Battery

[ARTPLUM]

Just had my habitation inspection on the motorhome and they told me my battery failed a drop test the battery is only 4 years old and they said it is because I leave it plugged into the mains over winter when it’s laid up and they told me to only plug it in every 3/4 weeks I had a caravan for nearly 50 years and didn’t have that problem with the battery on that (what’s the best way to keep it topped up) I’ve took it off charger in up and it’s holding a good charge
Cheers Arthur.

 

[hja]

I don’t know anything about the science of this but was under the impression that it was not good to leave on hook up without some usage taking place.

 

[poppycamper]

Just had my habitation inspection on the motorhome and they told me my battery failed a drop test the battery is only 4 years old and they said it is because I leave it plugged into the mains over winter when it’s laid up and they told me to only plug it in every 3/4 weeks I had a caravan for nearly 50 years and didn’t have that problem with the battery on that (what’s the best way to keep it topped up) I’ve took it off charger in up and it’s holding a good charge
Cheers Arthur.

Battery type????

 

[ARTPLUM]

 

[pappajohn]

All depends on the charger.
If it's a modern intelligent charger it could be left on for years.
If it's an old analogue charger it would most likely overcharge the battery and boil it dry over time

If what they say was the problem the battery wouldn't have lasted 4 years.
More likely it's losing capacity due to age.

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[ARTPLUM]

The motorhome is only 4 years old and the battery came with the motorhome new

 

[bigtwin]

I’d also be asking what type of ‘drop tester’ was used before I concluded anything about the test results. A conventional tester used for starter batteries is no good for testing leisure batteries.

Ian

 

[ARTPLUM]

I don’t know what kind of drop test they used

 

[donkey]

I would carry out a capacity test on the battery before condemning it. If you are not sure, you will find plenty of know how on the web. Or come back here for more details of how to do it.

Geoff

 

[ARTPLUM]

Can you please give me more information

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[SpeedyDux]

The motorhome is only 4 years old and the battery came with the motorhome new

The build date of the conversion, when the battery was fitted, is more relevant than the DVLA registration date. Your battery could be nearer 5 years old than 4.

 

[DerryW]

That looks like a work bench well used. good on ya. Mines exactly the same, as for the record vice its seen many years of good service, but loathed to replace it.

 

[dunnah01]

Just go off grid with it for a couple of days and don't worry about it - there's lots of other things in that moho to be worried about

 

[Raul]

Why would you drop test a leisure battery? Who in their right mind think that you will need healthy cranking battery in the back?
Drop test is for cranking battery test, not for leisure. The leisure battery will never see cranking use, so it’s not built for that. Of course will never perform a drop test.
Useles ppl.
You can do a capacity test, not a drop test. I guess that takes time and right equipment for logging the results, so they skip and kill the leisure with a jolt of drop test.

 

[Lenny HB]

Can you please give me more information

First charge the battery fully and leave it to settle for an hour then:-

Disconnect all charging methods.

For example if it's a 100a/h battery load it with a 5 amp load and run for 5 hours, this will represent a 25% discharge. (adjust load/time to suit the size of the battery)
Disconnect the load and leave to stand for at least 30 min then measure the voltage.
Repeat the test and you will have discharged the battery to 50%.
You can repeat again then it will be 75% discharged.

Anyone who drop tests a leisure battery obviously hasn't a clue.

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[donkey]

Can you please give me more information

Hi
You will need a multimeter.
First thing make sure the battery is fully charged, then leave to stand for a few hours.
Make a note of the battery voltage and the time.
Place a known value load on the battery of between 5 and 10amps. You could use a headlamp bulb for instance. A 60w bulb will draw 5amps.
Leave the load on and regularly check the battery volts.
When the battery has dropped to 10.5 volts make a note of elapsed time.
To calculate the battery capacity: If you used a 5amp load and it lasted 12hours then the capacity is 5X12=60amp hours. If you used a 10amp load and it lasted 7hours 10X7=70amp hours.
Compare this figure with the stated capacity of the battery and you will have a good indication of its condition.

Geoff

I see Lenny has given you a different regime, while I was battling with my keyboard.

 

[pappajohn]

The motorhome is only 4 years old and the battery came with the motorhome new

Expected life for a lead acid battery used for leisure use is 5 years.
That depends how often it's been discharged below 50% (around 12.2v)

 

[pappajohn]

I don’t know what kind of drop test they used

The drop tester that increases their profit by selling you an overpriced battery.
Cynical ....me!

 

[ARTPLUM]

Thanks to you all for all the information (the battery is a 110Ah battery) for those how are doing the calculations for me

 

[Lenny HB]

Thanks to you all for all the information (the battery is a 110Ah battery) for those how are doing the calculations for me

At 4 years old the capacity will be 99 ah, so use my figures for 100ah.

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[pappajohn]

Anyone who drop tests a leisure battery obviously hasn't a clue.

Now that depends Lenny.
If it's a starter battery in a leisure battery wrapper then quite acceptable.

 

[pappajohn]

At 4 years old the capacity will be 99 ah, so use my figures for 100ah.

Unless it's been deep discharged a few times.

 

[Lenny HB]

Unless it's been deep discharged a few times.

It would be F'all then.

 

[ARTPLUM]

It’s never been deep discharged it’s always been on Eu on sites or in the back garden

 

[PaulOH]

IMHO it depends a great deal on the brand and the use. Today I replaced a (presumably) 80-90ah starter battery (it has no markings on it at all) with a brand new yellow-pack 95ah after owning the van for almost 6 years.

I had to get the leisure battery replaced in 2019 after the charging circuit was validated dead by a garage - not even the 12volt fridge worked by then - and after throwing money at it, everything still works well for the moment - tho I don't know what battery it is.

The starter battery did sterling service for 5 years but got dodgy over the last year. I had always tried to run the van at least a bit to make sure that something was recuperated from each start as they can be few and far between at times, but recently the charge hadn't been holding for long and I had lucky breaks as recently as early-Feb following charge & a drive which later only turned the engine over slowly but it caught in the end - God be with SOFIM!

I intend to repurpose the old battery as an away-from-the-house source for LED garden lights!

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[Lenny HB]

Now that depends Lenny.
If it's a starter battery in a leisure battery wrapper then quite acceptable.

Except he was testing the leisure battery in the habitation area.
Me thinks you are winding me up.

 

[jongood]

.

 

[Pausim]

Would a drop test damage a real leisure battery? I thought that leisure batteries had heavier plates with less surface area so that they can withstand deeper discharge but as a result should not be expected to deliver cranking level Amps.

 

[Raul]

Would a drop test damage a real leisure battery? I thought that leisure batteries had heavier plates with less surface area so that they can withstand deeper discharge but as a result should not be expected to deliver cranking level Amps.

At some extent yes, as you know the starter cranking has thin multiple plates to increases surface are, capable for huge short bursts: cranking. On leisure the C/5 it’s kind of the limit before it start to shed its active material of the plates. This happens, due to excessive discharge rate, several C’s. Well beyond for what was designed to do.