Just bought one of these...
quote:
# For most petrol and diesel engines with 6V/12V lead acid batteries.
# Suitable for 12V lead acid batteries with a capacity between 7Ah - 180Ah
# Trickle charge 3A RMS, fast charge 12A RMS.
# Reverse polarity protection.
# Short circuit protection.
# Thermal overload.
# Mains on LED indicator.
# Analogue meter shows the battery charging status.
# Automatically switches to float charge when battery is fully charged (12V fast charge only).
# Metal case.
quote:
# Suitable for use with 12 volt lead acid car batteries between 20-225 Ah.
# 12 amps RMS normal charge rate and 2 amps RMS trickle charge rate.
# Built-in auto reset breaker for short circuit, reverse polarity and thermal protection.
# Full charge automatic switching to maintenance mode.
# LED showing charging status and reverse polarity warning.
# Conforms to CE safety regulations.
# Standard battery charge time from flat 225Ah - 20 hours.
# Suitable for over 1800cc engine size.
# Petrol / diesel.
They are both wrong if you want to leave them on trickle charge as they will both shaft your battery.
I bought a proper charger (can't think of the name and my other garage is away from here!) which cuts off when the battery is charged and only
starts charging when the battery has dropped to 95%.
Optimate springs to mine although mine is not one of those!
I'll do a bit of digging on ebay to see if I can find one!
Here you go
ebay
Its a Ctek and keeps my red top 25 Gel battery in good condition
I have a Draper "Intelligent" battery charger that works well, it just charges when it needs it and cuts off when charged, you can leave it
connected indefinitely and it'll keep the battery in good health.
It wasn't silly money (obviously or I wouldn't have one) 
You can't use 'em for electrolysis though, you need a "normal" one like you have..
[Edited on 3/3/08 by UncleFista]
Not really after something I can just leave on... I just need to be able to charge the battery as I have yet to get the car started and testing
elctrics etc has run it down a bit so it hasn't got enough umph to turn her over now....
Other issue is I need it today! hence the trip to Argos...
I should use the one you've got on fast charge and just switch it off after 2 hours or so.
I bought a 'Battery reconditioner' for £35. It has all the trickle charge stuff plus it magically reconditions the battery if it thinks it
needs it. If the battery hasn't recovered after three attempts to recon, the machine switches off and sends you to buy a new battery. I had a
battery that wouldn't hold charge, probably due to being on my car for over a year and never used. The magic machine charged it, trickled it for
an hour or so and then went into 'recover mode'. The battery is now back on the car and manages to work whenever it needs to even if
it's been a month without use.
It says on the box that it is suitable for all 12v batteries.
Here it is...My magic charger and mender of batteries
[Edited on 3/3/08 by owelly]
where'd you find one for 35? Best I found is 45...
Try ebay acu guard bike charger £30 delivered will keep any battery tip top car or bike.
I bought my charger from Scarborough Race Developements for £35. He also had a few of the smaller 'Plug Top' chargers for £10 IIRC. I bough
two of them as well!
http://www.scarbro-racing.co.uk/
[Edited on 8/3/08 by owelly]