how to check battery charger is working -separate to caravan

[Robtel]

Hi,
I have a Gunson automatic 12v battery charger allegedly suitable for use on all 12v batteries including leisure batteries. It's not new I've had it a good few years. The question is how do I check if it is working as I have a feeling it has given up the ghost on me.
Connect to battery, set to auto on and 100% charge as per instructions and as I've always done, the needle on the guage doesn't even flicker. It should, and used to, rise to even quarter or half way up the dial, between 3 and 5 then quickly fall back towards zero depending on how much of a charge the battery needed. Changed the fuse in the plug and that is about the extent of my knowledge with chargers.
Should I be able to get a reading with a multimeter from the charger connections when off the battery? Battery reading 12.6 before going on charger, same reading when on the charger.
Shopping for a new charger over the weekend is it? and if so what do you recommend?
I've seen some recommendations for the model from either Aldi or Lidl but you never know when they are going to be available.

Thanks
Robert

 

[JTQ]

Assuming your meter is half telling the truth the 12.6 when "on charge" clearly indicates the charger is not working.
A fully charged and rested battery will give higher than 12.7 volts and on charge be between 13.8 and possibly just over 15 volts [ as it is a old charger for old technology batteries it probably has a 14.1 to 14.4 upper limit]
As you are not seeing 13.8 or more then its not working. If it was then with the 12.6 volts it would get itself into action. Even if it was sophisticated enough to feature a total off charge phase it would when seeing 12.6 volts know it needs to be charging..

The Aldi and Lidl offerings are quite acceptable but as you say spasmodically available. A CTEK 5 amp unit would be an excellent choice but at about three times the budget produces price.

 

[Robtel]

Thanks JTQ, I did think the charger was finished,no shame to it though had it for ages. My existing leisure battery is also playing up on me ( it is Friday 13th isn't it) so I bought new one, got a Numax 110ah delivered from Tanya this morning. Excellent service by the way, only ordered it yesterday afternoon. Thought I would put it on the charger before putting it out in the van, that' when I found out the charger was out in sympaty with the old battery. There is a whole pile of ctek chargers, had a look at a 5 amp unit as you suggested,
this one:
http://www.amazon.co.uk/CTEK-CTE-MXS5-0-12V-Battery-Charger/dp/B004ZWV1JI/ref=sr_1_1?s=automotive&ie=UTF8&qid=1379085887&sr=1-1&keywords=ctek+5+amp

In product description it makes no mention of leisure battery, only car battery as far as I could see. Would that be a problem? or would it do the job
Thanks
Rob

 

[JTQ]

It will do the job exceedingly well.
Leisure batteries dont require differing charging routines to starter batteries only lower rates of recharging and sub 5% of your battery size, or even up to about 9% is just what you need for Leisure batteries.
Differing battery technologies, such as "sealed" or "flooded" benefit from differing charge routines. As nearly all modern batteries are now "sealed" the CTEK is ideal.
It is better than the Aldi Lidl offerings in that it has a memory so you dont need to do anything if there is a power outage; when power is restored it sorts itself out. Therefore you can leave it on unattended as long as you like but that cost a wee bit more in power than say recharging every few weeks. All mine are left on charge ready for use. I even clip one on the wifes car when we are away for a week or more.

 

[Robtel]

Thanks for your help

 

[ChrisUK]

Seems like the charger is duff, but I would be useful to check for fuses.
I have used a Lydl charger for some years and it has been very good, I can definitely recommend them. However, being a bit flush earlier this year I did buy a C-Tek MXS 5 which costs about three or four times the price of a Lydl Aldi, I did it because I wanted to use it on my modern car without disconnecting the battery from the car, something that C Tek say you can do, it has a slightly bigger output 5 amps instead of I think 3.6, and if there is a power cut you don't have to reset it. The MXS also gives you a better idea where its at in the charging cycle.
I have still got my old Halfords Automatic charger from about the same vintage as yours, but chargers are far more sophisticated now.

 

[Robtel]

A CTEK 5 amp unit would be an excellent choice but at about three times the budget produces price.

Followed your advice and bought a CTEK 5amp, must admit to being favourably impressed with it in comparison to my old Gunson. Only thing is my old leisure battery,reckon it must be about 7 years old which I thought was kaput has been revived to apparent full health by the recondition facility on the CTEK. Wouldn't mind so much if I hadn't bought a brand new Numax a couple of weeks ago to repllace aforementioned "kaput" battery. Never mind now have a spare, To be fair at 7 year old I don't know how much longer it would have lasted anyway.
Thanks for advice, would now agree with your recommendation of the CTEK 5amp

 

[RogerL]

As nearly all modern batteries are now "sealed".

A triumph of marketing over fact.
Generally, car and leisure batteries are not sealed, they just have a sticky label over the cell caps !
A few, higher priced, leisure batteries are built with no cell caps, just a pressure-release valve.
Proper sealed valve regulated lead acid batteries (VRLA) aren't cheap.