Need battery info!

[RIBS]

The cold has driven the last nail in my batteries coffin.

what’s the group size/cca. Type info I need?
I don’t care about stock, concours etc…I just want it to fit and perform.
71 302 c4 convertible. aftermarket wiring harness 3 G alternator, probably 90+ amp rating….
Don’t wanna break the bank!
thanks!

current battery fits, might be little small in tray.

 

[mjseakan]

I put a group 27 battery into my '73 302. I believe CCA would be whatever you feel you need. I get the highest I can afford at the time. I don't know if having a vert comes into play for battery choice. I have a coupe.
Mike

 

[RD-72]

Changing the subject slightly
Cost of batteries, just like everything else, has gone up in price over that last few years.
I just replaced a battery for my Acura MDX on the weekend
old one was cdn $120 in 2019 at Costco...new one last weekend was CDN $170 ($50 increase over 3 years)
beauty with Costco was that it has a full replacement warranty for 4 years, so i got my $120 back (so net, the new battery cost me only $50j

 

[Spike Morelli]

I believe the correct battery physical size, just off the top of my head, is a group 24F. I have AC and would look for the highest CCA rating. Also, don't by-pass looking at your battery cables, replace them if they aren't up to snuff. ( The positive cable is short and easy to do. )

 

[RIBS]

Ok thanks all. Getting a 24F 750cca $119. Seems reasonable for 3 year warranty.

 

[Bobby]

I get Interstate batteries for all my vehicles. The are more reliable than the AutoZone Duralast and usually anything the big stores have. Get the highest CCA you can. I buy mine at Firestone Shops.

 

[mrgmhale]

For First Generation Mustangs I like to use a 27F, with as many CCAs as I can find. It may be overkill, but that is fine with me. I always get the highest quality battery from the vendor I am buying from. Many batteries are made by only a few actual manufacturers, so performance differences may not amount to much. I am impressed with the various ways things are tested by Project Farms (YouTube channel), and the other day happened to come across this gem re: car batteries. It is worth watching, but be prepared to be surprised with his findings!

 

[Hemikiller]

My last 24F Everstart MAXX lasted 12 years, then I gave it to a friend for his project car. Still cranking strong. I have one in my 11 Outback, it's seven years old.

Bought a new 24F earlier this year, they were about $100, now they're up to $120-ish. Still the best deal around.

Don't waste your money on an Optima, their warranty is crap and the product is crap. They were worth the money when they offered a 10 year guarantee, now it's three years and good luck.

Everstart is offering their own line of AGM batteries. They haven't made it to all areas yet, but they're out there. For $170, it's a decent deal if that's what you're looking for.

https://www.walmart.com/ip/EverStart-Platinum-AGM-Battery-Group-Size-24F-12-Volt-710-CCA/286630898?

 

[Bobby]

For First Generation Mustangs I like to use a 27F, with as many CCAs as I can find. It may be overkill, but that is fine with me. I always get the highest quality battery from the vendor I am buying from. Many batteries are made by only a few actual manufacturers, so performance differences may not amount to much. I am impressed with the various ways things are tested by Project Farms (YouTube channel), and the other day happened to come across this gem re: car batteries. It is worth watching, but be prepared to be surprised with his findings!

Correct. Johnson Controls manufacturers 90% of the batteries in the US…..along with the automotive glass and seating. The different vendors give their spacs to JC and then JC complies.

 

[351c1971]

The Costco/Interstate AGM battery at $179.00 is a great deal. AGM means no acid corrosion in the battery box and very low self discharge during storage.

You will usually have to call individual stores to check stock. This cannot be done online because it is on the InterState site not the Costco site. You can also call Costco corporate to see what Costco warehouse they shipped these batteries to.


EXCLUSIVE FOR COSTCO
Group Size: 24F AGM

$179.99*​

Item Number	1421400
Group Size	24F AGM
CCA	710
CA	885
Voltage	12
RC	120
Ah	70
Length	10 15/16
Width	6 13/16
Height	9
Weight	45.3
Termination Code	TOP
Wet/Dry	D

 

[351c1971]

You should also use a smart battery charger that supports AGM technology.

 

[Hemikiller]

Johnson Controls sold/spun off it's battery division, which is now called Clarios. East Penn is another good manufacturer. Their own line is Deka, and they also make batteries for many parts stores, OEMs etc.

