Battery charger while on mains Forums

deadl0ck

Hi all. When you plug into mains, should you leave your leisure battery charger on all the time? The reason i ask is that it buzzes all the time when we are on mains. Just wondering what people do...

cabby

we had one that did that on our Mustang, they changed it for us.or it could just be a relay.

cabby

deadl0ck

Do 12v battery chargers usually make a buzzing noise? My dad had one years ago that always buzzed. I thought it was pretty normal...

EJB

They shouldn't buzz, or at least you shouldn't hear them although they may make some noise...similar to a fluorescent light Smile

safariboy

All battery chargers are not the same. Modern 3 or 4 step chargers will effectively switch off when the battery is fully charged but older (simpler) designs will trickle charge even when the battery voltage is 13.8V. The result is that the electrolyte is decomposed to hydrogen and oxygen and you need to keep topping up with pure (distilled) water.
If possible the best plan might be to charge about once a month for a few hours provided there is no drain on the battery.
The buzz probably indicates that there is a current flowing an so the battery is being trickle charged.

DABurleigh

13.8V is a safe non-gassing terminal voltage. So if that's the voltage after a charge with it still switched on, you are not harming your battery.

As to a buzz (more a hum?) this depends on whether your charger has a transformer in it, and its quality. The hum comes from eddy current in the laminations of the core.

Dave

deadl0ck

It's more of an issue when we are at a campsite and we're plugged into the mains. Then the buzz is constantly there. It's most noticeable at night when you go to bed. Could it damage the battery if it constantly charges? How can i check if trickle charges?

deadl0ck

Thanks Dave. You answered my questions while i was typing them Smile

There is an on/off switch on the charger itself in the MH. Would it be ok to turn off the charger at night while still plugged into the mains?

blackbirdbiker

Sounds like a transformer is noisy, we used to put laquer spray on the windings, mostly it worked but not always, so a replacement may be required.

Keith

DABurleigh

Yes just turn it off at night. Or have another nightcap or two Smile