Car battery sizing learnings

[Snagglefoot]

I thought I would start a thread on learnings and tidbits that people have regarding battery sizes. I'll go first.

I wanted to get a size 48 for my 2008 Suburban and checked out Walmart. They did not have one but did have a size 47 that was close. There was no one to hep there ( as usual) so I went over to NAPA is see what they had. The parts person looked up the vehicle and yes, it requires a 48, but she said a 47 would have fit. After I purchased the 48, I looked up a chart. Yes, the 47 would have fit but it would have been much smaller. Who needs that. So even if the drop down says it fits, it may be smaller but still fit in the hold down. OK if you're desperate I suppose but not ideal.

 

[JohnnyG]

My cars deal in what I think are the Euro/ISO sizes. A 47 is equivalent to an H7 and a 48 is an H8. Yes, both will fit in the battery compartment and the hold downs work exactly the same.
However, the two batteries are electrical capacity different. They'll work tho.
With the advent of computer programmed charging, I'm not 100% sure if they are interchangeable though,

So, I'll go second.

 

[D60]

I've decided "Group" sizes are chosen by the same people who name Jaguar models. It's a completely stupid system but it's been widely adopted and we're stuck with it.

 

[wavinwayne]

I learned that a new battery for my BMW weighs over 50 pounds and has to be finagled into place in the trunk in such a way as to avoid other unknown control modules that are in the way. This hurts my lower back, which is already no bueno.

 

[Donald]

Get the same group size unless your SOL stranded.

Get a diesel pickup with 2 batteries.

 

[skyactiv]

My 24' VW Jetta GLI has a H5/47 in it. My car does allow for a H6/48. Drop the battery in and use the other bolt hole. When I replace the battery I'm sticking to the OE size.

 

[johnmyster]

H6, H7, and H8 get incrementally longer...about 1.5" each. So if the hold-down is on the side or over the top, it'll still fit.

On the same token, if you have an H7 and have extra length in your tray, you can go to H8.

My truck is getting a pair of H8s when the present H6/H7 combo dies.

 

[Nukeman7]

Pretty much everything you need or want to know about battery sizes and configurations can be found here:

Battery Council International Group Sizes

You will still need to do the footwork to cross-reference the similarities and differences between each Group size.

 

[Opelman]

Get the same group size unless your SOL stranded.

Get a diesel pickup with 2 batteries.

Our buses use 2 8D batteries in parallel. About 130 lbs each.

 

[MyWifesBoyfriend]

Our Volvo has factory mountings for H5, H6 and H8 batteries. I don't know why they skipped H7, but nothing a piece of 2x4 can't fix...

I assume the different fitments are for different engines and factory equipment.

 

[FZ1]

I thought I would start a thread on learnings and tidbits that people have regarding battery sizes. I'll go first.

I wanted to get a size 48 for my 2008 Suburban and checked out Walmart. They did not have one but did have a size 47 that was close. There was no one to hep there ( as usual) so I went over to NAPA is see what they had. The parts person looked up the vehicle and yes, it requires a 48, but she said a 47 would have fit. After I purchased the 48, I looked up a chart. Yes, the 47 would have fit but it would have been much smaller. Who needs that. So even if the drop down says it fits, it may be smaller but still fit in the hold down. OK if you're desperate I suppose but not ideal.

Biggest battery that will fit is the Thang.

 

[marc1]

Two of my cars take a Group 24. Costco (Kirkland Signature) no longer carries Group 24 batteries (in Canada), however they have the Group 34 size. A Group 34 is 1" shorter than a Group 24 (l and w are the same) and will work fine for me when I have to replace the current Delco batteries as there will be no tray, mounting or cable issues.

 

[Donald]

Our buses use 2 8D batteries in parallel. About 130 lbs each.

I assume two people put the battery in place. More than I would try and lift.

 

[Danno]

I learned that a new battery for my BMW weighs over 50 pounds and has to be finagled into place in the trunk in such a way as to avoid other unknown control modules that are in the way. This hurts my lower back, which is already no bueno.