Who makes what battery for whom changes all the time, and can vary by the battery line, maybe even by the Group #.

Just as an aside, if one is replacing batteries every couple years, there's something wrong with your electrical or wiring system. It could be as simple as dirty connections, a corroded cable, or maybe, as a last resort, the alternator. Don't be too quick to replace parts willy-nilly. A few hours spent cleaning, repairing and ensuring proper connections will pay dividends for years.

 

[Stocktrader]

My 7 Johnson Controls batteries lasted 3 years and 4 months then turned off like a light switch. Didn't matter how I treated them. My Mercedes batteries also made by Johnson Controls in Germany with a silver oxide additive go at least 8 years and I have 1 in my garage over 10 years but no home for it. Point is they can make a great battery when they want to but for common folk it's going to be 3 years and 4 months no matter what. You are leasing the battery.

 

[donkost]

Funny, the Everstart MAXX H6 is the same battery that's in my Saab 9-3. I've been using that brand in our daily driver vehicles for quite a number of years. Yes Deka is also good, and located not too far away from me. My next door neighbor works there. My '71 Mach 1 429 calls for the group 27F and I might go with that as it's ready for replacement. I was considering the classic looking AGM battery (Jegs etc.), but it looks like they no longer have the words Autolite and Sta-Ful in red. Considered a battery topper as well, but it's a nice clean driver and not really a show car.

 

[kevken1959]

On this subject, I have been using the Autolite topper on several of my batteries. Sometimes I have to enlarge the holes in the topper to make it fit. The case needs to be black. The top of the battery has to be flat with the caps flush with the top. The options are limited. Does anyone have a "perfect go to" battery for use with the Autolite battery topper?

I was so happy to see someone finally makes a Motorcraft topper, but it looks too small for use with a 24F, and it is made in Australia which makes me wonder if the measurements are the same as what we use in the USA. Has anyone used this topper?

Thanks!

https://www.ebay.com/itm/124969805997

 

[Phisto]

Forgive me if this question is already posted on the forum somewhere but I couldn’t find. What’s the correct battery size for a ‘71 w351C? I’m reading on this thread 24F or 27F, but that seems to be for a 302. Interstate’s website tells me a 24F or 27F won’t fit mine. I want to keep it stock size. TIA.

 

[Sheriff41]

24F is standard and used on 250, 302, and 351C, unless heavy duty battery option was on the car from the factory. I don't know if the 429 cars used the 24F. The 27F is the heavy duty battery. 24 or 27 is the case size and F is the post (+, -) configuration. The battery tray in the car should tell you which size your car came with as there are two size battery trays.

 

[mrgmhale]

24F is standard and used on 250, 302, and 351C, unless heavy duty battery option was on the car from the factory. I don't know if the 429 cars used the 24F. The 27F is the heavy duty battery. 24 or 27 is the case size and F is the post (+, -) configuration. The battery tray in the car should tell you which size your car came with as there are two size battery trays.

On my 69 Mach 1 I had to replace the battery (back in 1974 or so). I decided to get a 27F instead of the oem 24F, just for the added amperage. It would not fit in the battery tray. Rather than buy and wait for a 27F size tray I used a large pair of pliers to bend one of the tray ends flat so the 27F would sit in the tray "kind of" properly. I was not worried about the one end not having an upward bent wall as the battery hold down was plenty to keep it in place. I ended up doing that to another Mustang belonging to a friend years later for the same reasons.

 

[roboconklin]

On my 69 Mach 1 I had to replace the battery (back in 1974 or so). I decided to get a 27F instead of the oem 24F, just for the added amperage. It would not fit in the battery tray. Rather than buy and wait for a 27F size tray I used a large pair of pliers to bend one of the tray ends flat so the 27F would sit in the tray "kind of" properly. I was not worried about the one end not having an upward bent wall as the battery hold down was plenty to keep it in place. I ended up doing that to another Mustang belonging to a friend years later for the same reasons.

34r is higher amperage and not too big

 

[KSpence]

An obvious note, but whatever you do, be sure the posts are correct. Keep that positive terminal toward the firewall/solenoid ...
You probably are already all over that ... but the number of Mustangs that I've seen with those crossed up makes me cringe ... having the positive terminal so close to the radiator support ... yikes!!