Battery Drain Again (Sorry)

[Harry Harris]

I have finally got round to checking my Chimaera batt. drain, fuse by fuse; following advice to my previous post.
(Not so easy for a pensioner and in the cold !!)
The total drain is about 180mA (i.e enough to empty a fully charged 60Ah battery in a couple of weeks !!).
Almost all current (150mA) is thro fuse #6 which I believe is the feed to 'Alarm & Hazard Lights'.
Further small reduction with fuse #10 also out (Dash Lights + Clock).
Drain almost zero with Fuses 6, 10 & 9 (Ign feed + Fuseboard Relays) all out.
So, my problem appears to be associated with the Alarm unit.
Has anybody had similar? I assume my next step is to remove dash, then the alarm unit and send to a specialist ??
Would greatly appreciate any advice/observations though, still not gained much confidence in tacking these brutes.
Many thanks Harry

[Penelope Stopit]

Check if your alarm has battery backup, the battery for the backup will possibly draw current if good and definitely draw current if faulty

If you have a music system, check the wiring is correct, a mistake of mixing up the permanent and accessory supplies is often made when wiring radios and this scenario causes a permanent current draw more often than not

[Loubaruch]

Have you tried removing the large yellow relay that delays the internal lights. It is a known culprit for battery drain.

The old Meta alarm/immobiliser is also a possible, 180mA does seem rather high.

If your car is garaged and you do not need the alarm/immobiliser armed an inexpensive solution would be to fit an isolation switch to the battery this would stop all current drain and ensures that no electrical faults can occur with your car garaged.

[N7GTX]

That drain seems to be about right for a car fitted with the original alarm system i.e. 0.2a.

You could have a more modern alarm system fitted by a specialist - expensive.

You could fit a Battery Brain - a device that cuts off the battery discharge when it gets to 11.8v so the car should always start. There are basic ones to ones with remote controls.

You could hardwire a Ctek MX5 battery conditioner which will keep it in good health while not in use. By that I mean you fit the terminal lead to the battery which you leave fitted permanently and then a dedicated lead connects to the charger.

Or an Accumate conditioner which is a little cheaper.

I decided on the Ctek as I'd had one before.

[Argent]

Updating the alarm system, if it's a Meta, makes a difference, instead of a continuous field in the interior it's pulsed and draws far less from the battery.

HTH

A

[ChimpOnGas]

Argent said:

Updating the alarm system, if it's a Meta, makes a difference, instead of a continuous field in the interior it's pulsed and draws far less from the battery.

HTH

A

^^This is the proper solution, all be it a little costly^^

Or...if money is tight...bypass your current power hungry 1990's tech Meta security system and disconnect the microwave sensor, who pays a blind bit of attention to car alarms going off anyway? A simple hidden immobiliser switch is a very effective way to stop the car being driven away.

As already stated another option is to buy a Battery Brain device.

I've used, and been singing the praises of the Battery Brain for many years now, if you buy the version that comes with two IR remote fobs you can disconnect the battery after you've locked your car in the normal way, this not only solves the battery drain issue but adds a second line of defense against car theft.

https://www.batterybrain.co.uk/product/battery-bra...

Another benefit is that disconnecting the battery means you significantly reduce the risk of an electrical fire during long term storage, rodent damage to wiring and the short circuits that follow are a common enough issue for it to be good practice to disconnect the battery of any car left unattended in storage for long periods.

Up until recently you could buy this Battery Brain for £75, sadly it would seem the seller recently doubled the price to £150 which is annoying, saying that £150 is still a lot cheaper than a new Meta system and it will definitely solve your problem, well strictly speaking it will mask your underlying problem but the results will be to ensure you can always start your TVR.

I've been using my Battery Brain for five years now and have never suffered a flat battery, my mate 'Frenchie TVR' uses one too, while I use my TVR regularly he often leaves his Chimaera in his council lockup (no mains power) for months on end. Using the Battery Brain to disconnect his battery after the car is locked he knows its secure against theft and will always start first turn of the key, his council lockup is directly below a set of flats so reducing the risk of an electrical fire during these long term storage periods is reassuring too.