# Battery charger - advice please



## asprn (Feb 10, 2006)

Our van goes into dry storage over the weekend until January. It has 4 x beefy leisure batteries plus the engine battery. I suspect the leisure batteries will not have much life left in them as they were new in November 2006 and now tend to lose charge more quickly than they have done, so I may replace them next year.

I will isolate all the batteries (coach & chassis) from inside the van, but want to leave all of them on a top-up charge. I understand that the "normal" car battery charger I have, isn't the right sort, and that I need one which effectively works like a thermostat - it only cuts in when the charge drops below a certain level. So my questions are:-

a) is my understanding correct, and if so,
b) what charger should I get, and 
c) what's to stop me linking all five batteries together (even although one is a normal vehicle battery and four are leisure) so the charger will top-up all of them as & when needed?

Thanks,

Dougie.


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## Sprinta (Sep 15, 2010)

my understanding is that to trickle charge 5 batteries at once from one charger will not be possible as each battery will have its own 'need' for charge rate and will not charge correctly. Ideally you'd need 5 chargers , one for each.


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## raynipper (Aug 4, 2008)

I was able to buy a couple of those fit and forget type chargers Dougie from Lidl a couple of years ago at €17 each.

I personally don't need them on the van as it has it's own top up charging system. 

Again personally leaving your rig in store for that length of time, disconnect all batteries, fully charge and then hope for the best.
Those that make it over the time will be kept and those that don't are obviously on their way out.

Ray.


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## cater_racer (May 1, 2005)

You can trickle charge all the batteries off a single battery maintainer type charger.

PROVIDED THEY ARE ALL IN FAIRLY GOOD CONDITION.

You need to stop the better charged batteries draining into the lesser charged ones, you can do this by a simple diode placed in the charge feed.

http://www.maplin.co.uk/3a-silicon-rectifiers-46405

Will do fine, start by making sure that all the batteries are in decent condition and voltages are similar. The battery conditioner should limit current to around 1-2 amperes, the diodes will ensure no circulating currents occur.

HTH


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## CliveMott (Mar 10, 2008)

The diodes will also drop 0.6 volt to every battery which is significant.

I would simply parallel the lot with some fuses and leave a small CTEK intelligent charger maintaining them as a bank. NO DIODES.

C.


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## asprn (Feb 10, 2006)

So - to diode or not to diode? That is the question. 

As I'm fairly sure I'll be replacing the leisure batteries next year, I'll opt for no diodes. The chassis battery is only a year old and is pretty standard.

Is >> this the one << I should be getting?

Thanks,

Dougie.


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## peedee (May 10, 2005)

Why not simply remove the batteries and store at home where you can keep and eye on them and charge and top up each individually as necessary?

I have had one in my garage now for 3 years and give it a top up with a Halfords battery charger about every three/four months.

peedee


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## PeteandMe (Sep 19, 2010)

If your fairly sure that you are going to replace them why not scrap the duff ones. Keep what you think are good. Use the money from the scrap batteries to buy the charger and save on the cost of electricity.


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## trevorf (May 16, 2005)

> Is >> this the one << I should be getting?


Yes Dougie, that one will do fine. There are other more expensive models of CTEK with higher outputs for faster charging, but if its just maintaining your batteries over a storage period then that one will do the job.

Trevor


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## asprn (Feb 10, 2006)

peedee said:


> Why not simply remove the batteries and store at home where you can keep and eye on them and charge and top up each individually as necessary?


Because the reason we're storing the van here is we're off to the States & Canada to tour. The electricity is also included in the storage.

Thanks,

Dougie.


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## andrewball1000 (Oct 16, 2009)

Whatever charger you get you might also consider a timer. 

I use two leisure batteries on an electric canoe. I have stored these in the garage for over four years now. I have a charger that will maintain at Float, but I didn't want to leave it on all the time so I connected a timer that comes on for 2hrs a week. They are fine and I dont have to worry about cooking them or the charger failing.


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## cabby (May 14, 2005)

If I were away for that length of time, I would disconnect all the batteries, unattended charging over 6 months, you cannot be serious. :roll: :roll: 
the batteries with anything left in them will be kept I assume and replace others, as you say they are on their way out.

'elf and safety rears it's ugly head again. :wink: :wink: 

cabby

edit. will your insurance cover you on that. 8O 8O


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## CliveMott (Mar 10, 2008)

Yes, that CTEK will do the job but as has been suggested a higher rated one could be more usefull for other duties. The CTEK chargers do go through several charge stages and end up (after fully charging the batteries) with a lowish maintaining voltage which can be left on continuously. No need for a timer. Just make sure that your insurance covers the van in storage and hooked up. Just in case.

Enjoy the States.

C.


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