People get confused regarding the AH (amp hours) of a battery thinking that the larger is more powerful which couldn't be further from the truth. The only difference is the amount of hours the battery will provide so theoretically a 75 ah. battery should provide 75 hours of 12 volt power and a 110 ah. giving 110 hours of 12 volt power.
However, the mover will only be used for a few minutes so there should be no concerns if you are connecting up to a mains hook up supply straight away to replenish the power used from the onboard charger. It's only if you are going on site with no mains power such as a rally field and totally reliant on solar panel energy that should raise any concerns of how much power the motor mover will consume before being able to replenish by a small charge.
Nothing I would disagree with there Tango. It's more about capacity than power. A 12 volt battery is a 12 volt battery, regardless of its capacity (ah), but I would rather have capacity I rarely need rather than not enough. A 110ah battery is no more powerful than a 75ah battery, but it can deliver that power for longer, if necessary, which most of the time it probably isn't.
------------- Best Regards,
Colin
Discounted Insurance Quotes for UKCampsite.co.uk visitors! Up to 12.5% off!
Tango spot on.. Hence my 18Ah jumpstart battery working the mover for quite a while.
My specs state 120Amps MAX, That will be a very steep climb, maybe a kerb etc. Average consumption is 20Amps per motor.
Colin21, your sort of right but missing the point where AH rating is useless if the battery cannot provide the amperage.
Your right a 110Ah battery maybe no more powerful than a 75Ah battery and the opposite maybe true. It depends on the batteries construction.
Slight OTT but just to give an example. My 18Ah battery will have thick internal plates and connections to allow 400amps to pass without dropping the voltage.
Now Mr ripoff battery maker thinks right this is a leisure battery i will save money by using plates half as thick and connections only suitable for carrying 10amps.
In most situations this battery will work fine, although it will get hotter when undeer load of more than 10amps and being charged at more than 10 amps. But most users wont notice.
So the battery quality plays a big part. I have my doubts about these cheaper caravan batteries. And my next new one will get tested before actual use.
I did a test a while back. Ran a car battery with an inverter and a 100w bulb. Worse combination with the inefficient inverter. I forget the figures but was approx 140 watts at the battery terminals. So a little short of 12amps. After a couple of hours the battery voltage had dropped to below 12v.
I repeated the test with a much smaller car battery 60Ah? and after 4.5 hours the voltage was still above 12.2v, maybe 12.4? I did post the actual figures a while ago so they are from memory but fairly accurate.
Someone mentioned a website recently where they tested leisure batteries and found oner brand to be less than 33% of its rated capacity, several brands around half and only 1 or 2 near the correct figure.
They wouldn't name brands though.
Im thinking that all those years of saying not to use a car battery may have been poor advice. Or maybe only relevant back then?
Maybe just recent years as they wanted to push prices down?
a batteries capacity is measured over a 20 hour discharge.. the higher the discharge the lower the capacity..
a 100ah battery when fully charged and new should be able to deliver a 5 amp load for twenty hours before going flat or a 1 amp for 100 hours..
a good condition 75ah is ample to power a motor mover assuming that is all the battery is used for..
if the van goes straight on a hook up a car battery would do the job.. leisure batteries are "deep cycle" batteries car batteries are not but powering a motor mover for a few minutes isnt really a deep cycle for something like a 75ah battery..
a car battery may well bang out 400 amps or so for a few seconds to start a car engine but its only about a 2 or 3 percent discharge the battery then gets topped up.. the discharge/charge cycle is a very shallow one..
how good the average so called leisure battery is i havnt a clue but if it wont passed the 20 hour capacity test it would be false advertising..
the good point here is that very few caravanners ever deep cycle their leisure batteries.. running a mover for few minutes and then going on a hook up isnt a deep cycling thats for sure..
purely a guess here but assuming the average mover consumption to be 40 amps i dont think it is as high as that but allowing for some losses a good 75ah battery should power a mover for about 1.5 hours of solid use.. five minutes is more the norm.. :)
motor movers use mobility scooter motors.. the caravan may well be heavier but it dosnt move as fast or for as long.. he he..
It maybe false advertising but how many have the equipment to test it properly and what percentage of those have ever thought to check it?
