Battery discharging?

[wingfoot]

While in storage I turn off the Battery disconnect to isolate the Battery, yet I am having a discharge problem..I thought this turned off everything and prevented an unwanted drain on the Battery. This does not seem to be the case. In as short a time as twenty-four hours my battery is showing on a "Fair" capacity level. There are no parasitic wires connected to the Battery..any ideas?

I failed to mention, this is a new Deep Cycle Battery (1).

Larry

 

[rebootsemi]

Are you sure the disconnect actually isolates the battery would be the first place I would look. Is the battery fully charged when you put it to bed? It takes a good while for the inverter to charge a deep cycle battery and you will get a fall off of battery condition. Lastly you could have a bad battery.

 

[wingfoot]

Are you sure the disconnect actually isolates the battery would be the first place I would look. Is the battery fully charged when you put it to bed? It takes a good while for the inverter to charge a deep cycle battery and you will get a fall off of battery condition. Lastly you could have a bad battery.

Thanks for the reply. I will have to say, I think my disconnect is working, because nothing in the coach requiring current will work..so I guess it's working as designed...

 

[Ray LeTourneau]

Wingfoot, I see your rig is a 2008. Is your battery the one that came with the rig? Normal life expectancy for a lead acid battery is 5 years. More realistically, in an RV, four. I would have your battery tested.

 

[rebootsemi]

Ray I believe he said it was a new battery, so now I go out and read and update the memory bank on batteries and how to test and such. Some great info in this link.

http://marine-electronics.net/techarticle/battery_faq/b_faq.htm#6

 

[TedS]

I'd suggest disconnecting either of the wires from the battery and see if the battery still discharges. That would verify if any parasitic loads are connected even when the battery disconnect is off.

 

[Ray LeTourneau]

Ray I believe he said it was a new battery, so now I go out and read and update the memory bank on batteries and how to test and such. Some great info in this link.

http://marine-electronics.net/techarticle/battery_faq/b_faq.htm#6

Oops, I missed that last line of the OP. Good link, thanks!

 

[Bob&Patty]

You could get a DVOM, disconnect either the positive or negitive cable and connect the leads between the cable and the battery. Set the meter for 12V amps and see if there is a drain on the battery. BUT...and it's big but....if there is not any other wires connected to the battery...then there cannot be a drain on the battery. Take the battery to a shop that can do a load test on it. If it fails the test...then the battery is KAPUT.

 

[wingfoot]

Thanks guys...good advice and a great link above.

 

[Bob&Patty]

OOOOOPS....should have said mili-amps. One thing to also remember. If a battery has, lets say, a 700 amp load rating. Then at a 1 amp draw,(1.0) on the meter, it would take 700 hours to drain the battery completely and so on. The only catch to that is, you will never be able to drain the battery completely. It just will not power anything up, well lets say at 200 amps. The voltage will be tooo low. Ya got to do the math after you find out how large the draw is. A normal dome light in a car draws about 2-3 amps. Hence, a dome light left on all night will drain a battery. The lights may still be on but there are not enough amps left to turn the starter. Most things that have a keep alive memory (Co2 monitors, radios, etc) only draw minimal amperage. Somewhere in the .005 amps range. The only things you are after is the 12V side of your coach. One other thing you can do is....disconnect the negative cable. Put a 12V test light between the cable and battery post. If you get a bright light...start pulling fuses. When pulling the fuses,one at a time, that turns off the light. Thats the circuit to trace the drain in. Hope you understand what I am saying.

 

[wingfoot]

I do Bob, and thanks sooooo much.
As a matter of fact, I took a screen shot of your post..this might should be a "Sticky"..

Larry

 

[caissiel]

I park 3 cars in the winter here and in the last 6 years I have been able to start them by the installed battery in each car after connecting the ground. I have away disconected the ground and have had the best results.

 

[Bob&Patty]

ALWAYS do as Laurent does. ALWAYS disconnect the negative cable first. If you disconnect the positive cable first you can cause sparking and arcing. Todays electronics dont like that at all. Most 12V electronics are protected on the ground side not the positive side from any voltage spikes. Doing it wrong can let all the "smoke" out of your pricey stuff. Ford stopped using the positive ground thing about 1954 or 55. The whole body of an old Ford was positive..."WHAT"? Remember "Ford has a better idea". Ever try to install a 12V negative ground wire harness in an old Ford and make the OEM dome light work??? While we are on the subject.....you can install a 12V battery in a 6 V car with out any problems except for gauges and radio's. Boy will it make the light bulbs bright.....should probably install 12V bulbs. BUT NEVER EVER install a 6V battery in a 12V system. Not only will you let all the smoke out of the wires...but probably burn the car to the ground. It's amperage that runs things ....not voltage. OHM's law is pretty cool once you understand it.

