• Hi Guest!
    If you appreciate British Car Forum and our 25 years of supporting British car enthusiasts with technical and anicdotal information, collected from our thousands of great members, please support us with a low-cost subscription. You can become a supporting member for less than the dues of most car clubs.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

The size of battery for 62 BN7

Share this page

AH67

AH67

Senior Member
Offline
Hi All,
what size of battery, spec or brand should i get for my 62 BN7? Every store I go to gives me a different answer..
 
Assuming a single 12V, Group 24 is usually cross-referenced for Healeys and fit fine. I buy 'generic' 12V lead-acid batteries from a local parts house; the last one lasted nearly 7 years (it still cranked fine but showed marginal on a load tester, and I was getting ready to take a long trip). Costco has good batteries, but don't know if they still carry Group 24. 500 CCA or more should be sufficient for a well-tuned engine. Since the batteries are in the rear, it's important that the cables are copper and in good shape. We used 0 (gauge) cables on our BN2.

I believe all lead-acid batteries are made by only 2 or 3 companies (Johnson Controls being one of them). The length of warranty and CCA rating are rough general indicators of the overall build quality--price may or may not be--but this isn't definitive. A good, 'conditioning' trickle charger--Battery Tender is the one I use--will help prolong the life of a battery, esp. if your car isn't driven frequently.
 
Last edited:
AH67 said:
Hi All,
what size of battery, spec or brand should i get for my 62 BN7? Every store I go to gives me a different answer..
Click to expand...

My recent (last week) experience: my 65 month Interstate lasted 3+ years. AutoZone I bought the car with in 2000 lasted 9 years.

Bought a Delco this time. They are made in the US and supposed to last longer because the Mexican batteries use less pure lead.

Star Auto Electric no longer carries Interstate because they had too many early failures. He's the one who says Delcos are the only US-made lead-acid batteries. I think MotorCraft are, too, as the 5-year warranty card also showed that logo.

Bought a group 58. I think they are a little shorter than the group 24s.

Never considered a gel battery as they'e over $200 and my charger won't handle them.
 
I'll second the thumbs down on Interstate batteries. My Mustang came with an Interstate and it barely lasted 3 years (just past warranty). Worst of all, it didn't just fail, it leaked, which is the worst thing a battery can do. Major cleanup job.
 
I put a Sears DieHard Grp 26 in June 2009. It is warranted to 2015. The most important thing is to keep it charged on an automatic battery tender given the usual underuse of the battery/car. My last DieHard failed before the warranty period and I got a great reduction on the replacement. I had not regularly kept the battery charged up during the winter. I'm trying to do a better job now. It has functioned great for the past 4 years. Mine is mounted under the rear battery access cover on the passenger side. I use a generic tie down system.
 
I just recently purchased an Energizer Max 27F for my BT7, found it at Sams Club. It fills the battery tray better and also places the terminals towards the fender for a cleaner look:


image.jpg
 
Shane said:
I just recently purchased an Energizer Max 27F for my BT7, found it at Sams Club. It fills the battery tray better and also places the terminals towards the fender for a cleaner look:


View attachment 28403
Click to expand...
The 27 and 27F are different because of terminal locations and of them works great for Neg ground cars.
 
I have another concern about battery size. On my bj7 I have switch to an alternator. I have always believed that the size of a battery was based on the electrical load (especially the starters need) and the capacity of the charging system to recharge it. The original generator was about 25amps output and my new alternator is about 65amps output. Should I use the same size battery that I was using when I ran it with the generator? I believe I had a group 24 w/525 CCA. Dave.
 
vette said:
I have another concern about battery size. On my bj7 I have switch to an alternator. I have always believed that the size of a battery was based on the electrical load (especially the starters need) and the capacity of the charging system to recharge it. The original generator was about 25amps output and my new alternator is about 65amps output. Should I use the same size battery that I was using when I ran it with the generator? I believe I had a group 24 w/525 CCA. Dave.
Click to expand...

I installed a Smiths voltmeter and my alternator charges at around 13.5 volts. Star Auto Electric told me that was correct. They said if you're charging at 14+ volts you might boil away the electrolyte. IMHO if the regulator is working properly the size of the battery shouldn't matter to the alternator.
 
Steve, I believe I will have to differ with you on your last post. If you have an exceptionally large battery connected to a system that has a very small charging capacity, the charging system will never satisfy the battery and it will charge continuously trying to get the battery up to a charged state that it can hold the system designed voltage. The charging "dynamo" in this case our generators will try to maintain the system designed voltage (approx 12v+) no matter how many things are turned on. If a battery is in the system and it is not charged to the system designed voltage or to the voltage that the battery is designed to hold, then that battery appears to the "system" as a load and the generator will try to supply it. Once a battery has reached its system designed voltage, then the voltage regulator would lower the output requirement of the generator. But if the battery never can come up to its voltage, then the regulator will keep the generator charging. And this could be to the generators demise. As an example of a generators ability to self destruct, many years ago when I bought my Healey, one of the things I rebuilt quickly was the generator. To my surprise when I took it apart was that the solder in the commutator leads had become so hot that is melted and the solder was slung out by centrifical force in that it was splayed all around the inner casing of the generator. Surprising, the generator was still working. But after I repaired and installed it, checking the setting on the regulator, it appeared that the regulator never allowed the generator to not charge. I believe the overcharging was distroying the generator. So I suppose that an alternator will just charge the exiting battery faster to its designed voltage. And I suppose that 525 cca is sufficient for the electrical load that I will be putting into the Healey. But if you consider extra electrcal load than original, such as, fog lights, a very good stereo, auxiliay power for ipad and cell phones, etc. Now that I have a 65amp alternator, might I want a larger battery? Dave.
 
Dave, where I was coming from is I never heard of anyone having to change the battery out to a different size because of adding an alternator. Quite a few folks have installed alternators without using larger batteries.

Your original post didn't mention new electrical loads.

Respectfully, the generator issues discussed above sound like a special case and not relevant to the alternator. Apples to oranges. :smile:
 
vette said:
Steve, I believe I will have to differ with you on your last post. If you have an exceptionally large battery connected to a system that has a very small charging capacity, ... Dave.
Click to expand...
The difference in size between the various starting batteries that will fit in a Healey is insignificant in this regard. It would make a difference only if one was filling the trunk with batteries.

I have two "modern" cars, built within the last 8 years. Both have alternators that will supply far more loads than the Healey will ever have. Both of them have batteries that are surprisingly small, even though the engines are at least as big as the Austin, and with higher compression ratios. Starting battery size is determined by the ability to start the engine, listed as cca.

Also, the generator or alternator regulator doesn't govern the generator or alternator power output. It only governs the output voltage up to the point that the voltage can no longer be maintained because of a high load. The output is governed by the difference in voltage between the load and the generator or alternator, and the resistance between them.
 
Thanks to All. Points well taken. Dave.
 
Back
Top