# Why is my battery going flat?



## Chrisgd

A couple of months ago I had a new starter battery fitted as it would only hold a charge for a couple of weeks before going flat.
This morning the battery was again flat, I last used the motor home about 4 weeks ago, driving 200 miles, so it should've been fully charged. Also the van is always, when on the drive connected to mains. 
The first question I have is should the Sargent 2007 mains box charge the starter battery as well as the leisure batteries?
Secondly does anyone have any suggestions as to why the battery looses it's charge, I've checked several times and everything seems to be turned off

Cheers

Chris


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## BrianJP

Dont know about the Sargent charger but I would guess it doesn't charge the engine battery as it would keep it charged regardless of any other problem.Unless of course this is causing your problem.
So that would mean that either the replacement battery itself is faulty (it does happen) or something is draining the battery which I would say is most likely.
Unless you are able to put a meter in series with the battery to check for current drain just disconnect it for a few weeks and then reconnect and see if it is ok. A new battery fully charged should hold its charge for many months.


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## tyreman1

I had the same problem with my old Swift Escape,there are different settings on the Sargent system for charging the cab battery,best to have a look on the sargant website......i did end up fitting a solar panel on the roof then set the charging sysyem to "solar smart" and it was great even if not used for a couple of weeks.


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## safariboy

If you have a reasonably modern base vehicle this is normal. The starter battery load when everything is turned "off" is likely to be about 150 - 200 mA and this will flatten the battery in about 3-4 weeks. (security system computers that run all the time etc.)
If you look at your instructions it will tell you how to remove the earth connection to the battery to stop this discharge.
The only other solution is to arrange for the charger to run all the time. (Check but usually OK) or have solar panels. I have a 140W panel that is OK for most of the year but have to connect to mains in December and January if not using the van.

It is likely that the habitation battery is not discharging if you turn the control panel off. Set ups are not all the same so you need to get advice from the manufacturer.

But............ don't let the batteries get discharged or stay discharged for more than a day or you will need a new one.


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## dolcefarniente

Sargent have an excellent attitude to e mail enquiries. If your 
PSU is the smart charge type it will alternate between leisure and starter. Sargent will confirm type if you mail your van and PSU details. If you have a drain when parked then as suggested disconnect the battery for a few weeks. If ok after this test use a digital meter set to DC amps (usually 10A symbol) making sure you swap red lead to correct socket on the meter. Leave batt lug off and put the meter in line and wait 5 minutes for all electronics to shut down. Reading should be negligible (0.01 amps or so). Don't switch anything on while meter is in line. Best of luck.


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## dolcefarniente

150 - 200 ma will flatten a battery overnight.


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## Broom

Hi Chris

I have to switch my 2008 motorhome over to charge the vehicle battery on the Sargents box above the door.

Before fitting the Solar Panel I had to charge it around every 3 to 4 weeks when not in use, since fitting Solar Panel never use battery charger.

Best Regards
Broom


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## safariboy

dolcefarniente said:


> 150 - 200 ma will flatten a battery overnight.


200mA will discharge the battery by 4.8A-Hr each day. (0.2 x 24)
50 A-Hr would be the normal maximum discharge for a 110A-Hr battery so you are looking at about 10 days.


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## dolcefarniente

All correct for a fully charged 1280 sg battery. Very few are. They also get to the point of no start at about 60% charge. 200 ma = flat every morning for most average use vehicles and definitely for your average underused camper. I deal with such problems daily. The mathematics is correct but the real world isn't a lab.


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## 100127

I left my MH for two weeks, unplugged from mains and with the Sargent switched off. Got back and checked, both batteries still at 12.5. My Sargent (unless you set it otherwise ) will charge the leisure battery first and then the the vehicle battery. Works for me. I am sure Ian at Sargents will put you right when he spots your post.


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## dolcefarniente

I use mine regularly but it has been left for 6 weeks no problem. My vito gets left for months no problem. My previous van was left all winter and still started.


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## safariboy

This is a problem with some vans only. The Fiat X250 seems to be one of them but I expect that the equivalent in other makes may be as bad. It does also depend on other added security systems.
It arrises because various bits of electronic equipment run all the time even if the key is removed. The wiring is totally unlike the sort of circuits we are used to.


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## Mikeclaire

Ooooo look my first post!!!  
Had the same problem with our battery (cab side), get an auto electrician to have a look at it. Ours was the onboard van computer not shutting down and draining the battery down over a couple of days. 
Mike.


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## Chrisgd

Thanks everyone for their comments, I had an email from Sargent today, explaining I need to switch the control panel from leisure to cab battery, it should then charge up ok, so I try that when I get home.

Thanks again

Chris


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## dolcefarniente

That'll cure it Chris but you shouldn't have to do any charging if the base vehicle is as it left the factory. The adding of habitation shouldn't affect the base if done correctly. Vehicle batteries shouldn't go flat when left or every car would do so. Your average daily use car drives to work 20 mins,drives home 20 mins and is left parked 23hrs and 20 mins and they don't go flat. There is always a cause.


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## thegamwellsmythes

Just a thought but if you had a new battery fitted make sure that the earth cable from the battery to the bodywork has a good connection at the bodywork end.

Ours for some reason was very loose so the battery charged very badly. I tightened it up and the battery charges fine now when being driven.


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## Chrisgd

thegamwellsmythes said:


> Just a thought but if you had a new battery fitted make sure that the earth cable from the battery to the bodywork has a good connection at the bodywork end.
> 
> Ours for some reason was very loose so the battery charged very badly. I tightened it up and the battery charges fine now when being driven.


Will do cheers


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## bijgouder

*Battery drain*

Not sure whether I should have started a new thread, but I have a similar problem.

A couple of weeks ago, my Bessacarr E795 wouldn't start. The AA man checked the battery and said it was unserviceable. A new battery was then installed, but when I returned a week later, was flat again. The new AA man connected a meter to the battery, which showed a drain starting at 11 amps and settling at around 7-8 amps. After switching some of the habitation controls on and off, the cab battery drain settled to about 0.4 amps, which I am told is acceptable.

I used the vehicle over the last few days, returning home yesterday. Whilst it did start, I didn't feel it was quite as effortless as I would expect from a brand new

I know I should probably get an auto electrician to check it out, but wondered if there are any other suggestions out there as to cause or remedy.

Thanks in anticipation.

David


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## dolcefarniente

bijgouder.........get it checked. I'm a self emp veh elec and I've already explained earlier in the thread that 200 ma is unacceptable as a constant drain so your 400ma (.4A) definitely is. When checking current drain with a meter set up the meter so you can see it. Close everything and lock the van. It will take several minutes to reduce to the true current draw. Anything above 10 - 20 ma is too much. You may get away with up to 50 ma in a daily use reasonable mileage vehicle. Hope it helps.


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## roadwarrior1

*i have a zig charger*

after reading and learning a little - i find my engine battery is not being charged when the mains is plugged in - so i had a shock when i found the new battery was flat as a pancake after assuming it was being winter charged via the mains connection - i have a 2001 2.8 autotrail 635..
i have a zig x70 charger, any ideas gratefully recieved


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