MGB Register Forum

The location of the MGB battery doesn't inspire regular maintenance. I became fed up of removing the seat wrestling with recalcitrant dzus fasteners etc. so nearly 10 years ago I fitted an AGM (absorbent glass matting) battery that had previously been on my Land Rover. As the MG has an untraceable electrical leak it's connected to a battery minder when not in use.
This battery (a single 12 volt) has just expired so I ordered a new one from a firm in Norfolk. The battery is an Optima Red Top 8002-250 which fits the battery tray perfectly.
They are more expensive than conventional ones but they are totally maintenance free and the one being replaced is about 12 years old so I think good value.
Optima do 6 volt batteries as well.
. Vic Butler

Hi Vic
I may have a leak somewhere - still at diagnostic stage - ''battery minder'' ? Could you expand a bit please with size, where to get, price etc.
Thanks

Evening Tony.
My battery minder is an Accumate Battery Conditioner and Charger available from the MGOC. It comes with a lead with crocodile clips and a lead with ring connectors for permanent attachment to the battery. The rings will need reaming to fit the battery leads. The optional 2.5 metre extension lead to the battery is worth having.
The battery lead comes under the battery cover and the connector is behind the driver's seat. It's just a matter of connecting to the charger and the lead can pass through the window. Easy to disconnect before driving off. It's suitable for all battery types, lead acid, calcium, AGM. I have the latter. The minder can be left connected to the battery indefinitely as it tops up only when needed. The whole package including delivery was just under £60. There is an optional wall mounting bracket but I didn't bother with it.
AGM batteries are totally maintenance free and although expensive they last for a very long time. The previous one had been on the MG for over 9 years and prior to that it was on my Land Rover for over 2 years
I think my leak is the ignition switch which I replaced some time ago which was when the problem started but I can't be bothered to replace it and then find out it wasn't the cause.
Hope this helps
. Vic
.

Battery No 063 also fits the battery tray but you do have to cut the mounting lugs off the bottom of the short side. This probably invalidates the warranty, but the one I bought last year was under £40.00 so I didn't consider this to be a problem! It started the car without difficulty after standing from mid November (NEC time) until the end of March.
Problem with classic cars is they don't get driven often enough to keep the battery fully charged. This is an even greater problem if the car has a dynamo, as they need something like 1500rpm to provide a charge. Alternators are much better as they charge at tickover. A battery conditioner is better than a battery charger as it 'exercises' the battery through a series of charge/discharge cycles (although they never allow it to completely discharge!), but they do take longer to recharge a badly discharged battery than a battery charger.

I have an 063 in mine but the lug hadn't been cut off by the PO and it wasn't sitting properly on the battery tray, so I corrected that. I have an isolation switch fitted just behind the passenger seat, and always switch it off if cars unused for any length of time, to prevent any leaks,but have to leave it on when connected to optimate under the bonnet.. works well..

Like Dave I have a battery isolation switch fitted to the bulkhead behind the passenger seat, in my case isolating twin 6 volt heavy duty batteries. I use a CTEK battery charger which has a connector fitted permanently to the battery posts and a small connector which sits at the edge of the rear seat/shelf just above the isolation switch. This makes connecting the charger very quick and easy, and I can disconnect the batteries from the rest of the vehicle whilst leaving the charger connected.

IanF.

Hi All
I been using a CTECK conditioner /charger for many years . I purchased the optional connector lead that allows the charger to be plugged into the cigarette lighter socket as this is permanently live on the MGB. Makes connection /disconnection really easy when wanting to use the car. As the current involved is very small, the difference between the battery terminal voltage and voltage measured at lighter socket is a few 10's of millivolts (Ohms law) so dosen't affect the charge to the battery.

That sounds like a good move, Vic. Hope I can remember when my fairly recently fitted 12 volt battery dies. As for the slight electrical leakage, this is something I came across some years ago and overcame (but no cured) by fitting a master switch (as fitted on competition cars) on the carpeted front face of the battery box, low down behind the driver's seat, on the left close to the tunnel where it is accessible as you sit on the seat. It is an effective deterrent for thieves too as I can, and do, remove the "key".