Disconnect Battery or Leave it Be?

[Conrad 16.5]

He's a follow-up to my OP:

To recap, I decided to just disconnect the battery (2 year old OEM), fill the tank to minimize the chance of condensation, and pumped the tires to 36 lbs. The vehicle was kept in an unheated garage in the cold north for all of Feb. and March if that matters.

Results:

• Reconnected the battery and it cranked just a tad slowly and stared right up. After driving 15 miles the start-up is back to normal with some battery recharge.
• I was surprised to see that my radio pre-sets and bluetooth setup were saved. The clock had to be reset, however.
• The tires lost 1/2 lb. at most with no detectable flat spots.
• On an initial 15 mile drive, the brakes started out sounding like like sh*t. The scratching / grinding sound is expected until rotor corrosion is worked off. What I did not expect was the whumpeta-whumpeta from the rear when braking. After a few hard stops there was noticeable improvement, then better from there, and now back to normal on the second short drive. Caliper sticking then unstuck with use? Self-adjustments made? Dunno, don't care at this point.
• I continue to maintain that claims of the PCM adjusting to driving habits are way overblown. The engine and transmission sound / feel / shift just as I had left it. The only other possible explanations are 1) the adjustment codes are stored in non-volatile memory (as with the PCM and evidently the radio presets) or 2) I've been driving to the Mazda engineers' benchmarks all along. If it's the former, disconnecting / reconnecting the battery will not fix any performance issue if one was of a mind to try it. And I doubt it's the latter.

As to the brake noise, did you put the car away with the brakes wet?

 

[181962]

As to the brake noise, did you put the car away with the brakes wet?

Possibly to some degree. I ran it through a car wash with an undercarriage wash then drove 4 miles home on dry roads with several stops. I don't see how that would matter much since it was sitting a garage after that. Are you suggesting I should have pulled the wheels and blow dried?

Frankly, with my most recent two Toyotas and a Honda, the brakes are/were a bit scratchy after sitting a week which is rectified after braking a couple of times. That strikes me as typical glazing of the rotors. The whumpety-whumpety in this Mazda was something new.

As for the question of a trickle charger, other than having to reset the clock it would have saved me no trouble.

 

[Conrad 16.5]

Possibly to some degree. I ran it through a car wash with an undercarriage wash then drove 4 miles home on dry roads with several stops. I don't see how that would matter much since it was sitting a garage after that. Are you suggesting I should have pulled the wheels and blow dried?

Frankly, with my most recent two Toyotas and a Honda, the brakes are/were a bit scratchy after sitting a week which is rectified after braking a couple of times. That strikes me as typical glazing of the rotors. The whumpety-whumpety in this Mazda was something new.

As for the question of a trickle charger, other than having to reset the clock it would have saved me no trouble.

4 miles with a stop or two should be sufficient to dry the brakes. I like to get them hot after a wash or before I put the car away wet.

"Are you suggesting I should have pulled the wheels and blow dried?"

Perhaps, but no need to remove the wheels. After a wash I always get my electric leaf blower out and dry off the car, including the wheels/brakes.

YMMV

 

[181962]

4 miles with a stop or two should be sufficient to dry the brakes. I like to get them hot after a wash or before I put the car away wet.

"Are you suggesting I should have pulled the wheels and blow dried?"

Perhaps, but no need to remove the wheels. After a wash I always get my electric leaf blower out and dry off the car, including the wheels/brakes.

YMMV

Drying with a leaf blower after a wash is a good tip.

 

[Conrad 16.5]

Drying with a leaf blower after a wash is a good tip.

My neighbors look at me like I'm crazy when they see me drying my cars this way but I've long since stopped worrying about what they think.

 

[hal2]

My neighbors look at me like I'm crazy when they see me drying my cars this way but I've long since stopped worrying about what they think.

And your neighbor's 3 year old car probably looks like a 10 year old car.