 

[Willym]

ALWAYS do as Laurent does. ALWAYS disconnect the negative cable first. If you disconnect the positive cable first you can cause sparking and arcing. Todays electronics dont like that at all. Most 12V electronics are protected on the ground side not the positive side from any voltage spikes. Doing it wrong can let all the "smoke" out of your pricey stuff. Ford stopped using the positive ground thing about 1954 or 55. The whole body of an old Ford was positive..."WHAT"? Remember "Ford has a better idea". Ever try to install a 12V negative ground wire harness in an old Ford and make the OEM dome light work??? While we are on the subject.....you can install a 12V battery in a 6 V car with out any problems except for gauges and radio's. Boy will it make the light bulbs bright.....should probably install 12V bulbs. BUT NEVER EVER install a 6V battery in a 12V system. Not only will you let all the smoke out of the wires...but probably burn the car to the ground. It's amperage that runs things ....not voltage. OHM's law is pretty cool once you understand it.

The real reason for disconnecting the ground wire has nothing to do with its polarity. Rather it is to minimize the risk of arcing, and personal injury should the tool you that you are using touch ground, i.e. the vehicle frame, while is is on the non-ground terminal. Voltage spiking and electronics protection is irrelevant.

 

[Bob&Patty]

Well I stand corrected. I guess all the engineers at GM are wrong about voltage spikes on their electronic's. I guess that all the years appling OMH's law to things and the training I recieved was all wrong. I guess my 47 years as a GM tech was wasted on wrong information. I guess Bill has never seen what hooking up a battery wrong or voltage spikes will do to the computors in a GM car or truck. Well I have, it was a new Cadillac and it poofed everyone of them to the tune of $1500.00 to the owner of the car. So again I stand "corrected".

Bill, you need not reply to this post....I feel insulted that you made look like an idiot to all the other posters. I try never insult anyone in print. Maybe you just had a "bad hair day". OH BTW, are you implying that all the info I gave the OP was wrong also??? As far as I'm concerned....it's case closed.

 

[wingfoot]

oooooops


Bob, still think your post should be a sticky...Thanks again for your valuable, I consider accurate, information.

 

[Willym]

Well I stand corrected. I guess all the engineers at GM are wrong about voltage spikes on their electronic's. I guess that all the years appling OMH's law to things and the training I recieved was all wrong. I guess my 47 years as a GM tech was wasted on wrong information. I guess Bill has never seen what hooking up a battery wrong or voltage spikes will do to the computors in a GM car or truck. Well I have, it was a new Cadillac and it poofed everyone of them to the tune of $1500.00 to the owner of the car. So again I stand "corrected".

Bill, you need not reply to this post....I feel insulted that you made look like an idiot to all the other posters. I try never insult anyone in print. Maybe you just had a "bad hair day". OH BTW, are you implying that all the info I gave the OP was wrong also??? As far as I'm concerned....it's case closed.

No intention to offend you Bob and with my amount of hair, it's hard to get a bad hair day, but I probably need to phrase my responses more carefully.
I was just pointing out the real safety reason for disconnecting the ground cable first, whether it be positive or negative. There have been many cases of people getting injured when putting tools on to the non-ground battery terminal - mainly on cars/trucks.
If there is a benefit to the electronics, then that is a bonus. I can understand reverse polarity causing damage to electronics for sure. However I need some more information on why it makes a difference to voltage spiking protection when the component sees the same potential difference no matter which side is reconnected/disconnected. Send me a PM if you like with more info on this.

 

[Duramax1]

While in storage I turn off the Battery disconnect to isolate the Battery, yet I am having a discharge problem..I thought this turned off everything and prevented an unwanted drain on the Battery. This does not seem to be the case. In as short a time as twenty-four hours my battery is showing on a "Fair" capacity level. There are no parasitic wires connected to the Battery..any ideas?
I failed to mention, this is a new Deep Cycle Battery (1).

Larry

After your battery shows a "fair" capacity level, how many hours do you charge the battery for?

You could be only partially recharging the battery which, when you disconnect it from the the charger, will show a full charge but this is only a surface charge.

If that is the case, it would naturally drop very quickly after you remove it from the charger.

 

[wingfoot]

Good point. I think what I'll do is make sure the battery has a full charge and then later, like the next day, check it with a digital meter to see if it has dropped much. If it has, I then will begin the parasitic loads test.

thanks again to all

 

[Bob&Patty]

OK Bill, my feathers are not ruffled anymore. You make a valid point and I guess I negleted to point out to the OP that is main reason to disconnect the negative cable first. And yes, I have arc welded a few screwdrivers and wrenches before. Another point that needs to be stressed is "NEVER EVER WEAR RINGS OR WATCHES WHEN WORKING ELECTRICAL DEVICES". Gold and silver are great conductors of electricity. You lite up a ring or watch on 6 or 12V batteries, your finger or wrist will be either gone from your body or turned into melted junk flesh. Seen that happen....you cannot get either one off fast enough to stop the damage.

The other point I was trying to make is. Most if not all 12V electronics are protected on the positive side from voltage spikes. Most up to 16V, however, most are not protected on the negative side. So draw your own conclusion on what could happen if something stupid happened.

Just trying to cover all bases with someone that might not be up on all the lastest info out there. Still all JMHO.