Replacing the Battery

[tkew]

I chk with AB mech they say is ok to change the bat no resetting needed...

 

[leakwoon]

in GT1 got 1 faultlog

batt. something someting

i got it clear last weekend

 

[tamade7]

changed mine to din 100. ngam ngam fit onto the tray

 

[Mouse]

changed mine to din 100. ngam ngam fit onto the tray

walau eh, i think among E46 owner u uses the biggest most powerful battery, beware when u ON your aircond coz might blow your wig away
anyway, how much is DIN 100 and what brand?

 

[tamade7]

bro tikus i changed mine to koba korean made mf rm500 with a yr warranty. e46 tray fits 66 85 88 and 100. on the tray it has a plastic stopper for smaller battery. since i am using 100 i just remove the stopper.

 

[geodesy]

Hey Geo here...

Wanna get out this afternoon and couldn't crank the car up. So call up whoever can bring a battery to me and here's what I paid -- $250 for Century MF black in colour. DIN66 for a E34. It was a DIN55 :O Please can sumone tell me why it's so cheap and if 66 is suitable for E34? I dowan to be caught at the roadside during the festive seasons...

Cheers,
Geo.

 

[LCP]

It is okay to fit a slightly bigger battery, by about one size step or so. But remember that bigger battery equals more weight and hence slightly higher fuel consumption.

 

[bal3056]

It is okay to fit a slightly bigger battery, by about one size step or so. But remember that bigger battery equals more weight and hence slightly higher fuel consumption.

Difference in weight of DIN66 & 88 is so negligible that it will not hurt or increase your fuel consumption.

 

[bal3056]

Hey Geo here...

Wanna get out this afternoon and couldn't crank the car up. So call up whoever can bring a battery to me and here's what I paid -- $250 for Century MF black in colour. DIN66 for a E34. It was a DIN55 :O Please can sumone tell me why it's so cheap and if 66 is suitable for E34? I dowan to be caught at the roadside during the festive seasons...

Cheers,
Geo.

DIN66 is absolutely fine with E34s esp M20b20/b25. Having been using for years on all the BMWs I've had and absolutely 'no dramas'.

 

[philwoo]

Bosch s3 - (maintenance free)
din55/din55r = rm 260
din66 = rm 275

 

[initialM]

I just changed mine wt Century MF DIN88 cost RM400

 

[food_lover]

correct me if im wrong, higher din its meant higher Amp right..? Higher Amp meant less crank when you want to start the engine.. My experience when i tried higher amp.. i notice that my engine tunning tend to be lower than before.. As the chain reaction to this, my acond start creating problem since the tunning is too low, A/C will not come in.. only fan blow.. well, after re-tune the problem still did not solve, so i changed to lower din back.. well, that my experience..

 

[astroboy]

The amps means the load the battery can supply. Usages is base on electrical draw. Say the headlight is drawing 55w, using the Ohm's Law, V=IR, V is voltage, I is "arus" measured by amps and R is resistance or load measured by watts.

So 12v=I(55w), therefore I=12/55 = 0.2181 amps for a single bulb, so keep adding la for your other electrical usage until u hit the maximum load of the battery rating. Additional draw after that will show weaknesses to supplies, thus your headlight brightness will reduce.

For the E90 OEM battery, DIN 100L which is rated at least 90AH (Ampere/Hour) is very high, double of a Kancil N40 battery.

What you need to worry is the alternator rating. Imagine using a 90AH battery in a car with 40AH alternator.. it takes forever the charge the battery and will kill the alternator fast because it never cuts out, constant working not stop. On the other hand, using a 40AH battery in a car with 90AH alternator. That will heat up the battery fast and will boil the battery fluid, thus resulting in vaporisation of battery fluid, lost of fluid and the acid vapor can cause rust to the surrounding metals if poorly ventilated.

That's why ICE enthusiasts upgrade battery to support the additional AV equipments, then will soon realise alternator kaput. After which they must upgrade to a bigger alternator or else, they will have to keep replacing alternators..

Back to the starter issue. If the starter is 300w, then it will just draw 300w despite having a 3,000w battery. But if the battery can't cope with 300w, then only you will experience slowness in the crank, and that too will load and heat up the battery, fluid loss as well as a result.

Oh yes, correct me if I'm wrong..

 

[t2ribena]

brader...u use the wrong ohm's law la...

Yes V=IR but R is load/resistance and it is in ohmic value and not watt...

watts is Power and it is express by the equation, P=IV, so based on your example,

55W = I x 12V, rearranging you will get,

I= 55/12 = 4.58A

next your assumption on the battery current ratings and the alternator is also not correct ler...when u use a 40Ah battery with a car with 90Ah alternator it is ok as the charging current depends on the battery, in fact with higher current availability the battery will charge up faster...the only thing is that when u use smaller battery for say 40Ah, when ur car requires 80Ah let say for ICE show off without engine runnning meaning alternator not running, ur battery will be fully drain in 30min...

for the starter, 300W translate to current rating of about 25A...so battery that do not have enuf charge may be too week to supply this as the inrush current for an induction load could be as high as 6 times the nominal currrent...in this case when u start the starter motor, it could require up to about 150A of current!

the 12V system in cars has reach its limit actually versus the cables thinkness since the electrical and electronics grows trumendously in cars...in EU they have been talking about 48V as it offers better solution to the current needs but till now no one (car manufacturer) is starting it yet...

 

[astroboy]

hehee... just testing if there's a better guru around.. finally found one.. :wink:

Yep... my ampere figure for the 55w bulb is kind of low I noticed, so I just taruh and hope an angle will come to my assistance..

Your 4.58A sounds about right otherwise the 10A fuse would sounds crazy for protection of 0.21A..

 

[t2ribena]

i am no guru la...i go find in wikipedia one...lol

 

[bimmerdude]

so, what is the recommended battery rating for the e90 320i?

 

[astroboy]

so, what is the recommended battery rating for the e90 320i?

OEM is 90AH. DIN88 is not enuf. That's all I know..

 

[Spaceman]

i had checked my batt which is 70ah. why lower than E90 320i?

 

[astroboy]

See the label.. 90AH.. but I remember mine is a white color battery, not black.