[Jack98]

Hey guys, time to upgrade the battery on my coily but I'm not sure where to look. I was looking at the optima blue top but I am not sure if I need to upgrade my alternator etc.. Any help would he great.

[want33s]

What accessories do you use/plan to use? Winch/fridge/lights etc.

[Jezza86]

your alternator will charge a bluetop if it outputs 14.2 V while your driving.
theres 2 types of blue top, beware
theres a light greay and a dark grey outer case. the dark grey is starting only. the light grey is deep cycle and starting.

[DMAC]

This question is quite common and people get mixed up with what function each component performs.

A battery is for storage of electric charge. Much like a bucket/tank for water.

An altenator produces charge for storage/use. Much like a hose filling the bucket.

Load (discharge) is what you have connected to the battery. What you're using the water for.

Load is the critical factor in determining your needs. If you camp alot and rely on battery power you need a larger amp/hr deepcycle battery. Where amp/hr is how much charge the battery holds. Big bucket big capacity. An altenator makes absoluty no difference as the engine isn't running. Capacity requirement is determined by load.
Eg.
Fridge 3 amp/hr run 24/7
Lights 1 amp/hr per 12watts. Run for 4 hrs
Stereo approx 5 amp/hr. (60 watt output) run 4 hours
Charging phones, navman etc 2 amp/hrs run 4 hours

From above for a 24hr period You need a t least(3*24)+(1*4)+(5*4)+(2*4) = 104 amp/hr battery to last 1 day without charging. Load has an effect on capacity and you need to refer to the tech spec for the battery. Eg. Capacity is determined at a set discharge rate. A higher discharge derates the battery capacity figure.

If you run a lot of accessories while driving. Ie. Big stereo, spotties, heater fan, etc. You need to add the load (amps) to see if it exceeds you altenator output. The water supplied by the hose to the bucket needs to be replenished by the water being let out of the bucket.

Eg.
High beam 120watts 10 amps,
Engine/parkers/dash lights 60 wats 5 amps
Stereo 60 watts 5 amps
Spotties 360 watts 30 amps
Heater/AC fan 60 watts 5 amps.

To run the above without flattening the battery you need a 55amp altenator.

People get confused when a winch is introduced. A winch is just a bigger starter motor. An altenator will never charge a battery as fast as a winch will discharge it. A winch needs between 200-500amps to work. So this is where the capabiliy of the battery to discharge s important. This in general is the CCA of the battery. Or think of it has how big a tap comes off you bucket.

The water will always go out of the bucket faster than you can fill it. The thing is you only winch for a short time therefore shouldn't empty your bucket. The altenator then determines how quickly your bucket is filled up again.

Hope this helps to answer your question.

[Jezza86]

que op coming online and saying 'i want to use it to start my car'.

[pete_79]

DMAC wrote:

This question is quite common and people get mixed up with what function each component performs.

Thanks mate, great explanation. I'm starting to look into a battery setup for our trailer and this helps a lot.
Cheers.

[Jack98]

Yeah that's awesome guys thanks. I want to just use it for a starter battery however I would like to run just some interior lights etc for camping. I have heard that you can get a product that has a volt meter that will disconnect the battery before it gets runs dead if your using small accessories off your starter battery. I've looked at dual battery setups but I only do little weekend trips so I wanna keep it simple. I spoke to a guy at battery world and obviously he just tried to sell me about 1500 bucks worth of shit so I thought this was a better place to get advice about a setup.

[Jezza86]

i don't know if a Optima d51 will fit the sierra. that's what we have been putting in the jimmy's of late. it has some deep cycle.

obviously though there is a cheaper option.
You can get rechargeable lamps with their own batteries that will be a shit tonne cheaper and mean you don't have to park facing down hill all the time...
more reliable, you can move them to where you need light, and you can afford 250 of them with what it would cost to buy a deep cycle battery in Australia.
US $0.94 a pop, free shipping.
http://www.aliexpress.com/item/MOQ-1PC-LED-Light-Underwater-Diving-Shallow-Flashlight-Torch-Lamp-Waterproof-Brightness/1321689537.html

[J--A--C--K]

D34 Optima's drop straight in to a Sierra , I can't comment on the factory terminals however as mine were already aftermarket.

[Jezza86]

skinny/jap= D34t1
au/normal/ euro/ US-D34 T2

assuming what jack says is correct and its not a battery with reversed teminals