Battery running too low? (1 Viewer)

Sam

Free Member
Aug 19, 2009
29
0
Cornwall
Funster No
8,047
MH
Coach Built
Exp
1
Hi All,

Tried to find an answer to this by doing a search on the forum but gave up after the 6th or so page.

My MH has one leisure battery. When hooked up, it reads 14V. When freshly charged it reads about 12.1-12.3V. When a couple of lights (not LED) and the music is on for about 2-3 hours and some usage of the water pump, it goes down to around 11.2-11.5V.

Question 1: Does this sound reasonable? My heating runs on gas.

Question 2: To what voltage do I let it drop before I worry about damage to the battery?

Question 3: Would running the car on idle for 30mins or so make a big difference? I am under the impression that the alternator does not produce any decent charge unless the engine runs at least 2000rpm

Final question: How many batteries should I have If I want to be independent for at least 36 hours with lights, some music or TV for some of the time?

Thanks lots in advance!
 

savantuk

Free Member
Jul 3, 2009
735
42
Cumbria, Lake district UK
Funster No
7,350
MH
Coachbuilt
Exp
30 years.
It seems that your battery is dead:cry:

A 12v battery, fully charged, should read around 12.7V, when not supported by the mains. Once it get's to around 12.3V, it's for all intents and purposes flat. 12V and below, means that the battery is beggared. If it's reading below 12V, it's quite likely that the plates are buckled, and sulphated, and no amount of charging will bring it back from the dead.

I'm very much afraid, that if your volt meter is accurate, you'll need a new battery. There is not even any point in checking the electrolyte levels, and re-charging.

The reason it reads 14.2V when on charge, is simply because that should be the maximum voltage whilst charging. As soon as the charger is disconnected, the voltage will drop very quickly, because th battery is unable to support a charge.

Once you have fitted a new battery, it's worth swapping out any halogen or other incandescent bulbs for LED substitutes. You can run 9 or 10 of these for the same consumption as one halogen. Better yet, but a solar panel of 80 watts or more, and assuming that you don't use a 12v television, or other power hungry devices, you should be self sufficient for as long as you need. I've lasted 3 weeks, and never had the battery drop below 12.6V.
 
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JJ

Mágica
May 1, 2008
19,258
48,031
Quinta Majay, Pinheiro Bordalo, Portugal
Funster No
2,459
MH
Burstner Privilege T
Exp
over 50 years
I agree with Savantuk... you have the exact symtoms I struggled with for weeks... I replaced the leisure battery(s) with new and all running brilliantly now...

JJ

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Scout

LIFE MEMBER
Apr 4, 2009
3,959
121,136
South Yorkshire
Funster No
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MH
chic c line
Exp
12 years motorhoming, a lifetime of living
you have a defunct battery, it is no more, its gone to happy land of dead cells


please buy another



you know it makes s............
 

vwalan

Funster
Sep 23, 2008
8,835
5,798
roche cornwall
Funster No
4,148
MH
lynton5th wheel
Exp
since a child
hi sam , visit cornwall batteries at threemilestone industrial estate . probably the cheapest place in cornwall for batteries .
 

Wildman

Free Member
May 30, 2008
0
8,470
Ilfracombe, Devon
Funster No
2,913
MH
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Exp
since 1967
dare I suggest it your battery is knackered and you need a new one.

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Tony Lee

Free Member
Sep 28, 2008
274
2
Funster No
4,196
Sam, I see you have been MHing for a year so if your MH is also a year old, it might be worth reviewing your system and how the battery is treated to see if that has contributed to an early demise.
If the battery is three or four years old then there may be no problem but otherwise just replacing the battery may lead you to be asking the same question in a year and that would be a waste of money.

Practices that kill a battery quite quickly include never charging your battery up in the first place, using a cheap taper charger and leaving it connected for days, and running the battery almost dead flat and not charging it up immediately it does get discharged.
 
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Sam

Sam

Free Member
Aug 19, 2009
29
0
Cornwall
Funster No
8,047
MH
Coach Built
Exp
1
Thanks for all the advise everyone very useful indeed. Alan, Thanks for the tip on where to source a cheap one :thumb:

As I've only had this MH for a few weeks I suspect the battery was gone already when I got it...

What size battery do you recommend I should get? more than one? The existing one is under the passenger seat. I guess I could fit another under the driver seat. Can I connect the second battery in line with the first one, or should it be a parallel connection to the charger?

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DESCO

Free Member
Mar 11, 2009
2,646
266
London
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5,894
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low profile
Exp
18 years +12 years tugging
Thanks for all the advise everyone very useful indeed. Alan, Thanks for the tip on where to source a cheap one :thumb:
What size battery do you recommend I should get? more than one? The existing one is under the passenger seat. I guess I could fit another under the driver seat. Can I connect the second battery in line with the first one, or should it be a parallel connection to the charger?

Hi Sam
The obvious answer is as large as possible, with the batteries in parallel if you go for two.
I would tend to see what you can fit in easily and take it from there. If you do decide to link two use thick wire to connect to avoid loss in cable with a fuse in the pos line to protect the wiring. You may find that you can get a larger one in the present location, would make life simpler. Depends on how you camp with EHO or without.


Dave:thumb::thumb:
 
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Sam

Sam

Free Member
Aug 19, 2009
29
0
Cornwall
Funster No
8,047
MH
Coach Built
Exp
1
Hi Sam
The obvious answer is as large as possible, with the batteries in parallel if you go for two.
I would tend to see what you can fit in easily and take it from there. If you do decide to link two use thick wire to connect to avoid loss in cable with a fuse in the pos line to protect the wiring. You may find that you can get a larger one in the present location, would make life simpler.


Dave:thumb::thumb:

Thank you Dave,

Problem actually solved. The dealer I bought from was very happy to put a new one in ::bigsmile:(I thought after the clutch he would not want to know...).
He managed to fit a 110 replacing the 85 that was there before, so I'll see how that goes

All the best
 

Wildman

Free Member
May 30, 2008
0
8,470
Ilfracombe, Devon
Funster No
2,913
MH
Amazon Ambassador
Exp
since 1967
Thanks for all the advise everyone very useful indeed. Alan, Thanks for the tip on where to source a cheap one :thumb:

As I've only had this MH for a few weeks I suspect the battery was gone already when I got it...

What size battery do you recommend I should get? more than one?
It really depends on usage, but if you have room then the more the merrier, 110-120 amp/hr. If you have the room fit a matched pair and connect pos to pos -neg to neg. That would give you 110 or 120 amp hours of use. (you should never allow a battery to get lower than 50% charge).

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pappajohn

LIFE MEMBER
Aug 26, 2007
43,323
49,427
Dark side of the moon
Funster No
172
Exp
Since 2005
hi sam,

have a look at this page from the downloads on here.

scroll down to page 3.

never allow your battery to get to 50% discharge and better to stick to 60%.

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