trickle charger confusion???

bought a trickle charger yesterday for when the wife's 'F goes into hibernation and i'm a bit confused!

i thought the point of a trickle charger was to keep the battery topped up when the cars stood over a period of time and things like the alarm drain the battery, just drive the car into the garage, connect up and switch on.

it says in the instructions that i must disconnect the battery before charging thus losing the radio settings and rendering the alarm/immobilizer useless.

have i got it wrong or what??

the charger is a streetwize accessories SWTBC for cars, boats, bikes etc.

That's probably more as a method for them to avoid any legal claims if any of the car systems (radio etc) stop working. Or as a way to keep battery discharge as low as possible - suggesting that it's trickle charger rate is not much greater than the batteries own natural self discharge rate.

In theory a trickle charger will be a lot less likely to cause damage than the alternator to other car systems, so should be no issue there.

As far as charge rate not keeping up with discharge, yes that might be an issue. You might need to periodically top up the battery with a proper charge still.

One thing to be aware of us that the alarm system may be triggered if car is locked and alarm active if charger cuts in with a higher voltage to make up for losses. You can get round that by locking the car using the key in the door, which will trip the central locking, but doesn't arm the alarm. NB: your insurance company may not pay out if it's stolen and they can prove you didn't set the alarm.

My advice would be to test it for a few days and see how it goes

I agree with G7', all that stuff will be damage damage limitation. The device you have, according to the info off the net is rated at 1.5amps & if the quiescent current of your car is in excess of that, it's tuned for smoke & needs a good going over with a test meter. These things are microprocessor controlled switch mode power supplies, they monitor the battery condition & adjust accordingly, the days of the transformer / metal rectifier / metal boxes have gone. Leakage current in my Land Rover is a way of life & as this type of chargers can be picked up so cheeply I have one built in; it cost under £7-00. If the battery voltage drops too much, a charger like this won't resurrect it as the current demand will easily exceed the charger capacity, you need a thump of a few amps to get it back into the target area.
Plug it in & get on with it. Mike.

I just attach my trickle charger with the battery in place and forget about it. I've never had a problem.

Acording to the instructions on the WEB the charger is fine connected to the vehicle!

charger