 

[Conrad 16.5]

And your neighbor's 3 year old car probably looks like a 10 year old car.

They always comment on how good my cars look and that they don't look their age. Yet, I still get the looks.

All my neighbors have garages but it seems that I'm the only one who actually uses the garage for cars. Most of them have too much junk in their garages to even think about parking the car inside.

 

[Tribe&TrueRacin]

probably disconnect the battery and keep it inside if you are worried and if its the oem one and if the car wont need to be driven for any reason. I would never leave a charger or even tender connected without supervision but thats me. My oem when left for 2months connected was ok-ish but it was severely drained at around 11.9. The car did start though. My current agm lasts 3mo connected without issues or big voltage drop but its deep cycle pure lead agm.
Up to your preference I guess.

I think you summed it up by saying "THATS JUST YOU" ?

soooooo when you leave for more then a day at your home you turn off the gas and also the main electrical breaker??

Most of the better battery tender on a full charged battery will cycle charge at less then 1 amp. The better ones have will shut off if for any reason they get hot. If something shorts I should hope your garage power out let is GFCI so all electrical power is shut off going to the battery tender.


I use NORCO Genisus and also a very inexpensive Power Charger tender from amazon. They work just fine and I feel totally safe using them for days, weeks and months on my batteries. I also have my motorcycles' connected to a battery tender solar charger.

I think if you check you would hard be pressed to find damaged homes or shops caused by a good battery tender and also you can call your local fire department or home and auto insurance and ask them their thoughts as well.

As far as how long any battery will last unattended, well that answer has way to many variables the least of them is the brand or type of battery being used.

 

[181962]

soooooo when you leave for more then a day at your home you turn off the gas and also the main electrical breaker??

The question at hand was about two months in February and March, not one day. Either way, given where I live, the furnace, fridge/freezer and sump pump need to stay functional. There are no alternatives.

Conversely, getting back to the OP, there were alternatives: 1) leave the battery connected for two months and risk volatile memory running it down to the point where the vehicle would not start, 2) disconnect the battery and possibly lose PCM codes, radio presets, etc., or 3) buy a trickle charger as many have noted.

Option 2) proved adequate at no cost or risk (however small a risk a trickle charger presents), with no adverse affects other than having to reset the clock. Others in similar circumstances might find that helpful.

PS: I do not go around and unplug the innumerable electronics around the house that draw some minimal power when in standby. Money can buy a lot of things and I gladly pay a few bucks in electricity to avoid that inconvenience. In power-off mode the chance of something catching fire is infinitesimal.

 

[Tribe&TrueRacin]

I really do not want to argue but let's be realistic about some things please. There is BIG difference in a battery tender and trickle charger....I didn't read anyone recommend that but I may have missed it?

Losing settings in any muti computer support vehicle is always a PIA. When I change any battery from such vehicles I use a supply power source so as not to disrupt electrical supplied components during the battery change . Loss of any PCM codes would mean a problem already existed and the check engine light was on, and disconnecting the battery will not remove the store code until it has been resolved. The monitors will stay in default until issue cleared and cycling was clear when the battery supply voltage has been returned.
Option 2 in the last response # 29 "no fault risk" , very untrue. There are a number of scenarios that could end up costing more to repair then to keep the battery charged up?

 

[181962]

I really do not want to argue but let's be realistic about some things please. There is BIG difference in a battery tender and trickle charger....I didn't read anyone recommend that but I may have missed it?

Losing settings in any muti computer support vehicle is always a PIA. When I change any battery from such vehicles I use a supply power source so as not to disrupt electrical supplied components during the battery change . Loss of any PCM codes would mean a problem already existed and the check engine light was on, and disconnecting the battery will not remove the store code until it has been resolved. The monitors will stay in default until issue cleared and cycling was clear when the battery supply voltage has been returned.
Option 2 in the last response # 29 "no fault risk" , very untrue. There are a number of scenarios that could end up costing more to repair then to keep the battery charged up?

