5 and 12.2 this morning with the12 volt off all night. Recently we have been stuck unable to retract the step without turning the ignition on because there is no 12 volt power left at all. Link to comment Share on other sites More sharing options...
yoko8pups Posted January 28, 2019 Author Share Posted January 28, 2019 Brian Kirby - 2019-01-27 6:22 PM To prolong their lives, both batteries need to be, as nearly as possible, identical, both in terns of type, but also age. If one was newer than the other when you got the van, it is probable that the older battery had dragged down the newer one. Re your (I assume) voltmeter readings, if you fridge is on gas the fridge is on, and when on its control panel will draw current. I can't comment on why that reading should fall when a light (you don't say whether tungsten or LED) is switched on: it may be a fault on the panel, as suggested, or it may be a quirk of the panel when very low loads are being measured, or even how the apparently tired batteries respond to the extra load. As suggested above, you need to meter what is happening at the batteries themselves to check whether the panel is telling the truth. (I'd suggest you measure separately at each battery, and then by bridging the + on one to the - on the other.) Also, while there, check the condition of the large fuse and holder (50A or so: it should be near, or incorporated into, the + battery connector.) on the + side of the batteries, and also the conditions of the battery terminals. Don't forget to make sure the mains charger is isolated, and be very careful not to short either of the battery + terminals to earth! After a scary journey back a couple of months ago with no possibility to shut the step even with the engine running our local motorhome fixer replaced the 50A fuse so that was the first thing we checked this time, thanks. Link to comment Share on other sites More sharing options...
yoko8pups Posted January 28, 2019 Author Share Posted January 28, 2019 aandncaravan - 2019-01-28 9:25 AM Thank you Derek, very useful reminder and lots more history. Yoko8pups, as you state at the end of the last thread from September your knowledge of electricity isn't great, "I am ignorant of the workings of electricity, sorry. My husband isn't at all curious about how anything works so I have to do it. When the 12 volt alarm went and then we were blacked out the TV which was connected to the other leisure battery kept going so they may not be parallel". In order to go forward you need to know how the batteries are wired before any meaningful diagnostics can be interpreted, so I repeat my comment in the last thread - "Then I would suggest you get your local repair man to do a full 12v survey to tell you exactly how the batteries are wired and connected together. Should only take 30 mins, so shouldn't cost much. He will then be able to make an assessment as to why the 50a fuse failed and give you an idea of what issues you have or are likely to crop up in the future". Finding out the reason the 50a fuse blew is key, as that is a lot of 'electronics damaging' current, possibly putting the alternator, mains charger, etc at risk. We are booked in for next Monday, thanks for you help. Link to comment Share on other sites More sharing options...
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