Using to many volts on 12v than EHU? (1 Viewer)

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Jo662
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I suggest you improve your understanding of how much Amps your habitation services use when not on hook up and how this affects your battery life. Batteries will have to work a lot harder in the winter due to temperature and less light when reliant on solar power.


yes I appreciate what you are saying,but I dont think the battery level should of gone down to 11.9v which made the heater shut down because there was not enough power to run it.
 
Aug 5, 2018
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were you also using the fluorescents and the tv at the same time when this dropped to the point things started to shut off?
I havent looked back in the thread to refresh my memory but i believe we were talking about the fluoro lights having a high amp drain... was this just general info or have you directly noted down what they draw on your set up.
You need to do this for the tv as well really and then the heater. See ACTUALLY, how much energy each item uses. Even if the background usage is 0.8 amps, just knock that off your measurements.
Jot them all down and lets see what you were likely using at the time things started to go pear shaped. I do still think you might have a faulty battery but you do need to get to the bottom of your actual usage so you have some concrete evidence that the batteries "should last longer" than they did.
 
OP
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were you also using the fluorescents and the tv at the same time when this dropped to the point things started to shut off?
I havent looked back in the thread to refresh my memory but i believe we were talking about the fluoro lights having a high amp drain... was this just general info or have you directly noted down what they draw on your set up.
You need to do this for the tv as well really and then the heater. See ACTUALLY, how much energy each item uses. Even if the background usage is 0.8 amps, just knock that off your measurements.
Jot them all down and lets see what you were likely using at the time things started to go pear shaped. I do still think you might have a faulty battery but you do need to get to the bottom of your actual usage so you have some concrete evidence that the batteries "should last longer" than they did.



no I did not have the fluorescent lights on when the power dropped as I know they are power hungry!
surely two leisure batteries should run your tv,heater and a couple of LED lights for an evening without running flat. I will try and do as you say and work out the usage of each thing.

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OP
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Jo662
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Celebrate with a bottle or two before bed. That will ensure the need to get up again around 3 - 4am, while it is still dark. Check the voltage then. No charge going in & (hopefully) nothing having gone out for several hours. The batteries will be at their resting voltage & it will give a good indication of their state of charge.

If they show around 12.6V having rested for an hour or so & after having run the TV & lights for a few hours, then they are likely to be ok.

Also check the Battery Amps reading. It should be very close to zero - but the accuracy at low levels might be suspect. Use a torch - don't turn a light on!!


i checked the panel when Everything was off and had settled down and the leisure batteries read 12.4v and the amps read 0.9v!
 
Feb 9, 2008
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i checked the panel when Everything was off and had settled down and the leisure batteries read 12.4v and the amps read 0.9v!
This indicates to me, your batteries are fine and recovered to almost 80% of their total capacity. As I said earlier, it's virtualy impossible to get a true reading of battery state when there is a load on it. Can you recall how many hours your heater, TV, lights etc., was in use. Also, the shutdown by the Sargent system is there to protect your batteries and now you know this works fine. I attach for your information the Amp usage readings of my key Habitation services. You are well advised to do something similar so you have a better understanding of what is going on in your motorhome.

Fridge (on gas)
0.4​
420​
Bedroom LED Lights
1.3​
161.5
Bathroom LED Lights
0.8​
233.3
Kitchen LED Lights
0.9​
210
Habitation LED lights
1.0​
190.9
Outside Door Light
1.1​
190.9
All LED LIghts
2.9​
70
Webasto Hot Water start up
6.0 - 15.6​
For first 90 seconds
Webasto Hot Water running
Webasto Heater running
1.3
8.0 -12.0​
Avtex TV
3.5​
Bedroom TV
1.6​
Toothbrush through Inverter
0.7​
Laptop through Inverter
2.1​
Phone charger through Inverter
0.9​
12 Volt vacuum cleaner through Inverter
1.1​
12 Volt phone/tablet
0.3​
Primus system
1.5​
12 Volt Dyson through Inverter
1.9​
Note: When kill switch activated 0.0 Amp draw.
N.B. Thee figures on the extreem right are number of operating hours left on my Leisure Batteries. (2 X 100 AH)
 
May 7, 2016
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If the batteries have sulphated either through over discharge or under charging then voltage can be very deceptive. The parts of the plates that are not sulphated can charge up to a normal voltage (12.5v+) but the capacity is reduced, so what you think is a 100Ah battery is perhaps only capable of storing 40Ah and will fade away much sooner than you expect.

