cmonkey713

Using a new 90%+ charged 600 CCA battery how long would the battery retain enough reserve power to start the car drawing with after market accessories drawing 3 to 4 amps per hour at 70 degrees. I have reviewed some data but it makes no sense to me. Do I need to provide additional battery info? Would an AGM or Lead/Acid be the best choice. Thanks

LMB-Z

4 days, 6 hrs 37 min. 19 sec. What are you wanting to know? How long can the car sit before the battery goes dead? Just put it on a trickle charger once a week for 24 hrs, or just keep it on when not driving the car.

cmonkey713

The question is, if the car is sitting with a 90%+ battery charge, and power accessories (amps, strobes and such) drawing down the battery at a rate of 4 amps per hour approximately how long will the battery last and still start the car? I would like to have about six hours and still have enough power to start the car. I don't know how to even begin to estimate the time before battery charge is too low to start the car.
Thanks

LMB-Z

It should last at least a week and still start the car. At least, mine does. If my car sits for more than a week or so, it won't start. So 6 hours should be good to go, unless you are listening to the radio with a large amp and the car in acc mode. Just sitting with nothing turned on, should last at least a week, maybe two.

cmonkey713

That's the issue, everything will not be turned off for about six hours. There will be amps and such running for demo purposes resulting a constant draw of about 4 amps per hour for the six hours.

LMB-Z

I doubt seriously it will last 6 hours with an amp running, much less anything else. Might need to keep a charger on it.

NY09C6

Not long at all. Maybe the battery is 60ah, if your drawing 4a per hour you car likely won't start after 8-10 hours.

cclive

I would be willing to bet that the car would not start after 6 - 8 hours at that kind of load. A deep cycle battery would be best for that kind of draw as a regular car battery doesn't like being discharged that much. You could just keep a second battery to jump the car after the display is over.

rkj427

best to have it connected to a charger, especially with the constant draw/load you will have it under..........

AORoads

You seem to be talking about being at a show and having everything working w/o the engine running or out at a camp site doing about the same. I don't know the answer for your car with that load and the batt. you're talking about.

But, from past experience on here over the many years of C6s, some guys pull their relatively new, charged up batts. in their cars outside to wash and wax and then can't start the car. That's after maybe an hour or two of drain from a stock stereo.

4SUMERZ

If your battery reaches less than 90% charge, then it will not likely start the car. Discharging the battery to that level is not ideal, because it will shorten the life of the battery significantly, especially if it occurs frequently. This will eventually cause a short in one or more of the cells.
It's best to keep it on a tender if you are using your car battery to run lights etc at a car show.
Better yet, have a spare deep cycle battery for that purpose.

bassman50

There is another figure the battery label should have and it's the "reserve capacity". This is the number of minutes a fully charged battery at 80 degrees F is discharged at 25 amps before the battery's terminal voltage falls below 10.5 volts.

This factor is normally used to provide an idea how long your car might run if the charging circuit fails. Given that the C6 is finicky about battery voltage anyway, I'd doubt that even a good reserve capacity number like 150 minutes would allow you to run accessories for as much as the 2 1/2 hours with any significant current draw and then start your C6. I'd look for the largest capacity battery you can find for your purposes.

Steve

cmonkey713

After talking to an Interstate Battery engineer in Dallas today the answer the the question is " The car will not have enough reserve power to start if a 4 APH draw (Which is quite a bit) is maintained for six hours". The Interstate engineer did say based on a 600 Amp CCA rated battery and after doing some calculations he indicated a total of three hours in 15 or 30 minute acc. power on intervals the car should still start. That being said any deep discharge situation is extremely hard on the battery severely limiting its operational life. The solution is to get a deep cycle high reserve battery and connect the accessories power source to it and not the car battery. Unfortunately No deep cycle battery will fit in the C-6 battery location, about two inches too long. Interesting infromation here might be helpful to someone in the future using the Search function.