P.S. Charging without disconnecting the battery is fine; everybody does it.

 

P.P.S.

The battery's performance will be worse at lower temperatures. Nothing you can do about that either, except maybe heat it up

 

Yet another update.
I decided to have another look around, so I took the battery out.
I discovered that the heavy power leads that goes off to the altenator/starter have been cut off and replaced with another cable.
The replacement cable looks like it may be smaller in diameter. Also the connection to the main battery clamp does not look like it was well soldered in there.
I also have most of the service records for this car from new. It has a history of a lot of battery replacements.
So i plan to limp along till spring by charging the battery as required.
In the spring a complete tear down. Take out alternator, have it tested and rewire the big power and ground cables. This will not be too inconvenient as long as it is ok to charge the battery while it is still in the car and connected.
Txs everyone.

 

Be careful you don't overcharge. Use a battery charger you are positive shuts down when the battery is fully charged (floats) or you'll end up boiling it and doing more damage than good.

The distilled water question. It's better as it doesn't have the minerals in it that are in "tap" water. Those minerals will attach to the plates in the battery and will cause problems with the plates ability to produce electricity. The worse the water, the worse the problem. How much worse, how much life do you lose ??? don't know. Same with a cooling system. Distilled water is the better way to go for the same reason. The minerals will build up on all the surfaces and promote corrosion and hinder heat transfer.

As said earlier, temperature will affect battery readings. The colder it gets the less voltage and amperage will be available from the battery.
It's an old "trick" to bring the battery in at night to keep it warm (70 deg) for a cold Minnesota morning back in the old days. Before my car was built anyways.
Temperature is important enough that diesels will use electric battery blankets to heat the batteries so they get more amps out of them.


Where did you get a 48 ??? No one carries them here in the states anymore. I had to upgrade to a 24F with 750 CCA when my 48 died. I like having a little extra CCA in everything I drive. Also helps with the stereo.
The 24F has the same terminal arrangement, it's as wide but is a bit taller than the group size 47 that is the stock battery for an 850. The bit taller isn't a problem and no chance it's going to hit the hood.

 

A group 48 is easy to get up here (Canada). I now have an AC Delco group 48. It is speeced at 770 CCA.
Car will start, but when it goes down past -20C I have an 50W battery blanket that keeps it nice and cosy.
No problems starting.
I have also been running without my headlamps on during the day. I suspect i am only getting trickled charge with the current altenator.
When i come to a stop the voltage dips way down and then comes back up. Shouldn't do that in my opinion. I have the new altenator, just waiting for some spring weather to swap it out. Did not come with a pulley so Hopefully it will not be too bad to get it off the old one and onto the new one. It is good to know that the 24F will fit. I like good strong batteries in my car esphecially with a good sound system. ( note: until I do the swap out i have noe been using my heated seats nor playing the stereo so as to direct any current to the battery.
Thanks

 

Well . . . I went to search for a 48 and yup, they are back

Just one of those mysteries of life. I tried for a couple months to find one since mine was under warranty and even tried different suppliers as Autozone said I could return it defective and get a refund or exchange for a 47 and get the difference in $$ back too. I had even contacted their customer service and they said not available.

BUT . . . they are back on line at Autozone, Oreilly and Sears.
Glad I came across your post so I know it's still out there, thanks.