Does everyone here disconnect the main battery before attaching an external 240v charger?
What exactly is the reason that it always asks for the battery to be disconnected before charging?
Surely all of the components connected to the battery get a 14v feed when the alternator is running?

Thanks for your thoughts

I've never disconnected a battery from the car to charge it.

With my CTEK I've even got a connector permanently connected to the terminals so that all I need to do is plug it in - the connector came with the charger.

I guess if you had a faulty charger, then disconnecting would protect the rest of the car, but that's all I can think of.


[EDIT] - I just took a look at the CTEK instructions and it seems to be a differentiator for their intelligent chargers that you can use whilst the battery is connected. So maybe disconnect if you have a basic charger ?

On the basis of recent experience of going from a pre-CANBUS motorcycle to one that has it, where I needed a new charger that was CANBUS compatible, my guess is that if a non-CANBUS charger would put your electronics at risk the battery should be disconnected before charging. This might result in the loss of existing settings, so a CANBUS compatible charger would be the best choice. Perhaps someone who knows more about this in the context of the RR could confirm.

I used my pre-CANBUS charger (2010 vintage) on the rear socket of my 2004 322 without problems, but would not try it on my current car. Only Range Rovers since 1988

I think the issue charging motorcycles with a canbus system is that the canbus isolates the accessory socket when you switch the bike off so a standard charger can't connect to the battery through it. A canbus compatible charger sends some sort of signal to the canbus system to tell it to keep the socket live.

I also bought a ctek charger and a permanent hard-wired connector for the FF. With all the expensive electronics on board I didn't feel inclined to risk anything that didn't explicitly state it was safe to use with the battery connected (plus I really needed a float charger as it often stands for some time). 2011 5.0 S/C

Used Ctek for years. Never disconnected the battery at any time.

All working well - (doh shouldn't of said that ) 405 AB exec seats Baltic and Cirrus
93 RR Classic efi

Remember it's easier to get forgiveness than permission!

Gone in order:
4.4 TDV8 SE - gone to a good home
93 Classic hard dash Plymouth Blue
03 L322 Oslo Blue
2000 Disco TD5 ES Epsom Green
98 P38 Rioja Red
89 Classic Cairngorm Brown

I’m the same as Alistair, in having the CTEK connector wired to my battery and the plug strapped to the lower front bumper.
Makes is so easy to just plug in and leave it. Got - 2017 SDV8 Autobiography in Loire Blue
Had- 2008 TDV8 Vogue SE in Java black
Had - 2007 S/C in Stornoway Grey

assuming you have the same 10mm live terminal connector as we do here , it takes just seconds to undo it so why risk it ? ive known folk spike the ECU by leaving it connected ( not on a 322 ) , risk is yours or buy a c-tek as that's seems to eliminate the risk

I also have a ctek socket connector permanently attached to my battery. The socket connector also has a LED light to indicate battery charge level so I know when to plug in the ctek. ______________________________
Vogue tdv8 08MY poverty pack - wow

I have been looking to buy something a bit more gentle than my rather bulky Ring charger. I also like the idea of having a hard wired charging lead. My requirements are mainly to keep the batteries topped up on my 5.0 RR and my 3.2 BMW.

I have been looking at the MXS 5.0 which seems to fit my bill but wondered what you guys are using? Will this be up to the job? The 10 amp model is a LOT dearer.

Another question: From the pictures, the holes on the connectors of the hard wired kit seem quite small. Where are you hard wiring to?

Cheers, Mark Current Cars:
MY11 5.0 SC Stornoway - sold
MY06 TD6 Zambezi - sold
1997 BMW E36 M3 Evolution Convertible Estoril

Mine is an mxs 5.0 and it seems to cope well. I try not to let the battery run down too low so it hasn't had to work that hard. Certainly fine for keeping it topped up.

For hard wiring I bought the CTEK indicator lead with M8 eyelets and connected it straight to the battery terminal clamps. The lead isn't very long so I pass it out the top of the bonnet by the wipers. When it's not being used it tucks neatly under the trailing edge of the bonnet and I can just pull it out to check the indicator lights or connect the charger without having to open the bonnet. 2011 5.0 S/C

I have the same ctek mxs 5.0 with connector left attached. The connector has the LED charge indicator. This set up works well. ______________________________
Vogue tdv8 08MY poverty pack - wow

I got the CTEK 3.7A which also works fine either charging a pretty flat 020 battery or topping up (obviously takes longer to charge though than the larger charger).

For my hardwired connection, I got the CTEK 2.5m extension cable (about £12). Have the connector just poking through the radiator grill (releasable cable tie holding it in place). Then cable routed (in some plastic spiral wrap) behind the headlight and down the side of the engine bay. Cut cable to length (2.5m is far too long) then earth via an eyelet onto the earth point on the suspension turret, and live via an inline 5A fuse holder (eBay) to a small eyelet, which I have connected to the battery bulkhead fitting by drilling/tapping for a small screw into the side of that big nut on that fitting.

https://www.defa.com/product/chargerkit-1204/
This is the commercial kit I have charging my full fat as I write this. Comes with a decent plug to hook up whenever needed.

Thanks for the replies guys - appreciate you all taking the time.

kanikune - that Defa kit looks pretty good but for availability here, I have ordered a Ctek MXS 5.0 which will be delivered tomorrow. I also ordered the extension cable but of course, forgot to order an extra hard wire kit for the BMW

Thanks again guys.

Cheers, Mark Current Cars:
MY11 5.0 SC Stornoway - sold
MY06 TD6 Zambezi - sold
1997 BMW E36 M3 Evolution Convertible Estoril

Might be a bit late to the party with this but if you have a towbar fitted don’t overlook the towbar electrical socket option, available in the Shop (above menu bar at top of page, next to Wiki button).

Just plug in the adapter to the towbar socket and connect the charger, no hassle at all.

https://www.disco3.co.uk/shop/tow-electric...c-p45.html 2006MY 4.2 SC
BMW R1250 GSA Rallye TE
Triumph Tiger 1050 (sold)
1979 Pontiac Trans Am (sold)