Battery charging procedure

[Jerome P.]

Should the car's battery be disconnected from the electrical system while it is being charged?

If it is not disconnected can damage occur?

I have a new Delco battery installed and I drive the car, at most 60 miles a month and want to keep the battery at a full charge.

[Richard G.]

Re: Battery charging procedure

I just install a battery tender and leave the system connected.
It will work fine.
My batteries are lasting for years now.
No damage will occur if the battery is connected or disconnected. Your choice.
Check the reports for a good battery tender, some of the ultra cheap will over change the battery.

[Terry M.]

Re: Battery charging procedure

Should the car's battery be disconnected from the electrical system while it is being charged?

If it is not disconnected can damage occur?

I have a new Delco battery installed and I drive the car, at most 60 miles a month and want to keep the battery at a full charge.

Define: "while it is being charged"

Does the battery need charging (5 or 10 amps or more) between uses?

Are you looking for a maintenance charger (<2 amps)?

Different situations and very different answers.

[Jerome P.]

Define: "while it is being charged"??

I want the battery to maintain the best possible charge between each occasional start up. The car is often parked for a couple of days at a time and at other times parked for 2 or 3 weeks without starting it.

As I mentioned the battery is new. I am looking to do what necessary to get the longest usable battery life.

[Russ S.]

Re: Battery charging procedure

What Richard says -plus add a disconnect switch and use it.

[Richard G.]

Re: Battery charging procedure

Russ;
I didn't mean to imply a disconnect switch isn't a good idea. I just don't believe if your only consideration is only battery life that it makes a difference.
However, for safety's sake I do recommend the switch. And install it on the ground side!
My insurance company, NCM, applies an additional discount if you have a battery disconnect on your car.

My 06 Corvette, that sits a lot during the winter, doesn't have a cut off switch but I do use a battery maintainer.
I prefer to keep the computer alive. Much different animal than the 1972's.

[Russ S.]

Re: Battery charging procedure

Richard, You didn't imply that.

Russ;
I didn't mean to imply a disconnect switch isn't a good idea. I just don't believe if your only consideration is only battery life that it makes a difference.
However, for safety's sake I do recommend the switch. And install it on the ground side!
My insurance company, NCM, applies an additional discount if you have a battery disconnect on your car.

My 06 Corvette, that sits a lot during the winter, doesn't have a cut off switch but I do use a battery maintainer.
I prefer to keep the computer alive. Much different animal than the 1972's.

[Duke W.]

Re: Battery charging procedure

I just replaced a 17 year old basic Johnson Controls fifty-dollar 26R battery that I actually killed stone dead twice over that period on a car that doesn't have a battery disconnect switch. It's parked for typically one to three weeks between drives. A day before I plan to use it I connect a conventional 2/6 amp charger on the 6 amp setting, and when the ammeter goes down to 2 I switch to the two amp setting and it goes to zero, which means it's fully charged. So it's on a car for an hour or two.

A typical "no maintenance" battery looses about one percent charge per day at room temperature due to internal leakage plus whatever load is on it due to clock, memory system refresh, alternator leakage... so after three weeks it's about 30 percent discharged. If you consistently demand cranking voltage at this level of charge it will sooner or later never come back to full charge due to a sort of "chemical memory", so if you want long battery life, always make sure the battery is fully charged before cranking. This isn't an issue on a daily driver, but IS on an occasional use car.


I don't think a constant trickle charger is a good idea. It's best to let the battery cycle a bit, but those so-called "float chargers" that detect voltage and turn the charger on periodically when voltage drops slightly due to discharge may be okay.

On a vintage Corvette the parked load is the clock and a slight leak path through the alternator, so a battery shut-off switch will eliminate those loads, but you will have to set the clock every time you drive assuming you want the time to be accurate.


Typical parked load on a vintage car is about 20-40 milliamps with a spike when the clock rewind solenoid activates. Modern cars are usually higher, at least 50 milliamps due to memory refresh, electronic clock....


Also, Johnson controls "maintenance free" batteries and most others do use water, but at a much slower rate than the old maintenance type when our cars were new, so I remove the three-gang caps and add distilled water as required to top them off about once a year, and I believe this also helps me get very long life out of a basic inexpensive battery.

Duke

[Jeffrey S.]

