Battery advice required

TaDa · Nov 28, 2011

My Disco let me down this morning - the battery had no power.
truth be known - I let it down by leaving the same battery in it since new (2000 - is this a record?).

So I need to get a new battery...

I've seen the alphaline one at Performance Batteries | Your Online Store for Car Batteries, 4x4 Batteries, Light Van Batteries & more
I don't _need_ a more powerful battery but I'm tempted - anything better out there?

Lastly, is it a fair test of the alternator to start the motor and disconnect the battery. I assume that if the engine remains running and can run main beam then the alternator must be ok?

Cheers

TaDa · Nov 28, 2011

Well I looked around but could not find any readily available obvious replacement bargains batteries on the web.
I chose not to buy the dealership replacement for £164
In the end I took a punt on a Varta Blue Direct 830 cca battery which cost £114 from a local garage!
Its not as long (from battery terminal to battery terminal sides) but is a little wider (from front to back) so it does not fit well in the battery holder - it was dark and wet when I fitted so maybe I'll check that later. But it clamped down secure enough.

Thus far its been ok having started the engine twice

Sean · Nov 28, 2011

TaDa said:
Lastly, is it a fair test of the alternator to start the motor and disconnect the battery. I assume that if the engine remains running and can run main beam then the alternator must be ok?

Cheers

I hope you didn't do this ?

ratty · Nov 28, 2011

TaDa said:
My Disco let me down this morning - the battery had no power.
truth be known - I let it down by leaving the same battery in it since new (2000 - is this a record?).

So I need to get a new battery...

I've seen the alphaline one at Performance Batteries | Your Online Store for Car Batteries, 4x4 Batteries, Light Van Batteries & more
I don't _need_ a more powerful battery but I'm tempted - anything better out there?

Lastly, is it a fair test of the alternator to start the motor and disconnect the battery. I assume that if the engine remains running and can run main beam then the alternator must be ok?

Cheers

What's wrong with just connecting a voltmeter onto the battery and making sure that it's charging between 13.8 and 14.5 volts with the engine running?

Freediscoranger · Nov 28, 2011

dont disconnect the battery with the engine running.... could seriously fry some electronics. the battery is used in a parrelel circuit with the alternator to smooth out the voltage given from the alternator to make the AC into DC (along with lots of diodes and other electrickery)

in short terms just dont do it

stchris356 · Nov 28, 2011

1, What ever you do, DO NOT disconnect the battery whilst the engine is running!
2, Like many thing in life, you get what you pay for but moreso with batteries,
get a cheap one off eblag and it will let you down, I'd go for a Halfords Calcium or a Bosch and if the budget won't stretch that far (mine won't) get a Halfords standard, I've had a few on my cars over the years and they've never let me down yet!

ratty · Nov 28, 2011

stchris356 said:
1, What ever you do, DO NOT disconnect the battery whilst the engine is running!
2, Like many thing in life, you get what you pay for but moreso with batteries,
get a cheap one off eblag and it will let you down, I'd go for a Halfords Calcium or a Bosch and if the budget won't stretch that far (mine won't) get a Halfords standard, I've had a few on my cars over the years and they've never let me down yet!

I've fitted a few Halfords calcium batteries to customers cars. I don't get as much discount on them as I do on normal batteries but as I pass my discount on to the members anyway they can't complain.

CharlesY · Nov 28, 2011

The BATTERY is essential in the alternator system.

It is the battery that tells the alternator how hard it needs to work.

Basically, the lower the battery voltage, the harder the alternator will work to try to increase system voltage to about 13.8 volts nominal.

With the battery disconnected, there is ZERO volts in the system, and the alternator voltage regulator goes berserk (and probably on fire inside) trying to reach the required level, which it can never do as there's no "reference voltage" because the battery is out of the circuit.

I reckon your alternator might fry in ten seconds if the engine speed was up a bit, and perhaps a minute or so at just over tickover speed.

Basically, it's very unwise to let the engine run the alternator if the battery is disconnected.

CharlesY

Snifflebag · Nov 29, 2011

TaDa said:
I've seen the alphaline one at Performance Batteries | Your Online Store for Car Batteries, 4x4 Batteries, Light Van Batteries & more
I don't _need_ a more powerful battery but I'm tempted - anything better out there?

I replaced my battery with one of these the other week. The company does the business in terms of delivery and the battery appears a good replacement.

TaDa · Dec 2, 2011

You'll all be glad to know I did not do this.
Though, I confess, more because it was raining than anything else

In the end I used a multimeter to check the voltage across the battery was over 14V when the engine/alternator was running - which it was.
The new battery is still going well

Cheers all!

Battery advice required

TaDa

Active Member

TaDa

Active Member

Sean

Banned

ratty

I'm not special I'm limited edition

Freediscoranger

Active Member

stchris356

New Member

ratty

I'm not special I'm limited edition

CharlesY

Well-Known Member

Snifflebag

Active Member

TaDa

Active Member

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