Quote:
Originally Posted by DirtyDan ...
Add up the total number of watts you you expect to need to power all of your electrical stuff as if you had it all turned on at once. Then take this number and divide it by 13. This will give you a rough idea of the amps you need. So, then, get an alternator that puts out more amps than this figure by about ten percent in case you want to add stuff... |
Well summarized DD.
Quote:
Originally Posted by Samurai ...So, can a 35A alternator charge an 80A battery? Probably not, so I'll need a bigger alternator if I switch to bigger battery. In that case I'll pass for now. |
Samu, if by "an 80A battery" you mean 80A-h battery, that seems to be plenty! The choice really depends on how long you plan to be running your electrical devices for when the car is not running - and if your alternator has lesser capacity than the load drawn, how much the difference is and for how long your car will run like this.
You might know this but i will repeat it for the benefit of all :
80A-h (amp-hours) is the capacity of the battery. It means it
can deliver 80amps for a period of 1hour before it is completely discharged. It could also provide 1amp for 80hrs or 40amps for 2hours, - any combination where Amps x hours is = 80 or less.
Lets do a rough add up for all the lighting in your car (See similar post here :
http://www.team-bhp.com/forum/techni...tml#post330850) :
Headlights = 90watt x 2
Fog lights = 60watts x 2
Tail lights = 30watts x 2
Total = 360watts
P(watts) = V(volts) x I(amps)
360w = 11v x ???A (<< i have chosen 11volts for a worst case scenario)
360w / 11v = ???A
360w / 11v = 32.7A
360w / 12v = 30A
360w / 13v = 27.7A
So 32.7A is probably your worst case draw from the lighting with this setup.
Your alternator charges @ 35A, so it seems you are just in the clear.
For eg. if your draw was 5A more than the alternator provided, it would take you 80/5 = 16hrs (with an 80A-h batt) to run out of juice completely. (However, remember that you never want to kill it completely since you will need some charge to crank-start the engine - which is the time the most current is drawn from the battery. Very exhausting.)
I wouldn't reccomend cutting it fine (though you can re-do the math with the exact numbers) - but
this is exactly where the ammeter will help tremendously! If your in the +ve youre fine. If youre in the negative, depending on how far in the -ve you can figure out how long you can safely continue!
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Originally Posted by Jaggu ...push start, well if its a case where you lost the juice in battery, switch on ignition>press heater if its manual>engage 2nd>depress clutch>push>gather momentum>release clutch and switch the starter through ignition and disengage clutch. Last part helps if your battery has lost a cell and would help the starter fire up the engine faster.... |
Sounds really painful for the starter assembly!! Why would you want to do that at all? (even if the battery has lost a cell). The only time i can think of doing that is if you just cant push the car fast enough yourself...
EDIT: Or by "ignition" do you mean "on" and not "crank". -- maybe i have misunderstood since i would usually turn the car to "on" before push starting.
cya
R