Re: Battery charging procedure

I just replaced a 17 year old basic Johnson Controls fifty-dollar 26R battery that I actually killed stone dead twice over that period on a car that doesn't have a battery disconnect switch. It's parked for typically one to three weeks between drives. A day before I plan to use it I connect a conventional 2/6 amp charger on the 6 amp setting, and when the ammeter goes down to 2 I switch to the two amp setting and it goes to zero, which means it's fully charged. So it's on a car for an hour or two.

A typical "no maintenance" battery looses about one percent charge per day at room temperature due to internal leakage plus whatever load is on it due to clock, memory system refresh, alternator leakage... so after three weeks it's about 30 percent discharged. If you consistently demand cranking voltage at this level of charge it will sooner or later never come back to full charge due to a sort of "chemical memory", so if you want long battery life, always make sure the battery is fully charged before cranking. This isn't an issue on a daily driver, but IS on an occasional use car.


I don't think a constant trickle charger is a good idea. It's best to let the battery cycle a bit, but those so-called "float chargers" that detect voltage and turn the charger on periodically when voltage drops slightly due to discharge may be okay.

On a vintage Corvette the parked load is the clock and a slight leak path through the alternator, so a battery shut-off switch will eliminate those loads, but you will have to set the clock every time you drive assuming you want the time to be accurate.


Typical parked load on a vintage car is about 20-40 milliamps with a spike when the clock rewind solenoid activates. Modern cars are usually higher, at least 50 milliamps due to memory refresh, electronic clock....


Also, Johnson controls "maintenance free" batteries and most others do use water, but at a much slower rate than the old maintenance type when our cars were new, so I remove the three-gang caps and add distilled water as required to top them off about once a year, and I believe this also helps me get very long life out of a basic inexpensive battery.

Duke

There is a way to avoid the clock stopping and to be safe at the same time. Run a wire with an in-line 1/2 amp fuse from the negative cable mounting nut to the nut that secures the switch to the negative post. ANY draw except the clock will blow the fuse. I have used this in the past on the green knob type disconnect. Just don't get in the car and step on the brake peddle or the fuse will blow.
Jeff

[Terry M.]

Re: Battery charging procedure

Define: "while it is being charged"??

I want the battery to maintain the best possible charge between each occasional start up. The car is often parked for a couple of days at a time and at other times parked for 2 or 3 weeks without starting it.

As I mentioned the battery is new. I am looking to do what necessary to get the longest usable battery life.

What I was trying to get at -- and you have answered -- is whether you were looking for a maintainer charger; or if your battery needed a greater boost between drives. Perhaps I was reading more into your original post than you intended, but I didn't want to assume which situation you wanted addressed.

You have received the answer to your maintenance question from others.

The only addition I would make is to be sure the battery maintenance charger you buy has a fuse in the direct current side of it to limit the current draw. I prefer to place the maintainers I use on a metal surface and not on the body of the car. I have seen several pictures of Corvettes burnt by battery maintainers, but the brand used is not referenced in those internet posts. I think this is a place where product price should not be the first consideration. I have considered trying to limit the alternating current side of them as well, but I am not sure a small enough AC fuse or circuit breaker is available. More pressing issues have kept me from more fully exploring that area, but I throw it out there for public consideration.

[Jerome P.]

[Gerald C.]

Re: Battery charging procedure

My C2 is going into storage and I'd like to keep a Battery Tender on it. I also have a disconnect switch on the negative side of the battery. My question is....should I keep the battery connected through the engaged disconnect switch OR will the Battery Tender still charge the battery even if the disconnect switch is "off".

Thanks

[Jerome P.]

Re: Battery charging procedure

Connect the battery tender directly to the respective negative and positive battery posts. Or, and it is less work, connect the positive tender cable to the positive cable clamp at the battery and the negative tender cable to the side the disconnect switch is connected to the negative battery terminal.

[Wes S.]

Re: Battery charging procedure

Lead Acid batteries by chemistry need to be charged continuously. A maintainer will help extend the life of the battery. The newer maintenance free batteries are sealed valve regulated the valve keeps excess pressure from building up. The design requires a lower charging current, so the charging gas byproducts have the opportunity to recombine into water. Excess current causes the gases to be generated too rapidly opening the vent and allowing them to escape drying out the battery. With regard to disconnect switches I know of two C5 owners who had their homes struck by lightning. The surge went through the maintainer and took out the antilock brake control module. If a disconnect switch was used this would have been avoided.

[Gerald C.]

Re: Battery charging procedure

Do this with the disconnect switch engaged? If the answer is yes, that's what I do now.

Thanks