Urgent Info Needed

[fox1983]

ok i bought a battery from motor world only to find that its a 35ah not a 45ah the catalogue for exide states its a 35ah i need.
anyway my dads going to get a new one for me and i need to know what ah the alternator if capable to charge as i want to upgrade to a higher one due to the stereo etc.
any help asap would be greatful as my dad will get it monday for me
thanks

 

[SammoHung]

your standard alternator will acarge the battery no problem....but it will just take a little longer to fill it up.


the question is how much current are you drawing from all of your electricals. if the standard alternator can supply this while you are running the engine above idle than you will be fine.....battery is just a resivoure of charge for when the engine is off

Haynes reccons alternators are either 35, 40 or 50 AMP...may be there is a stamp on your alternator somwhere...?

Do you know what maximum power your extras are (audio etc)? this would help.

 

[fox1983]

god knows what power all my adio etc is as i got more to add on and i wouldnt know where to start to work it out
main thing i need to know is what battery would be my maximum and will it fit in
i was looking at getting something like a 55ah or 65ah to replace the 45ah

 

[SammoHung]

OK- the practical limmit to battery capacity is the physical size of the battery...that it will fit into the tray and still be possible to secure it from moving with the clamp or other type of reliable clamp....Also make sure that bonnet does not come neer the terminals when it closes.....if the bonnet is touching..it will eventually wear through the +VE insulator and short circuit the battery (danger explosion fire etc).

Also make sure that the terminal sizes on the battery dont move to the next size up as you move upwards through the battery capacities (Ah)otherwise you will have to crimp new terminal connectors on (pain in the bot)

Caution: no matter what size battery you fit...you will certainly go flat if your systems use more than your alternator/charging system can replace.

So if you can have a close look at your alternator and electrical gear (anything in Watts or Amps will be usefull) then thiswould be helpfull.

 

[fox1983]

ok the alternator is 40amps

all i can say is my power cable for my amps is running a 80 amp fuse
each amplifier has a 30amp fuse in i think
i may just go for a 45ah battery again and put a power cap on hopefully this will help

is it easy to replace the alternator for a higher amp one without having to do lanything else apart from bolting it in

 

[SammoHung]

provided that the electrical connectors to the are the same and the tentioning bolt doesn't snap..then its simple

 

[Antony]

why not just get one from halfords and all this info is on the side of the battery, with a 4 year guarentee....????

 

[Krian]

Because halfords want lots and lots of money for a car battery

 

[Speedle]

i wouldnt worry to much paul i used to run a hell of a alot more electrical stuff in my white k10 i just had a heavy duty halford battery and a new alternator never had power probs those halfords batts were brilliant!

 

[Arnold]

Yeah youve probably seen all the ICE in my car and thats running fine off a standard battery too. No point going overboard on batteries and alternators when its unnecessary

 

[fox1983]

im just getting a nissan 45ah battery and a power cap as i have been informed by a mate from sextons this will sort any power drain risk.i may get a new alternator too as mines looking a bit old

well my dad will hopefully be getting my battery today and ive just bought my power cap which will be here tomorrow so things will get sorted.

 

[Andrew]

Don't take this the wrong way, but power caps are a waste of time if they are used in the correct situation, and worse if used in the wrong one.

If your alternator is incapable of charging the battery, neither a larger battery or a power cap will make any difference at all. You either need to reduce the load, or increase the size of the alternator. There are no two ways about it.

I see nothing you have said to indicate that you have a problem with the capacity of the alternator though. Fuse ratings, watts and nameplates cannot be used as a guide to load, especially on car audio equipment. You need to measure the current drawn to know (and in reality the voltage, as it tends not to be constant).

Power caps, well, they aren't much use. The idea is to supply power when the amp draws enough current to cause voltage drop in the cabling. Therein lies the problem, you have voltage drop across the cables. Treat the disease, not the symptoms, as they say. Bigger cables.

But if your alternator can't keep up, having the power cap will make not help any.

 

[Gurpreet]

Which alternator did you get? OR more to the point where from?? Primera?? I need to get one in... cheers.

 

[fox1983]

i didnt change the alternator for now i got a 45ah battery from nissan and a power cap and its helped alot also put all new wires on the amps and getting some new cables for the charging system and earthing straps.