# Leisure Batteries Question



## HikerG (Nov 20, 2009)

Hi,

My 'new to me' motorhome is fitted with a single Exide PP75 Porta Power sealed lead acid 75Ahr leisure battery in a space to the right of the driver's seat. The dimensions of this battery on one website are 278x175x225 high. Firstly the cover does not sit properly because I think the leisure battery is slightly too tall. Now I need to increase my battery power so need to decide on my options. I'm not sure if you could fit 2 batteries in this space, perhaps you could if you turned them the other way, currently the way the securing plate has been fitted there is lots of space around the battery. The is space for a 2nd battery under the dinette seat but not sure how I would connect both batteries together, if indeed doing so is the best way forward.

So I'm left wondering whether it would be better to just replace the one battery with a higher Ahr one that ideally is not so tall or whether I should try and go for 2 leaisure batteries both of a larger Ahr in which case how easy are they to fit?

On a kind of related topic I want to know how others power their laptops when off hookup. My HP dv6 and before it Samsung just do not like any of the options I've bought from Maplins. First I tried the cheap 300W inverter which would charge it ok but would not allow me to actually run the laptop (used to beep at me). So I went back to Maplin and was sold one of these:

http://www.maplin.co.uk/Module.aspx?ModuleNo=226534

I was told these are designed for laptop use but the thing will not even charge the laptop as the green LED light blinks (instructions say green light is solid when working OK and red when not, nothing about blinking).

I know pure sine inverters or whatever they are called are supposed to be great but seems a nonsense to spend more than £500.00 to find a solution. Would be cheaper to buy one of these notebooks with 7 hour battery life for less money or buy additional spare laptop batteries and keep a few charged when I do visit hookup.


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## joedenise (Jul 20, 2007)

Have a look on Outdoor Bits website at the Elecsol batteries. We've found them the best so far and managed to fit 2 into the space where there was previously a large 75aH battery. You'll need to measure your available space and see what batteries you can fit in. All the sizes are on the website.

Can't help with charging the laptop.

Joe


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## JeanLuc (Jan 13, 2007)

Plenty of info on batteries if you search the forums. We have 2 x 110 Ah Elecsol and that will last us 3-4 days in the depths of winter; probably a week in summer.

Regarding the laptop issue, I use an inverter. (Others use a 12V stabilised adapter, but my MacBook Pro needs a DC supply in excess of 16.5V.) You may not need a pure sine-wave model - I have one because I wanted to ensure I could power any loads. You do not need a large inverter for a laptop or other small appliances - our is 150W and cost about £85. They have since gone up to about £100.
The problem you experienced with the inverter beeping was most probably caused by voltage drop in the cables supplying 12V to the inverter. This is a common problem and is cured by connecting the inverter directly to the battery with very thick cable - via a fuse of course.

If you want to see how I tackled the problem, go to the downloads section and get a paper entitled "Installing a small inverter".

Philip


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## wilse (Aug 10, 2007)

Gary

Just a couple of thoughts.

Elecsols are good batteries, we've 2 x 100amp. wired + to + and - to -.
In our old truck we had a 300w inverter. When the laptop was on there was no chance of it operating form the inverter. If It was closed it would charge the inverter.

I would also suggest that you have thick cabling from batterie to inverter.
Thinner cable can give a voltage drop that won't supply enough volts for your inverter.

Clive Mott is your man to search for RE wiring & batteries.

w


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## Dopfer (Aug 16, 2009)

To power my laptop I use a Universal DC adaptor, running off the 12v supply, it will power up and charge at the same time. It automatically senses the voltage of the laptop. They come in various wattage outputs, the one I use is 90 watts DC output. My laptop requires 19v at 3.4A. this one cost me £25 off Fleabay


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## gaspode (May 9, 2005)

It sounds to me as if you're battery is completely knackered.

The 300w inverter should power and charge your laptop with oodles of spare capacity. But why use an inverter? First you're changing 12v DC to 230v AC, then back to 20v DC again via the laptop power supply with every power change losing a fair amount of efficiency. What you need is a DC to DC converter like this one:
http://www.maplin.co.uk/Module.aspx?ModuleNo=44736
Check the output plugs first though, HP laptops can have some very odd power sockets. :roll:

Chances are that if you just fit a new battery - any new battery - you'll sort the problem.


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## jhelm (Feb 9, 2008)

I was advised by the local auto electrical shop which seems to always have a camper getting something done to just go with a normal battery around 100 amps. They perform as well as the "camper" batteries cost 1/3 the amount and last nearly as long. So far we have been happy with that choice.


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## CliveMott (Mar 10, 2008)

Be a little wary when a Laptop causes a 300 watt inverter to stop or not start if the Laptop is connected first.
I too have found that SOME laptop power supplies rely on the mains being sinusoidal to limit inrush current to the initial smoothing capacitors within the laptop power supply. One Laptop sample was brought to me to look at because the laptop caused their inverter to stop. I tried it on the mains and it was fine, then my spare nearly new 300 watt Maplins inverter and the inverter stopped. I tried several times and whatever way I tried the two were not compatible. Eventually with the laptop connected I flicked the ON/OFF switch on the inverter several times until a whisp of smoke came out the inverter and its fuse blew.
I put the inverter in the bin.

My older Toshiba Laptops always worked fine off this inverter, but not this one from Panasonic.

Expensive learning curve for me!

C.


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## Manchego (Sep 26, 2009)

I use a Sterling Pro Power Q 350W inverter to charge my MacBook. It has the magsafe connector and despite frequent searches have not yet found a suitable alternative charger. If anyone can suggest a better way please do so.


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## HikerG (Nov 20, 2009)

Hi,

Well took the mini inverter back to Maplins and exchanged for one of the laptop power supplies which had the connector for my HP laptop amongst others. Has adjustable voltage selection and at 18v works perfectly from the cigar lighter socket. At the same time I bought a connector that goes from Hella type plug (which is what my motorhome seems to have in habitation area) to 2 cigar type connectors. 

I can confirm there is nothing wrong with my battery. The 300W maplin invertor I used to have did not work on any battery I tried it on. Sometimes it would run for 5 minutes before the alarm signal but was next to useless plugged into cigar socket. It would charge things like mobiles and AA batteries though so I know laptops must just be more fussy. Certainly did not want to wire directly to battery using thick cables just yet until I find I need lots more electrical devices whilst off hookup which I hope I won't.

As for the leisure batteries, thanks for the heads up about Elecsol. The 100AHr model is the same width and length as my current 75AHr but slightly shorter which is great news. Will have to see if I can fit 2 in side by side by turning the other way. If not could always buy just one 110Ahr for now as that would fit right in. 

Thanks again for advice. 

Gary


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