"Low vehicle battery" warning.

Broadway FB 6months old .
Battery died before Christmas after being left for 3weeks. Had to get AA out. Is it true that once it's run completely down it's never the same again?
Had other motorhomes and left them longer with no problems.
Just driven 45miles and it's only showing 12.5 on the over the door panel.
I'd been switching the panel off when leaving it but dealer recommends also turning main box off under the bench seat. This doesn't seem to have made any difference.
It's in storage so can't be hooked up when left.
Wendy.

When a lead acid battery goes flat the lead starts falling apart. You MAY be lucky and revive it but that would be very unusual. Genuine leisure batteries can sustain deeper discharges as their lead plates are thicker but most batteries today are compromises between starter and leisure batteries.

Even when switched off some current will be taken for alarms and radio codes. Even with the panel turned off I doubt if these will be taken out of the circuit.

Given that failiures ALWAYS happen at the most inconvinient time I would be inclined to change it before the season really gets underway.

With modern vehicles; if you are going to leave for more than two weeks without any form of charging you should disconnect the starter battery or it will be discharged by the many circuits that are still active with the engine off. This is clearly stated in the Mercedes, Vauxhall and Mazda handbooks of the vehicle I own.

Hi Wendo, like you found our starter battery to be flat on visit to van (in storage) after prolonged absence of seven weeks. RAC had to use his van to jump start it whereby diagnostic reading showed only 1v and one cell dead. Perplexed as to cause when 80 watt solar panel was inputting 1.6 amps into leisure battery albeit reading LOW. The starter battery being in that state was a write off so had to replace at cost of £79. The main box under the seat that you refer to is likely to be the EC500 Power Supply Unit PSU. It is important to leave the SHUTDOWN SWITCH ON otherwise the solar panel will only charge the leisure battery. Your user manual should explain this under BATTERY CHARGER ' intelligent three-stage battery charger / power converter. The fact that after a run off 45 miles the engine battery was showing 12.5v on the control panel appears to be a good outcome. However, it will be 'a wait and see' with regard to if the battery will continue to hold it's charge over time. This morning took our van for a 20 mile spin to bring the battery up from 11.9v to 12.5v. Also during a brief stop for coffee, the EC 480 control panel illustrated the solar panel was putting in 0.2 amps into the vehicle battery. Hope your V batt behaves itself from now on. Regards

Hi Wendy, as Dave said it is more than likely the battery will not recover and the cost of new will be cheaper than a failure somewhere totally inconvenient.
And as Peter suggested you do need to disconnect the vehicle battery when left. (Negative terminal).

:allthumbz:One of the selling points with our Rienza was the solar panel. I then fitted a new vehicle battery and a battery master. So far it seems to keep the leisure and vehicle batteries charged even in the winter with limited sun. 
From my time at the roadside the bench mark for batteries was a life of three years. This is not a sales ploy and should be backed up by the correct  battery test procedures. To prove this the vehicle  battery on our Rienza was eight years old, no wounder it was sluggish to start.  

Dave 418 wrote::allthumbz:One of the selling points with our Rienza was the solar panel. I then fitted a new vehicle battery and a battery master. So far it seems to keep the leisure and vehicle batteries charged even in the winter with limited sun. 

This matches my experience with this van and the last two, batteries always fully charged when the van not in use but not overcharged and damaged by constant mains charging (the sun hides at night and gives the batteries a rest)

Dave 418 wrote:From my time at the roadside the bench mark for batteries was a life of three years. This is not a sales ploy and should be backed up by the correct  battery test procedures. To prove this the vehicle  battery on our Rienza was eight years old, no wounder it was sluggish to start.  

Absolutely agree, any trouble after 3 years old and battery replaced without question.  That said the batteries in both our cars expired in 2016 during their eighth year but they were treated with TLC and always disconnected when away for more than a couple of weeks.

The van is now 5.5 years old and I intended to replace all three batteries (as I have the tyres) as preventative maintenance.  Mark Burdett has talked me out of it until he's had a chance to test them on the basis of his experience that if the batteries have been looked after they will last longer.

I have a 16 year old Lexus 4x4; it lives in the garage, coming out occasionally to notch up some 2K miles annually. When not being driven, its connected to an AirFlow battery conditioner, designed for classic vehicles kept in similar conditions. After 12 years the original battery seemed fine, but I chickened out and took preventive maintenance, replacing it.

The inbuilt Sargent unit in the A/S is similar: it will provide a float charge to maintain the battery to which the charge is directed. So, based on my experience with the AirFlow, I see no reason why the A/S should not be kept permametly hooked up to mains when not being driven. I am able to do that at home. I set the Sargent to charge the vehicle battery, leaving the solar panel to top up the two batteries (with most going to the leisure because the vehicle is being charged by the Sargent).

So far, so good...

I let my vehicle battery go down to 2V 2 or 3 years ago by not noticing its state of charge for a couple of months. I was pessimistic about its chance of recovery but it has been OK since, other than never showing a full 12.8V after being charged.  I don't think it goes above 12.5V now.  But it always starts without problems.
So I have shortened its life and cannot let it happen again.  Sadly I did not get in on the 950VA battery change exercise before Peugeot shut the door.

