Battery size?

[gaza101]

Hi everyone
Dealer is fitting a new motor mover to our recently purchased van. ( Unicorn Valencia 3)
He says a 100amp battery is sufficient. Does this sound right?

Thx

 

[ProfJohnL]

Absolutely it should be. -

 

[Kevin M]

We have an 80amp fitted and never had an issue.

Kev

 

[RogerL]

In practice, it depends how far the mover needs to be used and whether there's significant gradient - it also depends whether the battery is also used for off-grid caravanning.

I used to use an ancient 70 Ah car battery with no mover issues - but all sites had EHU so the battery was only used for the mover.

 

[bertieboy1]

Hi everyone
Dealer is fitting a new motor mover to our recently purchased van. ( Unicorn Valencia 3)
He says a 100amp battery is sufficient. Does this sound right?

Thx

When you say "a 100 Amp" battery do you mean 100Ah ?
Assuming you do - motor movers don't use that many ampere hours,depends on how long they are running.Just multiply the motor mover running current by the time it runs,this will give you ampere hours. eg. if mover running current is 60 Amps and you run it for 10 minutes this equals 60 times 10/60 = 60A times 0.16 hours = 9.6Ah so a fully charged battery is only discharged approx 10 %
Check this for yourself and decide if battery is OK - I would say it is.

 

[RogerL]

When you say "a 100 Amp" battery do you mean 100Ah ?
Assuming you do - motor movers don't use that many ampere hours,depends on how long they are running.Just multiply the motor mover running current by the time it runs,this will give you ampere hours. eg. if mover running current is 60 Amps and you run it for 10 minutes this equals 60 times 10/60 = 60A times 0.16 hours = 9.6Ah so a fully charged battery is only discharged approx 10 %
Check this for yourself and decide if battery is OK - I would say it is.

It's not just about the battery capacity - it's about how many amps the battery can deliver repeatedly without significant internal damage - a 10 Ah battery could deliver the energy for the mover but would be irrecoverably damaged internally.

 

[WayneS]

When we bought our van a few yrs back - it didn't have a mover, did have a lower capacity battery (I think 70AH) bought and had fitted secondhand mover - battery was more than adequate to put the caravan on a pitch- doesn't take long or that much power. After buying a defective one, I replaced it with a slightly higher capacity but only 85AH - just because i found one which was cheap & the old one was not holding charge any more: 100AH I'm sure will serve you very well!

 

[ProfJohnL]

When you say "a 100 Amp" battery do you mean 100Ah ?
Assuming you do - motor movers don't use that many ampere hours,depends on how long they are running.Just multiply the motor mover running current by the time it runs,this will give you ampere hours. eg. if mover running current is 60 Amps and you run it for 10 minutes this equals 60 times 10/60 = 60A times 0.16 hours = 9.6Ah so a fully charged battery is only discharged approx 10 %
Check this for yourself and decide if battery is OK - I would say it is.

Whilst Bertieboy's maths are correct, he has not allowed for the fact that electric motors reduce the current they use as the motors spin up. Caravan movers use significantly less than half the peak current once they are moving, and in practice the length of time the mover is actually used to position a caravan is typically less than 3 minutes motor running time. This all equates to the total charge usage of typically less than 2Ah.

All good news

 

[gaza101]

Thanks for all your replys. I did think it sounded OK but sometimes brain goes into overdrive. I never thought I'd need a mover but watched a few on YouTube and it looks doddle. The mover is swaying me to park on my drive rather than storage so I wouldn't want it to stop while putting it away or getting it out.

 

[JTQ]

The underlying important bit is keeping a healthy battery, as shown a 100 Ah battery is of way large enough capacity to do any realistic mover duty, but only whilst it has tolerably good health. ie still supply the requisite current without undue voltage drop.

I suspect the industry's and many users' enthusiasm for large capacity batteries for mover applications lies solely with their better tolerance to still "work" into "sickness"; a knackered 110 Ah doing a better job than a similarly knackered state 60 Ah battery.

 

[Hutch]

I had an 100 amp/hr battery on a 1645 kg Coachman, with a Power touch MM. I had to move pitch and the battery coped with moving the van about 50 yards to the new pitch and then wiggling about, with no problems.

