# Fitting an extra leisure battery.



## plumbill (May 6, 2006)

Hello Folks. Its me again "Plumbill" 
I have installed two brand new 110ah leisure batteries into my Motorhome. my motorhome is a 2008 Autotrail Arapaho. The loom that the manafacturers use to take the power to the system with, has a plug sitting adjacent to the battery to connect a second battery to the system when you purchase the extra piece of loom to connect up the second battery. There is no problem with that part of it . Now. I am installing a 2000watt inverter under the seat compartment in the dining area and what I want to know is, although the both batteries are linked together with the proper looms ,can I also join the batteries together with a fairly stout cable in order to take the power to the inverter with out any problems. Thanks for your help Willie.


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## Vennwood (Feb 4, 2007)

Hi Plumbill,

I'm not familiar with the Arapaho setup so can't really coment on the Loom bit. Presumably this is of a fairly stout cable also? or is it just for recharging and light loads?

Anyway there is no problem with joining the two together with a decent pair of cables so long as you make sure you connect them up in parallel(positive to positive etc.) then connect up the inverter as normal.

Pete


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## DJP (May 9, 2005)

Hi Plumbill, 
I have 3 x 110amp batteries in my Chieftain and a 1000w inverter in the locker. I have just connected the inverter to the centre battery using the "welding" type cable supplied with the inverter. The other 2 batteries are connected in parallel. everytning works ok.
I would however question the use of a 2000w inverter.
1. The leisure batteries will not last long if the inverter is used at any where near full power. 2000w = approx 160 amps and as you should not really use below 60% of the battery charge, they will be flat in less than an hour. Even using the 2000w to run a Tv/Sky box/laptop is a bit over kill and will use more power to run them than a smaller, but powerful enough inverter. I have just purchased 2 x 150w to replace the 1000w. ! will run Tv and Sky box with reserve. The other will run Laptop and printer.

I am sure Dave will be along shortly with his opinion and what he says GOES!
Dennis


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## Vennwood (Feb 4, 2007)

Hi Dennis,

I have a 2500w inverter and use it for all sorts of things - kettle (low watt), microwave, toaster etc. We never have them on all at once and not for long either. For example the kettle, 950w is on for approx 4 mins and takes around 5 amps. So IMHO I think a 2000w inverter is sensible as you have a little extra amps in hand just in case. I would say though that a battery monitor/management system is a good thing to have as you can see exactly what you have taken out of the batteries or put back for that matter.


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## DJP (May 9, 2005)

Hi Vennwood
I accept what you say, an odd boil of the kettle use 5 amps, which is not a lot. Go away for 5 days have 5 brews a day and use nothing else, lights, tv, laptop, warm air heating (now that does sap the power) that's 125 amps gone and so are your batteries. (Assuming van is static and no solar panel/wind generator.
A big inverter is fine, but you do have to be very careful with usage. If you do need to power a kettle or use the microwave, then use it. If you want to run a TV/Laptop or small appliance the consider a smaller inverter as well.
This is what I have found. We are ditching the 1000w and the microwave and using gas for the brews and cooking.

Anyone want to buy a 1000w Ring inverter with remote switch? :lol:


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## Vennwood (Feb 4, 2007)

Hi Dennis,

I agree - its all about set up and common sense. We have solar panels and a genny and the Sterling battery management system which is brilliant. I can tell what's in the batteries at any time and the inverter would cut out if the batteries get low. I wired in 4 seperate sockets for kitchen, Microwave, Hair drier in bathroom and one for the lounge. We have never found it a problem and use the kettle, coffee maker and microwave all the time to save on gas. Our solar panels keep the batteries topped up so its all free for us. In 20 weeks away this year, mainly wild camping or on Aires in France we used the genny once - and that was because we parked under trees at Trebes for almost a week and when we moved on it was cloudy and rain so I used the genny to top up just in case. All other times the solar panels had fully recharged the batteries before midday. We didn't use EHU once.

One inverter is simpler to manage than several and with a remote control its easy to switch on/off


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## CliveMott (Mar 10, 2008)

If you are running a 1000 watt or even a 2000 watt inverter the you must connect all the batteries in parallel with 25 sq mm or even 35 sq mm welding cable. POS to POS and NEG to NEG. This will encourage the batteries to share the load. If you dont use thick cables to all the batteries then there is a risk of the smaller paralleling leads catching on fire.
The 2000 watt inverter at full output will consume about the same as your starter motor!. At least 170 amps ish and more as the battery voltage falls under load.

http://www.motts.dsl.pipex.com/second leisiure battery.htm

C.


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## 117306 (Oct 9, 2008)

Hi
I'm also thinking of adding another 120 amp in parallel to my existing 120amp battery. Can anyone advise where I can get a larger battery box to fit under the floor in place of my existing one? 
Thanks in anticipation.

Dave


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## plumbill (May 6, 2006)

*leisure batteries*

Hello Clive. I will be connecting the 2 batteries together with the same thickness of cable for the inverter to run off, however will the manufacturers loom to the 12v lighting system connected to both batteries be safe from the risk of fire. The 2 new batteries I have bought have double connection poles at each side P and N. so the connections for the inverter will be simple enough if you can understand what im saying. Willie. (Plumbill)


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## Sargent (Feb 1, 2008)

*Battery Wiring*

Hi Plumbill,

All great advice in the above posts, the batteries are indeed already connected in parallel but as clive has said connect them together using large size cabling to match the maximum draw from the inverter.

Depending on what you will use the inverter for a 2KW maybe a slight overkill, you'll probably never use even half of its capabilities. The best advice I can give you is to keep an eye on your battery levels when using your inverter as they are known for sucking the life out them very quickly.

Best Regards

Karl Hulse
Sargent Electrical Services Ltd


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## plumbill (May 6, 2006)

*Leisure batteries.*

Thanks a lot to everyone who subscribed to the information I needed for this job. It is completed now with no problems so far. :lol: :lol: Plumbill.


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## Pudsey_Bear (Sep 25, 2008)

Hi Clive,

I just followed your link, and was curious to know why you reccomended two 6 volt batteries, why is this please.

Cheers Kev


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## DABurleigh (May 9, 2005)

Because just two 6V batteries connected in series means both batteries experience identical charging and discharging currents, so life is maximised. With two 12V in parallel, life for both can be curtailed due to minor differences between them meaning different currents.

Dave


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## CliveMott (Mar 10, 2008)

The kid learns fast!
C.


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## DABurleigh (May 9, 2005)

Thanks Grandad!

You owe me 3 weeks' pocket money btw ...


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## Pudsey_Bear (Sep 25, 2008)

*Leisure batteries.*

Thanks for that Dave,

Very well explained, so would 4 x 6v be better than 2 x 12v?

While were on 6v, I assume that they are smaller and so might lend themselves to fitting in places where 12vwon't go, but has the technology kept up with 12v or are they in front.

Cheers Kev.


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