Replaced our wee cars battery last month, its was 10 years old and had discharged more than once, as Peter and others have said, if you look after them etc
Boaby.  

Cymro wrote:So, based on my experience with the AirFlow, I see no reason why the A/S should not be kept permametly hooked up to mains when not being driven.

My Celex (with Sargent EC328) has been on hookup permanently when not being driven for nearly 4 years now. The batteries are showing no signs of any adverse effects at all.

-mojo- wrote:

Cymro wrote:So, based on my experience with the AirFlow, I see no reason why the A/S should not be kept permametly hooked up to mains when not being driven.

My Celex (with Sargent EC328) has been on hookup permanently when not being driven for nearly 4 years now. The batteries are showing no signs of any adverse effects at all.

I can't dispute your experience with the EC328 and later, but with any of the earlier systems I would not risk overcharging. In particular the EC325 should not be left permanently on as the load is disconnected from the battery when the charger is switched on, it is not float charged but saturated. With the EC325 it is also important to switch off the charger for a day every few days when camping on site.

Thank you, Peter, for that authoritative qualification to the continuous use of a Sargent system. It distinguishes the capabilities of the various systems, and will be of help to Forum members in deciding whether their particular system is designed to be left permanently coupled.
Cymro

No-one has ever explained why this problem seems to affect motorhomes (commercial vehicles) but not cars. Fly off abroad for a month or go over to the continent for 3 or 4 months, come home and your car starts first time. Surely cars have just as many drains on a battery, most have alarms and all have radios. My neighbour went to France last year for 4 months, came home to his Hyundai which started first time. Motorhome engine batteries are surely isolated from the leisure battery when not being used. Could anyone explain please.

Can't answer Paul's question other than it's all about capacity and current draw. If the capacity exceeds the draw then fine. (Peter will know ).
That leads to batteries that 'seem' to be fine. They may well start the car or give you 12 volts when on EHU but you will find the available capacity deteriorates over time so your 100 AH slowly becomes 30AH (hence the three year recommendations if it is critical piece of kit) and you only find this out when you need it most. Off EHU or cold cold morning and engine needs a bit more cranking but doesn't 

A battery that has gone flat will have 'seriously' reduced capacity albeit still giving reasonable off load voltage.

Thank you all for your responses. It has been very helpful.
Wendy.

Paulmold wrote:No-one has ever explained why this problem seems to affect motorhomes (commercial vehicles) but not cars. Fly off abroad for a month or go over to the continent for 3 or 4 months, come home and your car starts first time. Surely cars have just as many drains on a battery, most have alarms and all have radios. My neighbour went to France last year for 4 months, came home to his Hyundai which started first time. Motorhome engine batteries are surely isolated from the leisure battery when not being used. Could anyone explain please.

I think I am right in saying Paul that your experience is based on a car used daily, often for long trips so always with a fully charged battery.  Many of us only use the car a couple of times a week maybe for ten miles or so at a time, so the battery never gets fully charged (particularly at this time of year).  A trip of an hour or so to an airport won't help much and after a couple of weeks the alarm and other monitoring circuits will discharge the battery.

This is clearly stated as an issue in my car handbooks with the advice to disconnect the battery if the car is to be left more than a couple of weeks, as indeed is the Mercedes advice for the van.

I first hit this problem when I retired and started to use the MX5 out of choice, sometimes not using the Vauxhall for 4 or 5 weeks and finding the battery dead when I did.  Now I make a conscious effort to make sure both cars get regular use and still nearly got caught out with the Mazda not being used for over three weeks over an extended Christmas and New-Year, if it hadn't been garaged I'm sure it would not have started.

Each to his own, but personally when I return home from several weeks away and need to collect cats etc. the couple of minutes that it takes to reconnect the battery is no hassle when you know the car will start.

Won't it also disconnect any alarm and also central locking but more importantly, invalidate your insurance if the alarm is immobilised.
Plus you have to reset your clock and radio stations.

Paulmold wrote:Won't it also disconnect any alarm and also central locking but more importantly, invalidate your insurance if the alarm is immobilised.
Plus you have to reset your clock and radio stations.

Yes - all of that but I still do it.

I understand that the latest Boxers (reading about same problem on a Fairford on a FB group) even have a quick-release earth strap so you can do it. So glad my solar panel keeps everything OK.

I'm lucky in the fact that my Motorhome and previous Motorhomes/Caravans I have had are kept on the premises with a mains connection at all times and more recently a Solar Panel.

The only non stating issue being when the local Fiat Dealer didn't tighten up the battery connection up after a service. 

Green Flag to the rescue 

Eltel

PLOUGHLIN wrote:According to my Merc manual, it has a quick release earth to the vehicle battery, but I have not found it yet.

Likewise   . It is supposed to be a master cut off switch but I think may be an optional extra and as it probably costs about £2 extra at time of build it wasn't chosen by AS.