Do i need a bigger battery?

[mk1joe]

Hi,
Im looking at fitting some spotlights on the roof and maby one on the back, but im not sure weather the battery will be able to cope? At the moment i have the standard small battery fitted, and with the head lights on and the heater on aswell the battery warning light is starting to illuminate, although it never fails to start the engine would a bigger battery hold more charge and be more suitable for more lights?
The bulbs fitted to my new spots are 55w each, so will it be ok to draw more power from this battery or should i look at getting a bigger one straight away?
Also is there any better replacement for the "H3" bulb?
thanks,
Joe

[Tramp]

Your problem isn't the battery, its your alternator not providing enough current. Think of your battery as a bucket and electricity as water, it doesn't matter how big your bucket is, you need to have enough going in to match the amount going out!

If I was you I'd just fit them any way

[Jordi]

Sounds like the alternator may be on it's way out to me. The standard alternator should produce enough power to run all the light and auxillary equipment fitted such as a radio, heater, clock etc.

If your battery warning light is on running just the lights and heater there is a problem.

Jordi

[justaddmud]

Bigger Alternator x3, mine had the original 35 amp job on it, with lights and heater on it was a bit to much, maybe when it was new, but 25 years on both the alternator and heater motor are worn slightly, so it was probably only producing 25 amps, and the worn heater motor was probably pulling 25, add in 10 amps of headlights, 5 amps of stereo it soon adds up,

aim for as big as you can go on a V Belt, 60-70 amps should do the trick, be enough to power all sorts of lights and things

[Christoff]

Just adding my 10p. Also in favour of the alternator

While your engine is running, all the power comes from that, not your battery

The battery is sometimes referred to as a starter battery as this is basically what its for. Although poor batteries can also be the cause of other electrical faults and I also wouldn't attempt proper diagnosis without knowing that the battery is in good condition to start with

My advise would be to fit a higher output alternator and have the battery tested and replaced if in doubt.

Make sure you check all the leads and earths using the voltage drop method.

[mk1joe]

awesome! looks like im looking at a better alternator then:) does anyone know what the best replacement is? one off a vitara or something? and also how do you do the voltage drop method?

[Jordi]

I'm going with a 110amp pajero unit. Its a multi v belt pulley same as vit. Offered it up to the block and with some slight adjustment is an almost straight swap.

Haven't figured out the wiring yet though.

Jordi

[mk1joe]

cool, sounds like a plan i think il fit all the lights first and see how they work then will deffinately do the alternator afterwards when ive figured out the best way to. probably check out the interweb and see what other people have done.

out of curiosity, so if i was to draw too much power from the alternator while the engine was running, what would happen? would the engine cut out or would all the electrical stuff just go dim and naff?
thanks for the help guys:)

[Tramp]

They would just keep dimming until a certain point/threshold when your engine would die (not making enough electricry to supply your coil) if everything works on idle you should be ok as when your engine speed increases, so does your volts which reduces the current draw,

[mk1joe]

ah cool! thanks:)
so my next step it to wait for the lights to come of course, then i will rig em up and go from there. i will keep you posted.
thanks guys!