Battery drain

[ATG]

Battery was flat last Friday. Got the car going with a jump start, but was wondering why this had happened after ~only~ 10 days of being parked up without use.

I measured how much current was being drawn from the battery when the car is parked (engine not running, all lights off, ageing Meta alarm armed) and it came u as nearly 0.4 amps. Is that normal? Seems a bit high to me.

[macone]

ATG said:

Battery was flat last Friday. Got the car going with a jump start, but was wondering why this had happened after ~only~ 10 days of being parked up without use. I measured how much current was being drawn from the battery when the car is parked (engine not running, all lights off, ageing Meta alarm armed) and it came u as nearly 0.4 amps. Is that normal? Seems a bit high to me.

With a 65 Amp/Hr battery and supporting 0.4 Amps, all things being equal you'll get 10.4 days - however all things aren't equal. Your battery "capacity" is based on capacity "new" and at a 10 amp/hr discharge rate and you may have a larger or smaller battery anyway.

Point being, 0.4 amps is OK for about a week max on a good battery. Either you "discover" what is taking more than it should, or get a Optimate.

Trev McM

[ATG]

macone said:

Either you "discover" what is taking more than it should...

But is 0.4A more than it should be drawing?

[pbrettle]

One word - Alarm - its not a small drain on the battery from the ones that TVR fitted as standard. Either dont alarm it (not advisable) or keep it topped up somehow.

Maybe disconnect the battery next time and take it with you. That way the car is locked (being careful how you do this of course) and cannot be started. Battery doesnt go flat and everyone is a winner..... then again - just use it, even if its a short spin.

My battery starts to get VERY low after 7-9 days.

[edhorne]

My battery has drained over about a week with the car unlocked (in the garage obviously) and therefore the alarm not armed.

Does the battery energise the central locking solenoids to hold them in the unlocked position?

I have the battery on charge so I haven't been able to test my theory by leaving the car locked although I've never had battery problems before and left it for longer than this (but locked).

Any ideas anyone

Cheers

Ed

[macone]

edhorne said:

Does the battery energise the central locking solenoids to hold them in the unlocked position? Any ideas anyone Cheers Ed

Nope. The action of locking/unlocking merely "activates" the solenoid and in a cyclic fashion locks or unlocks at each activation.

There's a number of "electrical" circuits that are permanently live - the interior light and its timer take more than 10mAmps. I agree with PBrettle, the Alarm is high on the list whether alarmed or not. (I don't think the microwave detector is ever switched off). Next, on 93/95-ish cars is the relay control unit under the dash, that is never off either. I could on and on.

The answer simply is drive it every day or put a trickle charger (Optimate etc) on the car. Later cars are probably better at not having Transistor Controlled system, their ICs and digital systems are really either on or off. Us with older cars will just have to live with it - except when something is/has gone wrong !!

Keep smiling.

Trev McM

>> Edited by macone on Tuesday 11th November 13:33

[b9mgt]

I use a solar panel that plugs into the cigarette lighter. It cost about £20 and seems to work, but the longest I have left the car is about 10 days.
Does anyone know technically whether this is actually charging the battery - I've heard on some cars you have to attach the solar panel directly to the battery using the crocodile clips supplied?
Or is anyone else using the same device succesfully ?

[ATG]

b9mgt said:

I use a solar panel that plugs into the cigarette lighter. It cost about £20 and seems to work, but the longest I have left the car is about 10 days. Does anyone know technically whether this is actually charging the battery - I've heard on some cars you have to attach the solar panel directly to the battery using the crocodile clips supplied? Or is anyone else using the same device succesfully ?

You certainly can charge the battery via the cigarette lighter, coz otherwise none of the mains powered trickle chargers would work ... but can the solar powered device really be doing much good? I kind of doubt it. If my shed is anything to go by, your solar cells would need to be producing at least .4A at 12V to keep up with the ambient drain. That's actually quite a bit of power. Should be fairly easy to measure the solar cell's useful output. Try something like this. Engine off, headlights on to drain some power from the battery. Instead of plugging the solar cell in, connect it to the cigarette lighter sockets two contacts with a wire and a multimeter set to DC Amps. Any juice flowing into the car's electrics will be shown on the ammeter.