Think of a 100 gallon tank that is 75% full of scale and rubbish, the tank will look full and the pressure will be normal but after 25 gallons have been drawn off the water flow will drop to a trickle with no pressure. Pressure equates to volts and capacity to Ah.

Sulphation is a something that happens as batteries age but it can be brought on at any time if they have not been fully charged or have been discharged too far but the voltage may well look normal.

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Feb 9, 2008
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If the batteries have sulphated either through over discharge or under charging then voltage can be very deceptive. The parts of the plates that are not sulphated can charge up to a normal voltage (12.5v+) but the capacity is reduced, so what you think is a 100Ah battery is perhaps only capable of storing 40Ah and will fade away much sooner than you expect.

Think of a 100 gallon tank that is 75% full of scale and rubbish, the tank will look full and the pressure will be normal but after 25 gallons have been drawn of the water flow will drop to a trickle with no pressure. Pressure equates to volts and capacity to Ah.

Sulphation is a something that happens as batteries age but it can be brought on at any time if they have not been fully charged or have been discharged too far but the voltage may well look normal.
These are new/ish batteries. Sulphation is unlikely to be an issue.
 
May 7, 2016
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These are new/ish batteries. Sulphation is unlikely to be an issue.
Usually yes but ageing can be seriously accelerated by over discharge or under charging. Perhaps they sat neglected in a warehouse at 10.5 volts for weeks, that could do it. I guess the only way to be sure would be to fully charge them and apply a known load to them and measure the time taken for the voltage to drop. I would be inclined to separate them first. Not easy when you are on holiday.
 
Feb 9, 2008
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Usually yes but ageing can be seriously accelerated by over discharge or under charging. Perhaps they sat neglected in a warehouse at 10.5 volts for weeks, that could do it. I guess the only way to be sure would be to fully charge them and apply a known load to them and measure the time taken for the voltage to drop. I would be inclined to separate them first. Not easy when you are on holiday.
The only problem with your premise is the term 'if' a nd ' perhaps'.

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OP
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Jo662
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This indicates to me, your batteries are fine and recovered to almost 80% of their total capacity. As I said earlier, it's virtualy impossible to get a true reading of battery state when there is a load on it. Can you recall how many hours your heater, TV, lights etc., was in use. Also, the shutdown by the Sargent system is there to protect your batteries and now you know this works fine. I attach for your information the Amp usage readings of my key Habitation services. You are well advised to do something similar so you have a better understanding of what is going on in your motorhome.


Fridge (on gas)
0.4​
420​
Bedroom LED Lights
1.3​
161.5
Bathroom LED Lights
0.8​
233.3
Kitchen LED Lights
0.9​
210
Habitation LED lights
1.0​
190.9
Outside Door Light
1.1​
190.9
All LED LIghts
2.9​
70
Webasto Hot Water start up
6.0 - 15.6​
For first 90 seconds
Webasto Hot Water running
Webasto Heater running
1.3
8.0 -12.0​
Avtex TV
3.5​
Bedroom TV
1.6​
Toothbrush through Inverter
0.7​
Laptop through Inverter
2.1​
Phone charger through Inverter
0.9​
12 Volt vacuum cleaner through Inverter
1.1​
12 Volt phone/tablet
0.3​
Primus system
1.5​
12 Volt Dyson through Inverter
1.9​
Note: When kill switch activated 0.0 Amp draw.

N.B. Thee figures on the extreem right are number of operating hours left on my Leisure Batteries. (2 X 100 AH)





Thanks for the amps used info,very helpful.?

we had the heating and lights on for about four hours I think!
 
OP
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Jo662
May 7, 2011
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If the batteries have sulphated either through over discharge or under charging then voltage can be very deceptive. The parts of the plates that are not sulphated can charge up to a normal voltage (12.5v+) but the capacity is reduced, so what you think is a 100Ah battery is perhaps only capable of storing 40Ah and will fade away much sooner than you expect.

Think of a 100 gallon tank that is 75% full of scale and rubbish, the tank will look full and the pressure will be normal but after 25 gallons have been drawn off the water flow will drop to a trickle with no pressure. Pressure equates to volts and capacity to Ah.

Sulphation is a something that happens as batteries age but it can be brought on at any time if they have not been fully charged or have been discharged too far but the voltage may well look normal.


The batteries are only just over a year old and to my knowledge have never discharged below 11.9v,so i wouldn’t of thought that was the problem.

