has anyone noticed a big difference in a second battery?

[mustanggt5330 10+ year member]

dropin below 12 and dont know if its worth it.. i wanted someone who had exsperience in doin this with good results....

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[azimuth 5,000+ posts]

a little bit. i'm going for a ho alty as soon as funds free up.

 

[tapout 5,000+ posts]

Go with a second batt first. If that doesnt fix it, go with a HO alt.

 

[mustanggt5330 10+ year member]

ok would an HO alt solve all my problems? with only a battery under the hood.

 

[mustanggt5330 10+ year member]

bump......

 

[GoochJuice]

we need some info on your setup to even begin to answer this question.

for example...what good is an HO alt if you have a 1kw amp and are dropping to 12.1v? its probably a good idea, to make sure we know what your setup is, so that we can verify there isnt an install issue going on first, before you start splurging money on what could be unnecessary upgrades.

 

[Duke 10+ year member]

Big 3 done?

 

[djjdnap 10+ year member]

second batt usually just gives u more car off time of playing....just adds strain to alt with it on.

 

[GoochJuice]

second batt usually just gives u more car off time of playing....just adds strain to alt with it on.

not really. yes they work when the car is off.

however, they are also a support for the alternator. voltage is dependent on how much draw is being pulled from the battery and is relative to the amount of reserve (no, not the RC, im just using this word interchangeably with "storage") that the battery has. bigger batteries will of course have more room to store. take a 500cca battery (cca's are not the only spec, but im using this for simplicity) and put a draw of 150A on it. then take a 1000cca battery and put the same draw. your voltage drop will be considerably less on the 1000cca battery because in the bigger picture, you are taking a smaller percentage of power away. think about it this way. if i have a 3 gallon bucket and remove 1 gallon, im left with 2 gallons. now take a 5 gallon and remove that same 1 gallon, and you're now sitting at 4 gallons. the alt will provide as much current as it can, and the rest has to come from the battery.

now adding a second battery is even better than running 1 single bigger battery. while adding to all the specs (IE 2 batteries act just like 1 bigger battery), you are also lowering ESR because you are wired in parallel. lower ESR means faster recharge and discharge.

 

[djjdnap 10+ year member]

NOPE

if i got 3 1 gallon buckets and I'm emptying them out then refilling them, its gonna be easier and faster to refill those 3 buckets that it is to refill 5 buckets.

But true if i'm not emptying the buckets that fast it would be easier to conserve more because i have more to fall back on

also u gotta think about how fast u can refill those buckets..aka ur alt..

lol, perspectively speaking

 

[GoochJuice]

NOPE
if i got 3 1 gallon buckets and I'm emptying them out then refilling them, its gonna be easier and faster to refill those 3 buckets that it is to refill 5 buckets.

But true if i'm not emptying the buckets that fast it would be easier to conserve more because i have more to fall back on

you didnt read what i said, or you misunderstood it. i said remove 1 gallon from a 3 gallon bucket. and 1 gallon from a 5 gallon bucket.

you are missing a gallon from each, but one will contain more reserve (ie, voltage).

 

[GoochJuice]

NOPE
if i got 3 1 gallon buckets and I'm emptying them out then refilling them, its gonna be easier and faster to refill those 3 buckets that it is to refill 5 buckets.

But true if i'm not emptying the buckets that fast it would be easier to conserve more because i have more to fall back on

also u gotta think about how fast u can refill those buckets..aka ur alt..

lol, perspectively speaking

yes, but we are not talking about that.

1 battery will discharge to a specified level. now putting two batteries in parallel will divide the draw and make it easier on the batteries because you didnt drain them down to dangerous levels, while still giving the alt the same amount of work to do (instead of charging 1 batt up 100%, it has to charge 2 batts up 50% each)

 

[mlstrass 5,000+ posts]

I agree on doing the 2nd batt, then adding an HO alt if needed.

I ran 2 1500D's off an HO alt and still got some dimming, so I added a 2nd batt and dimming stopped. Already had BIG3 and good batt up front...

 

[helotaxi 5,000+ posts]

Which is more important with an air-compressor when using an impact wrench, the air pump or the air tank?

 

[motox_727 10+ year member]

Which is more important with an air-compressor when using an impact wrench, the air pump or the air tank?

Haha yeah you made a good point, obviously the tank, in this case aka the battery.