[raceboy]

Quick question before I update my christmas list.....
Optimate or Accumate ??????
The Optimate appears to be for sealed lead-acid gel and deep-cycle batteries used in back-up power supply applications.
Where as
The AccuMate is suitable for all 6 and 12V lead acid batteries from 4Ah to 75Ah, making it perfect for owners of older vehicles which are not used on a daily basis.

So from this I'd say I'd be needing to write AccuMate on my letter to Santa

[macone]

The "blurb" with my Optimate included not only , as you said, gel-batteries etc, but also "normal" lead acid. I use mine on my motorcycles primarily. I have a small "BMW" motorcycle trickle charger which is left on the TVR more so than Optimate - Optimate is better suited to small capacity batteries anyway !!! Whereas the BMW Trickle charger is what it says - so never overcharges, but unlikely to recover a flat/sulphated battery as an Optimate/Accumate can !!

Optimate came via Motorcyle Show at just over £30 a couple of years ago. Dunno how Leven justifiy their prices (and some TVR dealers !!).

I see Motorcycle Show is now on at the NEC - These Shows are always best place to pick-up bargains.

Keep chargin....!!

Trev McM

[GreenV8S]

ATG said:

You certainly can charge the battery via the cigarette lighter, coz otherwise none of the mains powered trickle chargers would

On mine the cigar lighter socket is ignition switched, so it isn't possible to trickle charge through it.

[macone]

GreenV8S said:

ATG said: You certainly can charge the battery via the cigarette lighter, coz otherwise none of the mains powered trickle chargers would On mine the cigar lighter socket is ignition switched, so it isn't possible to trickle charge through it.

I'm sure TVR are moving backwards when they introduce "newer" models !!!!

My '93 Chimaera has a two position ignition switch. Off, but only cigar sockets remain live everything else off and Ignition On, everything on (obviously).

Point being I don't have an "accessory" position between off and Ignition On - I have to have my Ignition On, fuel pump running, cooling fans running (if hot enough) just to sit and listen to the radio (look, if the engines's off, then I have to listen to something !!).

I've even taken the ignition switch apart to see if there is an accessory feed - NOPE !! What penny pinching by TVR from Vauxhall.

Had to wire radio into a live feed - not happy to see/hear ignition on/fuel pump primed just to listen to Donna Summer !!!

Sorry //rant over//.

Trev McM

[GreenV8S]

Oh well, the cigar lighter socket might switch off but at least the radio is permanently live so I can appreciate the cr*p reception with the engine off.

[macone]

GreenV8S said:

Oh well, the cigar lighter socket might switch off but at least the radio is permanently live so I can appreciate the cr*p reception with the engine off.

Yup, truely cr*p reception - hence Donna on MP3 capable radio/player - must investigate MOD and amplified aerial - more drain whilst at rest.....!!

[raceboy]

Well in answer to my own question, but I thought it maybe of use to others........

The sales people at Accumate said:

Many thanks for your email. The decision as to which charger is best suited to which task has to be governed by what it will be used for most of the time. If it is intended mainly for a modern motorcycle, the OptiMate is the right choice. If you need a maintenance charger mainly for use with a car, then AccuMate is the one to go for. Both chargers will work with both types of vehicle, but they are best-suited as above. Hope this explains.

So AccuMate for Cars, OptiMate for Bikes

[the dodger]

ATG said:

- snip-snip...I measured how much current was being drawn from the battery ..... and it came u as nearly 0.4 amps. Is that normal? Seems a bit high to me.

ATG - been there, done it, drained the battery. Mine was a case of "passenger door not shut properly". I was told (several sources) the immobiliser draws about 300mA. Clock and a few other micro electrics could soon have it up to 400mA easy. My cheap Draper trickle charger is rated at 300mA and does the trick!