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OP
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Jo662
May 7, 2011
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Again I agree with you but the symptoms fit and I would have thought it was something to check out if the problem remains unsolved.

yes it is a good idea and.will check them when back next week?

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Feb 9, 2008
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The batteries are only just over a year old and to my knowledge have never discharged below 11.9v,so i wouldn’t of thought that was the problem.
For future use I would advise you not to let your batteries fall below 12.06 V which is 50% and Ideally not below 12.42 V. which is 80%. (Recommended practice is to never let a battery fall below 50% of its D.O.D and ideally do not discharge more than 20%). Although you had a reading of 11.9 V. its more than likely you never fell below 12.06 V (as stated before you cant accurately measure battery state with a load on it and when your batteries were allowed to recover they came back to 12. 4 V). I'm wholly satisfied that your batteries are performing correctly and the fact they recovered from 11.9 V. to 12. 4 V. overnight suggests to me they are in good health. I am unable to understand why fully charged batteries would only last for four hours and the only sense I can make of it, is you were drawing a lot more than 7 Amps. (you have 2 x 100 AH batteries and used 28 Amps meaning 172 AH remaining and 50% of this would mean 86 AH left.
May I ask, is this the first time you have used these batteries off 'hook up' and running the heater, tv, etc. and if not, how many times have you used them off hook up and for how many hours at a time. The only other explanation that would make any sense to me is that the battery capacity has been reduced but more investigation is required about how these batteries have been used by you since new.
 
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i checked the panel when Everything was off and had settled down and the leisure batteries read 12.4v and the amps read 0.9v!
That doesn't sound too bad. Certainly good enough that I wouldn't worry now until you get home. I don't know how accurate the Sargent display is - an error of even 0.1V is significant in this context.

I take it that the fridge was still on & running on gas & that the Amps display actually said -0.9 rather than 0.9 i.e there was a minus sign in front of the zero.

You could try again with the fridge turned off altogether. With the Sargent Control panel switched on & nothing else, the current draw should be no more than -0.2 amps. Anything more than that & there is still something on that you haven't found yet.

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OP
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Jo662
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I'm intrigued to know how you will test them ????



If I took them out so there was no draw on them and then tested them. If got a garage near where I work and they will put a meter on them. Or isn’t that a good way to do it?
 
May 7, 2016
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If I took them out so there was no draw on them and then tested them. If got a garage near where I work and they will put a meter on them. Or isn’t that a good way to do it?
Make sure the battery is fully charged, check the voltage. Attach and run something with a known load like a 21watt bulb and check how long it takes to drop to the 50%/12.06v level. 21watts divide by 12v = 1.75A, 50Ah divide by 1.75A = 28 hours. You could use something a bit more power hungry than a 21w bulb to speed up the test, the sums would be similar. Do not do the drop test favoured by some garages, this is for engine start batteries and would damage a proper leisure battery.
 
Feb 9, 2008
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If I took them out so there was no draw on them and then tested them. If got a garage near where I work and they will put a meter on them. Or isn’t that a good way to do it?
If you take them to a garage and they put a meter on them (what kind of a meter ?) IMO it will be a waste of effort and time on your part. Assuming they put a volt meter on them, all this will tell them is the charge state. (You could do this yourself without taking the batteries out. If they do a cold cranking test (CC test) they will be doing a test that is used for starter batteries and not leisure batteries. (A very poor leisure battery will pass a CC test) ( Although there is a national and international standard for a starter battery, there is no such standard for a leisure battery and the battery industry takes full advantage of this by many, resulting in the production of crap batteries and calling them leisure batteries when in fact they are just cheap starter batteries. However, that is a subject for another discussion). (are you getting the impression that the whole subject matter of leisure batteries is becoming a minefield :swear2: ) ( Welcome to the world of motorhoming).

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OP
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Jo662
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For future use I would advise you not to let your batteries fall below 12.06 V which is 50% and Ideally not below 12.42 V. which is 80%. (Recommended practice is to never let a battery fall below 50% of its D.O.D and ideally do not discharge more than 20%). Although you had a reading of 11.9 V. its more than likely you never fell below 12.06 V (as stated before you cant accurately measure battery state with a load on it and when your batteries were allowed to recover they came back to 12. 4 V). I'm wholly satisfied that your batteries are performing correctly and the fact they recovered from 11.9 V. to 12. 4 V. overnight suggests to me they are in good health. I am unable to understand why fully charged batteries would only last for four hours and the only sense I can make of it, is you were drawing a lot more than 7 Amps. (you have 2 x 100 AH batteries and used 28 Amps meaning 172 AH remaining and 50% of this would mean 86 AH left.
May I ask, is this the first time you have used these batteries off 'hook up' and running the heater, tv, etc. and if not, how many times have you used them off hook up and for how many hours at a time. The only other explanation that would make any sense to me is that the battery capacity has been reduced but more investigation is required about how these batteries have been used by you since new.