Durango, Grand Cherokee and BMW engineers must have had a competition on how to make the most difficult to access battery locations.
Under the front seats for the 2 Stellantis SUVs. And to access them you need to move the front seats all the way forward and up. Lotsa fun when the batteries are dead.
And then you have to remove and insert an AGM 40 lb battery at a 45 degree angle with zero leverage.
Fun times.
On another note, you cannot get a better location to place the batteries to lower the SUV's center of gravity.

 

[Snagglefoot]

For GMT 900 Chevy truck with #48 battery.

1. Remove negative clamp. Remove positive clamp
2. Remove fender corner reinforcement plate: 4- 15 mm bolts
3. Remove battery plate reinforcement bar: 2-15 mm bolts
4. Removed battery lock down clamp located down deep being hidden by battery positive cable.
5. If battery has built-in handles grab them and hoist battery at angle to clear cowl, using technique your chiropractor warned you about.
5b. If no handles screw around with a piece of rope or try clutching battery, or use a terminal wrecking battery lifting gizmo.
6. Lift battery up and over fender edge, another back wrecker.

I will only buy batteries with built-in handles for this vehicle after that AC Delco episode.

 

[oil pan 4]

I say bigger = better.
Vehicle batteries are one of those things where more is more.

 

[D60]

Durango, Grand Cherokee and BMW engineers must have had a competition on how to make the most difficult to access battery locations.
Under the front seats for the 2 Stellantis SUVs. And to access them you need to move the front seats all the way forward and up. Lotsa fun when the batteries are dead.
And then you have to remove and insert an AGM 40 lb battery at a 45 degree angle with zero leverage.
Fun times.
On another note, you cannot get a better location to place the batteries to lower the SUV's center of gravity.

Transit vans the same. Engineers have never been taught the concept of circular reasoning:

1) to remove a dead battery, move the power seat forward
2) uh........

Eric O had a great vid on a GC fighting the battery under the seat. He somehow found a short and a blown master fuse from careless installation. Actually a great watch for people to see how those who service vehicles have no choice but to accommodate poor decisions by those who design vehicles:


Let's take a quick look at your battery, lady:

 

[RaymondP]

Size matters. But surprised no one is talking about specs. as in CCA and ah. In latest generation of vehicles (last 15+ model years) life has become a lot more complicated due to demands placed by onboard electrical systems, including stop start. Imperative you at least match the minimum spec of the OEM battery. You also MUST register the battery to tell the charging system (battery management system - BMS) a new battery has been installed. This requires a compatible OBD bi-directional scanner. Newer car charging systems vary the charging rate of the battery based on the battery's age. Older batteries receive a higher charging rate as they age. If not registered the new battery will have a shortened life as it will be overcharged at the old battery rate.

Secondly, if the ah of the new battery is different to the previous battery, the BMS will need to be reprogrammed for the new ah. My OEM BMW Varta H8 is rated at 900 CCA and 92ah. New H8 batteries have similar or more CCA (a good thing) but are also specified at 95ah. I think a +3ah variance is NOT an issue as most OBD readers don't seem to differentiate between 90ah and 95ah settings, so I won't need to reprogram, just register the BMS for the new battery once installed.

By no means an expert, just reading up a lot and talking with others so please feel free to chime in. My current AGM H8 is still good after ten years. Hoping it gets through this cold spell and I haven't jinxed it.

 

[nthach]

The three newest Toyotas in the family fleet all use DIN batteries. The JIS designations are LN1/LN2/LN3 I think. Which interchange to BCI 47/48 for LN1/LN1 I think. They’ll all stick with the stock size, either Costco Clarios or Deka(Napa/AAA). One will get a regular flooded battery.

 

[TacoFergie]

I always put the biggest battery in that will fit, always AGM and use X2 or Odyssey when possible. Interstate used to be a solid brand as were a few others. But over time many brands have changed sources with questionable reliability. X2 and Odyssey are made by NorthStar which used to be the top tier choice, but they no longer make consumer grade batteries under their own name. They are expensive, but they last a long time!