Battery for Caravan

[RogerL]

For the first 36 years of my caravanning I just used an old car battery, not the same one but a succession of batteries removed from my cars when they'd no long start reliably - an AC Delco from one of my Vauxhalls did 6 years in the car, another 8 years as caravan battery and then a further 6 years as a supplementary battery for off-grid festivals, that's 20 years altogether. The batteries have always been on a smart charger at home and almost always on EHU when away on site - for most of those 36 years, the main use of the battery was to operate the mover.

4 years ago I ran out of old car batteries and although I considered buying a new car battery, given my good experience, but decided to be conventional and buy a good leisure battery, a Yuasa L36-EFB, so you can imagine my disappointment that today's annual service saw the technician fail the battery using his electronic tester, the State Of Health (SOH is down to 22% although the voltage was 13.5v. Some may think that 4 years is a good life for a battery but for me it's woefully short.

I'm tempted to go back to using an old car battery - my VW Touareg is 8 years old this autumn and is "overdue" for its OE battery to be replaced but its battery is too big for the caravan, just by 10mm but it might as well be 1000mm.

 

[ProfJohnL]

If your using sites with EHU, then a car battery should be more than good enough.

 

[otherclive]

Four years does seem short for what is considered to be a good quality make of battery. Difficult to really advise on what goes into the caravan next. My last one was a Banner with old fashioned screw off caps but I only ever needed to top it once in four years. I cannot recall the AWS tech saying anything was untoward with it. But I then sold the caravan so cannot advise on its overall life.

 

[Mr Plodd]

Batteries, of all makes, seem to last a lot longer these days. When I started my apprenticeship as a mechanic back in (no sniggering at the back please) 1969, the "accepted" life of a lead acid car battery was around two, and if you were really lucky, three years. Now 7-8 years is nothing unusual, and in real terms they have got a lot cheaper as well, as back then they were around the 18-20 quid mark!

 

[RogerL]

Batteries, of all makes, seem to last a lot longer these days. When I started my apprenticeship as a mechanic back in (no sniggering at the back please) 1969, the "accepted" life of a lead acid car battery was around two, and if you were really lucky, three years. Now 7-8 years is nothing unusual, and in real terms they have got a lot cheaper as well, as back then they were around the 18-20 quid mark!

It doesn't feel like that to me at the moment - although my experience can't be taken as typical.

I think I'm going to buy a battery tester, one that will digitally measure State Of Health (SOH) as well as State Of Charge (SOC) and capacity - and then monitor it regularly - anyone got any recommendations?

 

[Mr Plodd]

It doesn't feel like that to me at the moment - although my experience can't be taken as typical.

I think I'm going to buy a battery tester, one that will digitally measure State Of Health (SOH) as well as State Of Charge (SOC) and capacity - and then monitor it regularly - anyone got any recommendations?

Always going to be exceptions for everything.

Do you have a solar panel? Do you plug into EHU regularly because deep cycling a battery not designed for it is a sure fire life shortener.

 

[otherclive]

It doesn't feel like that to me at the moment - although my experience can't be taken as typical.

I think I'm going to buy a battery tester, one that will digitally measure State Of Health (SOH) as well as State Of Charge (SOC) and capacity - and then monitor it regularly - anyone got any recommendations?

I assume that you have a multi stage smart charger like CTEK?

 

[RogerL]

Always going to be exceptions for everything.

Do you have a solar panel? Do you plug into EHU regularly because deep cycling a battery not designed for it is a sure fire life shortener.

No solar panel - all caravan sites we use are EHU, maybe an off-grid festival/event once a year - motor mover is the main current draw at home to start/end trips and pitching up on site.

I assume that you have a multi stage smart charger like CTEK?

Yes, I'm an early adopter of smart chargers - our previous 2001 Bailey had an on-board power supply which could be switched off so the CTEK was permanently connected, and powered up, both at home and on site - but our present 2013 Lunar just has an unswitched dumb float charger, maybe I can pull a fuse for the onboard charger and go back to using the CTEK full time.

 

[Woodentop]

Float charging (i.e. constant voltage) will not harm any car or leisure battery. I used to overview the operation of systems for a well known national safety organisation and their systems used constant voltage charging. We did a first change on the batteries when the systems were about 8-9 years old.

Constant voltage charging is very much the norm in professional communications systems so it can't be that bad for caravans, can it?

 

[RogerL]

Float charging (i.e. constant voltage) will not harm any car or leisure battery. I used to overview the operation of systems for a well known national safety organisation and their systems used constant voltage charging. We did a first change on the batteries when the systems were about 8-9 years old.

Constant voltage charging is very much the norm in professional communications systems so it can't be that bad for caravans, can it?

Float charging relies on the constant voltage staying within specification - if the unit becomes faulty and increases the voltage, it'll soon wreck a battery but without any warning until it fails completely.

 

[ProfJohnL]

One of the reasons that 13.8V was adopted as the output voltage of caravan chargers, was the belief that it was high enough to keep a lead acid leisure battery in good condition, without it out gassing. And it was relatively easy (and cheap) to make power the power supplies.

What the manufacture's didn't fully account for was that caravans are often stored for months at a time, and the batteries could often become discharged for long periods, and to safely bring a long-term discharged battery back to good health needs a more sympathetic multistage approach.

Just putting 13.8V to a damaged LA battery can damage it further. And in extreme cases I have seen batteries that have boiled dry and even exploded in caravans.

Even older caravans used to have chargers(not power supplies) that were unregulated, and could produce half or full wave rectification peak charging voltages of 21V or more. These were the days when it was essential to have a battery on board, because one of its jobs was to provide a smoothing and voltage stabilisation to the caravans charger.

 

[RogerL]

An update - after removal from the caravan, 36 hours charging with my CTEK and 12 hours resting, I retested the battery with my newly aquired Foxsur FBT200 battey tester - it passed with flying colours, State Of Health (SOH) 99% compared to the 22% during service.

As I'd not noticed any issues on site or using the mover, I'll put the battery back in and check it again when we come back from our next trip away.