Explain car batteries to me please.
 

So my DD has an H7 battery that is no longer holding a charge. I can not find much on this class of battery. But as I understand the old class numbers they most are the battery case size and terminal location. Any reason I can not replace an H7 with a different class so long as the CCA's, terminal location and reserve are equivalent? and of course the battery is secured? No special technology or anything I am missing in an H7? Seems ridiculous to spend $200.00 plus if I can get an equivalent for $80.00 or so.

No reason I can think of.

No reason in my book.

However, looks like Interstate has it....

Does the H7 completely fill the battery box?
Our CR-V had a smallish battery, relative to the battery box size, so I upped the group size no problem.
I'd check out the size and see how big a battery you can fit in there.

Yes, H7 fills the tray. An H7 is huge and heavy compared to the 27 battery in my Nissan. I only need this to start, don't need deep cycle or anything. Current H7 is 700 CCA? I wouldn't mind a little more CCA's but many smaller batteries have higher CCA's.

It used to be common to equip new cars with batteries that were smaller than the battery box was designed for. The new truck I bought did not have this "feature" though, so I don't know how common that practice is now.
The new car I bought in February came with a full sized battery. It was a Chevy Volt. :D

As long as the connectors are in the right location and your cables can reach them, you can put just about anything that'll fit in there I'd think.
I just about doubled the CCA's when I went to the Group 24f in the CR-V. Guess Honda was worried more about weight/gas mileage than putting in something that could handle the electrical load of a new car's electronics.

Thanks guys, you all have validated my thoughts. Much appreciated.

You can go smaller too, if the CCA's and all the other parameters of fit are met too.

Isn't it the alternator that handles the electrical load?
I think the battery is just a storage medium and, to a small extent, a voltage leveler for surge demand.

To the OP:

A car battery is a mechanism whereby electrons which are stored through a complicated chemical process can be released and directed to various electrical mechanisms (via conductors i.e., wires) to perform work.*


*No offense, please. I spend time on some fora wherein my answer (which is an attempt at humor) to your question is totally appropriate. Its unbeleviable to me that there are so many people out there who haven't a clue about just about everything.

True, but the way Honda has the charging system programed to only charge under certain conditions, all in the name of gas mileage, it isn't conducive to short trip usage.

what is your DD?

the 930 battery is a rather large battery. I replaced mine with a smaller but same CCA batt. just make sure you can bolt it down.

I notice you are in NJ where it gets cold.

From living in El Paso a few years back I found out that there are hot climate batteries and cold climate batteries and that heat if far more destructive than cold.

So just add that to your kit bag when considering purchase. My understanding is that the different types are only sold in those environments so it should not present a problem for you.

As long as it meets minimum power requirements and fits you should be good to go.

What Matthew said is true, at least as far as heat being hard on batteries.

I'm not personally aware of batteries being tailor-made for hot or cold environments.

I'll try and answer you all with out specifically quoting each of you.

Yes my thought was to go smaller in dimensions but larger in CCA's. I am aware a battery is just a storage device. My issue was the H7 classification seems to be rather rare along with an H8. I couldn't locate much information on it. The vehicle is a 2007 Jeep Commander Limited. It has some devices but nothing seemed out of the normal that would require anything special. Yes I am in NJ and was looking to bump up the CCA's as well.

My question was simply was there anything special about an H7 battery that I was unaware of that for some reason would prevent me from using a different class.

This...and I believe many (most?) newer cars are adopting this "feature". So, when battery shopping, I would put more weight on the amp-hour and/or "reserve capacity" ratings, assuming the CA/CCA ratings are at/above the minimum requirement. Also, the cars with these "variable" charging system seem to do better with the glass mat (AGM) type of battery. Or, it may just be a factor with the heavy-load nature of newer cars with 184 different power-sucking options running at once.

I just went through this last month, and couldn't believe what an ordeal it is these days to simply change a battery. My DD (5-series) has a similar "intelligent" battery system, and it takes a massive H9 AGM. Not only was sourcing one that size a chore (and not cheap), but the car has to be coded/programed and the new battery "registered" whenever replaced. So, in addition to the battery I had to purchase a specific OBDII scan tool with the battery coding capability. All in all, it was still cheaper than taking it to the stealer, who wanted $500+ for the job. Crazy...

Interstate battery climate zone link. Hot climate battery: "Longest life in hot to moderate climates due to high electrolyte-to-lead ratio"

Climate Map | Get reliable extreme weather batteries from Interstate Batteries

Talking about those... We had our first dead battery (no warning whatsoever) in a modern car with a push button start. That was fun ! No way you can just jump it, you need to let it get boosted a few minutes before you can even light anything up on the dash, then hold that start button while the computer goes through system checks and after 10 seconds maybe it'll try cranking.. Ah, for the good old days of a key, 2nd gear and a bump start ;-)

Yeah same deal, put in a smaller battery of higher CCA and all is well.. Old one read 8V despite 1.5 hours drive home on the alternator... Then I had to reprogram windows and sunroof, all on youtube. Cars are getting complicated ;-)

Good point. I used to see PANO ads for a 9V battery device you could plug into the 12V female power outlet to keep radio memory when changing batteries. Would such a device still work with today's cars that have more electronics? If so, are they still sold?