 

[Woodentop]

One point, one suggestion.
The point: remember that car batteries are rated at C/10 whereas caravan batteries are rated C/20. Probably won't make any difference here but bare it in mind.
The suggestion: Contact the mover manufacturer and seek their advice.

 

[otherclive]

One point, one suggestion.
The point: remember that car batteries are rated at C/10 whereas caravan batteries are rated C/20. Probably won't make any difference here but bare it in mind.
The suggestion: Contact the mover manufacturer and seek their advice.

C10,C20 what’s the code for this rating description?

 

[Beachball]

Just been to the caravan we have a 85 AH and that copes with our motor mover on our caravan so 100AH should serve you well

 

[ProfJohnL]

For what its worth, When Carver first introduced the caravan mover, it demonstrated it at the caravan show on a part loaded chassis. It was demonstrated with the motors running for about 5 min, Over the period of each 10 hour day it would have been running for roughly 200 minutes and it was all done using 110Ah battery. A freshly charged battery was fitted each day.

 

[JTQ]

C10,C20 what’s the code for this rating description?

Battery's C Rating Explained By SolarKobo

Also, there are related issues with some of the higher quality "real" deep cycling batteries that the motor mover's current draw is above the best practice for the technology used in those very low current draw batteries.
Our van has one, a specific GEL type, where such high draw off that might be encountered is at best, "not good practice". So for the hard work duty I need our mover for I use a small capacity portable traction battery that lives at home on a CTEK, just being used to lug the van out and then back into its car port, a quite demanding climb either way. Just saves abusing the van's battery, where in our case the one used is designed for low current off grid use, not load lugging.
For what is typically a much lighter duty, rolling onto a pitch say, I do use the van's battery, just I don't at home where things are different and the option to avoid it is available.

 

[otherclive]

Battery's C Rating Explained By SolarKobo

Also, there are related issues with some of the higher quality "real" deep cycling batteries that the motor mover's current draw is above the best practice for the technology used in those very low current draw batteries.
Our van has one, a specific GEL type, where such high draw off that might be encountered is at best, "not good practice". So for the hard work duty I need our mover for I use a small capacity portable traction battery that lives at home on a CTEK, just being used to lug the van out and then back into its car port, a quite demanding climb either way. Just saves abusing the van's battery, where in our case the one used is designed for low current off grid use, not load lugging.
For what is typically a much lighter duty, rolling onto a pitch say, I do use the van's battery, just I don't at home where things are different and the option to avoid it is available.

Thanks. It is irritating when posts just include an acronym or jargon, without even an attempt to explain to other readers.

 

[JTQ]

Thanks. It is irritating when posts just include an acronym or jargon, without even an attempt to explain to other readers.

It is though a very universal specification feature of LA batteries in particular, and the Ah rating is quite pointless if not referenced to a specific C value; or maybe I have simply been involved with these batteries too long!

 

[Raywood]

The 100 AH one should be strong enough although leisure batteries should also carry a grading A< B or C.
A is for heavy use by people going off grid, B is for heavier use including movers and C is for use on hook ups.

 

[JTQ]

The 100 AH one should be strong enough although leisure batteries should also carry a grading A< B or C.
A is for heavy use by people going off grid, B is for heavier use including movers and C is for use on hook ups.

Quite different though to the industry Coulomb’s Law based "C" ratings.
Another example of the NCC simply throwing in another level of confusion, the more so in it not being "standard tested" but just the battery brand holder allowed to self credit their product with any NCC usage rating they like. If ever there was "buyer beware".

 

[bertieboy1]

Whilst Bertieboy's maths are correct, he has not allowed for the fact that electric motors reduce the current they use as the motors spin up. Caravan movers use significantly less than half the peak current once they are moving, and in practice the length of time the mover is actually used to position a caravan is typically less than 3 minutes motor running time. This all equates to the total charge usage of typically less than 2Ah.

All good news

You'll note figures are not exact and are only used to illustrate the example,also the current used is "running" current not startup/instantaneous current

 

[ProfJohnL]

...also the current used is "running" current not startup/instantaneous current

That does not agree with my professional experience in the field. The vast majority of running currents are far less than 60A

 

[bertieboy1]

That does not agree with my professional experience in the field. The vast majority of running currents are far less than 60A

It's only an example.