We are rarely on hook up as we mainly use aires and go for days out most weekends. It makes me think the solar panel has been disguising the batteries being faulty,is that possible?
 
OP
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Jo662
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Make sure the battery is fully charged, check the voltage. Attach and run something with a known load like a 21watt bulb and check how long it takes to drop to the 50%/12.06v level. 21watts divide by 12v = 1.75A, 50Ah divide by 1.75A = 28 hours. You could use something a bit more power hungry than a 21w bulb to speed up the test, the sums would be similar. Do not do the drop test favoured by some garages, this is for engine start batteries and would damage a proper leisure battery.



Ok thanks for that info,will do?
 
May 7, 2016
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We are rarely on hook up as we mainly use aires and go for days out most weekends. It makes me think the solar panel has been disguising the batteries being faulty,is that possible?
Yes perfectly possible, voltages alone can be very deceptive.

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OP
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If you take them to a garage and they put a meter on them (what kind of a meter ?) IMO it will be a waste of effort and time on your part. Assuming they put a volt meter on them, all this will tell them is the charge state. (You could do this yourself without taking the batteries out. If they do a cold cranking test (CC test) they will be doing a test that is used for starter batteries and not leisure batteries. (A very poor leisure battery will pass a CC test) ( Although there is a national and international standard for a starter battery, there is no such standard for a leisure battery and the battery industry takes full advantage of this by many, resulting in the production of crap batteries and calling them leisure batteries when in fact they are just cheap starter batteries. However, that is a subject for another discussion). (are you getting the impression that the whole subject matter of leisure batteries is becoming a minefield :swear2: ) ( Welcome to the world of motorhoming).


Thanks for the info,so what is the best way to test the batteries?
 
OP
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Jo662
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That doesn't sound too bad. Certainly good enough that I wouldn't worry now until you get home. I don't know how accurate the Sargent display is - an error of even 0.1V is significant in this context.

I take it that the fridge was still on & running on gas & that the Amps display actually said -0.9 rather than 0.9 i.e there was a minus sign in front of the zero.

You could try again with the fridge turned off altogether. With the Sargent Control panel switched on & nothing else, the current draw should be no more than -0.2 amps. Anything more than that & there is still something on that you haven't found yet.


Yes the fridge was still on. And I have a solar display and mppt box for solar than takes some power!
 
Feb 9, 2008
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We are rarely on hook up as we mainly use aires and go for days out most weekends. It makes me think the solar panel has been disguising the batteries being faulty,is that possible?
It is ! This extra information about there usage may throw a bit more light on your issue. It would appear they are well used. Out of interest, how much solar power do you have and can you tell me what leisure batteries you have. (Did I read earlier on that you had 2 Banner lead acid batteries ? if so, that will 200 cycles at 50% D.O.D). If you have been doing a shed load of days out and not using Hook Up, the amount of Solar Power (S.P.) you have is going to be important and the amount of good daylight they will be exposed too ? Assuming you have more power coming from your panels than your using during in daylight hours then your leisure batteries will not be loosing any power and more importantly not cycling. At night, they will be using power and therefore cycling. The amount of Cycling will depend on how far they are discharged. (if you discharge by 50% and then fully charge again, this is one cycle. After 200 cycles they die no matter how much charge you put into them after that point). The drop test referred to above by Pausim will help you establish how healthy your Batteries are. Unfortunately, it wont tell you how much life is left in them as you can still fully charge a leisure battery that has very little capacity left.

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Feb 9, 2008
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I now see they are Bosch. If it's the LFD90 they are the equivalent of the Varta LFD90 (might even be the same battery). The Varta LFD90 is for low to moderate motorhome use, according to it's own website.
 
May 7, 2016
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I now see they are Bosch. If it's the LFD90 they are the equivalent of the Varta LFD90 (might even be the same battery). The Varta LFD90 is for low to moderate motorhome use, according to it's own website.
It also says it is dual purpose, which probably means it does neither job particularly well.

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