Battery Ah rating
#1
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Battery Ah rating
Please excuse my electrical ignorance
I think the rating for my MY is 72Ah. I am looking at two batteries, Bosch S4, 74 Ah/680CCA and Bosch S5, 77 Ah, 780 CCA.
Is it ok to use a (slightly) higher Ah rating?
I think the rating for my MY is 72Ah. I am looking at two batteries, Bosch S4, 74 Ah/680CCA and Bosch S5, 77 Ah, 780 CCA.
Is it ok to use a (slightly) higher Ah rating?
#3
Rennlist Member
the cold cranking performance is the internal resistance of the battery which allows for the amount of current it can dump at one time, cold or hot.
this why i can run a odessy battery with 14 amp hours of capacity, and take adantage of its near 800CCA current dump potential. the difference, is that it cant dump 800amps for very long.
example. 14 amp hour battery can dump 28amps in a half hour, 56 amps for 15 min, 112amps for 7min, 224amps for 3.5 min, 450amps for 1.7min, and near 900amps for almost 45 seconds. (all in a perfect situation. actual results will be less)
this is what the amp/hr vs CCA means on the batteries.
oh, to answer the question, yes, no problem using a battery of greater or lessor amp/hour ratings.
Mk
#4
Chronic Tool Dropper
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Either will be fine. Both offer more than adequate cold cranking amps for starting your car. The amp-hour rating indicates, indirectly, how long the battery can maintain cranking demands. For most of us, the difference of 3 amp hours is moot.
#5
Rennlist Member
Rennlist Site Sponsor
As a practical matter, use the highest Amp/hr rating and cranking Amp rating that will fit in the battery box, and that you want to pay for.
I also greatly prefer to have a warranty that is good anywhere, so I often end up at Walmart...
I also greatly prefer to have a warranty that is good anywhere, so I often end up at Walmart...
#6
Pro
Higher battery ah can mean a slightly bigger battery, I have a BOSCH S4 80ah in my GTS and it's a very very tight fit.
I had to bend the lip in the battery well down on one corner
I had to bend the lip in the battery well down on one corner
Trending Topics
#8
Rennlist Member
Like Wally said, biggest that will fit in the holder. I am running an 88Ah in the 928, cos its whats specced, and fits. The Suby specs a 55Ah, but I can fit a 75Ah in , so thats what its got.
jp 83 Euro S AT 54k
jp 83 Euro S AT 54k
#9
Instructor
Join Date: Apr 2009
Location: London, U.K.
Posts: 148
Likes: 0
Received 0 Likes
on
0 Posts
#10
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Thread Starter
Yes that's the one.
Bosch has S6, S5, S4 and S3 battery models for our 928.
From their catalogue:
928 Type, model year, Ah, CCA, short code (4 choices)
4.7 09.82-11.84 95 850 S6 002 85 800 S5 010 74 680 S4 008 70 640 S3 008
S 08.83-07.86 70 760 S6 001 85 800 S5 010 74 680 S4 008 70 640 S3 008
5.0 GT 01.89-07.91 70 760 S6 001 77 780 S5 008 74 680 S4 008 70 640 S3 008
S4, S4/CS 08.86-07.91 70 760 S6 001 77 780 S5 008 74 680 S4 008 70 640 S3 008
5.4 GTS 08.91-11.95 70 760 S6 001 85 800 S5 010 74 680 S4 008 70 640 S3 008
http://aa.bosch.de/aa-batterien/de/p...g_2009_PKW.pdf
Bosch has S6, S5, S4 and S3 battery models for our 928.
From their catalogue:
928 Type, model year, Ah, CCA, short code (4 choices)
4.7 09.82-11.84 95 850 S6 002 85 800 S5 010 74 680 S4 008 70 640 S3 008
S 08.83-07.86 70 760 S6 001 85 800 S5 010 74 680 S4 008 70 640 S3 008
5.0 GT 01.89-07.91 70 760 S6 001 77 780 S5 008 74 680 S4 008 70 640 S3 008
S4, S4/CS 08.86-07.91 70 760 S6 001 77 780 S5 008 74 680 S4 008 70 640 S3 008
5.4 GTS 08.91-11.95 70 760 S6 001 85 800 S5 010 74 680 S4 008 70 640 S3 008
http://aa.bosch.de/aa-batterien/de/p...g_2009_PKW.pdf