If someone does check it, they will just say you must have a dud one. Heres another one which is taken from the good pile not the make it as cheap as possible pile. Or just say it was a bad batch have a refund.
I use a Lucas AGM leisure battery. Mainly due to the fact my brother had an AGM battery sat in his garage for 9 years and it still held charge perfectly. I used it for 3 years and I always camp off grid using an 80 watt solar panel. I damaged it beyond repair by dragging it down the road for 5 miles ( another story) and wore 3 inches off the battery. Amazingly it still worked and powered everything on my caravan for the final 36 hours of my holiday. Quite a glowing endorsement I thought.
So on my return home I bought a Lucas 105ah AGM for £150 and it's been perfect for 4 years now.
I know this doesn't answer the OP question but I thought it was worthy of a mention while on the subject of batteries.
------------- La Plage Blanche
Camping Solitaire Du lac
Camping Les Bouleaux
Val de Vesle
Quote: Originally posted by jtaw45 on 08/8/2017
I use a Lucas AGM leisure battery. Mainly due to the fact my brother had an AGM battery sat in his garage for 9 years and it still held charge perfectly. I used it for 3 years and I always camp off grid using an 80 watt solar panel. I damaged it beyond repair by dragging it down the road for 5 miles ( another story) and wore 3 inches off the battery. Amazingly it still worked and powered everything on my caravan for the final 36 hours of my holiday. Quite a glowing endorsement I thought.
So on my return home I bought a Lucas 105ah AGM for £150 and it's been perfect for 4 years now.
I know this doesn't answer the OP question but I thought it was worthy of a mention while on the subject of batteries.
It may not have answered my original question, but it's an interesting point anyway.
As it happens, I have now bought a conventional 110ah battery. It was marketed as a leisure battery, which it may or may not be, but I'm sure it will do the job.
Quote: Originally posted by trog100 on 08/8/2017
interestingly we have two confusing examples.. £150 quid for a Lucas 105ah AGM battery and around £75 for my 110ah cheapo type leisure battery..
my cheapo as now had three years of mostly off grid use and is still going strong..
if i put my fancy battery tester on my cheapo battery it tells me its 80% of its as new capacity or like a new 85ah battery..
i would give it another couple of years before its down to 50% of its as new condition then it would be time to replace it..
the mistake people make is to think batteries just fail.. in the end they do but long before that they simply wear out and lose capacity..
i dont doubt that the £150 quid battery would last longer than my £75 quid battery but then again it does cost twice the price..
battery capacity is a bit like the tread depth on a tyre.. the more you start off with the longer it will last before its worn out..
i dont buy "expensive" batteries because i dont think they are good value for money but i do buy as big a battery as will fit into the space i have..
the only real down side to a bigger capacity battery is it weighs more.. it has more lead in its pencil so to speak..
trog
I fully agree Trog and only time will tell. I sell batteries and car parts and accessories for a living so am well placed to make an informed decision. Wether i'm right or not remains to be seen.
I think the main factor with longevity of a lead/acid battery is how it's looked after. I've seen many just put away in storage over winter and not charged for 4 or 5 months which kills them.
------------- La Plage Blanche
Camping Solitaire Du lac
Camping Les Bouleaux
Val de Vesle
one thing that will kill a lead acid battery is to let it go dead flat and leave it that way for a relatively short time.. left flat for two or three weeks can totally kill it..
a hard sulphate layer builds up on the plates and the battery refuses to take a charge once that happens..
car alarms or anything that slowly discharge a battery to a dead flat state over time will kill them.. a good battery will stand for long time without reaching a dead flat state but once that state is reached leaving the battery like that will kill it very quickly..
lead acid batteries wear out (with use) in two ways..
one is that some of the plate material ends up on the floor of the battery case.. the other is the hard sulphate level on the plates slowly builds up..
most people continue to use a battery well past its accepted wear out point.. a commonly accepted wear out point is 50% of as new.. at this point the battery will still work but it should really be replaced..
at a rough guess i would say most of the lead acid batteries in use are past their wear out state.. people just tend to keep using them until they die completely..
one thing i do wonder about is allowing for the fact that we are so dependent on battery powered stuff in this day and age.. is just how little the average user knows about them and how they work.. :)