I should have said battery tender if you prefer, but it is beside the point at hand.

It is my understanding that since the advent of fuel injection with computer controls, minor adjustments are made by and stored within the control systems based on engine performance that don't rise to the seriousness of a "trouble code" and idiot light, adjustments transparent to the driver. I regard these modifications as normal operating procedures and "codes" in the broader sense.

If trouble codes are not cleared when disconnecting the battery I would expect that normal adjustment "codes" are retained as well in some non-volatile memory. I come to this expectation with something as mundane as radio station presets in my vehicle were retained in what must be non-volatile memory. This was not the case in my previous 2006 Accord V6, for example, as respects at least normal operating "codes", as I was advised by a Honda tech, who said they should be fully restored after a couple of weeks of driving but otherwise no concerns. And of course radio pre-sets and the clock setting were lost as well,

Whatever problems might arise from disconnecting a battery (or having one go dead), I have not experienced them after reconnecting the battery after two months other than having to reset the clock. It drives the same as before and everything works. No idiot lights before and none after.

That was actually the primary purpose of the OP--What adverse affects might I encounter since electronics and computers have proliferated in the 14 years since that Accord rolled out of the factory? What I got was trickle charger recommendations. That's fine but I found it unnecessary.

 

[Tribe&TrueRacin]

May be off topic but I am simply lightly responding directly to one specific member which I will not quote to what I feel is for the most basically unusual information?
I will say looking on the WWW for a quick response is transparent to some that know by experienced and trained information.

No one would likely notice any ECU changes unless you connect via the OBDII diagnostic connector with a shop level scan tool with data logging capacities and run a data log and compare to a data log before the long-term power supply disconnect. ECUs are not AI (artificial intelligent) there are adaptive mappings in some ECU's, (not all) but they are very narrow maps in an ECU.
NO anomalies do not get stored up in an ECU in the idea mentioned in a response here on this thread. If there are unusual engine operation outside the factory engineered and designed mapping of the ECU then there are DTC like as an example often seen posted p0300 which is a generic DTC for anomalies of a undesignated engine ignition operation(s). The TCM and even ABS has as anomalous trouble codes as well these on various platforms. These anomalies diagnostic code numbers would alert trained auto technician to look at all possible causes. We tend to follow a tree of elimination to find the root cause of an anomalous DTC. These will also effect the monitors if the anomalies are not corrected which would have the monitors in a not state of readiness until the anomaly has been corrected and the cycles period run which can be several cold start to driving 50-75 miles a few times.

One of the latest responses the comments and conclusions about an ECU and how it works I found to be entertaining and sharing it with a few of us over coffee that offer and provide on a professional level EFI/ECU Performance calibrating ........we all smiled. I think some think that the current ECU in vehicle's are "supper computers"? It takes less then a minute to completely flash removing and replacing most ECU complete information using a pass-through tool.

Members on this forum will decide and do what they want on their personal vehicles' . Most will judge who really knows what they are talking about and also weigh their experience levels based on their information responses and perhaps even reading from historical responses.

I think I am pretty much over responding on this thread... In my opinion there is not much to add and it is starting to sway off topic and borderline against some of this forums responding guidelines (see #d. in rules) as I understand reading what they are.

At this point its like they say beating a dead horse.....or wanting the 1st prize of having the last

The term and original meaning "idiot light" was never designated for the yellow check engine (service soon operations) light. Think more RED indicators, red meaning DANGER!

Thanks for reading.....

 

[181962]

May be off topic but I am simply lightly responding directly to one specific member which I will not quote to what I feel is for the most basically unusual information?
I will say looking on the WWW for a quick response is transparent to some that know by experienced and trained information.

No one would likely notice any ECU changes unless you connect via the OBDII diagnostic connector with a shop level scan tool with data logging capacities and run a data log and compare to a data log before the long-term power supply disconnect. ECUs are not AI (artificial intelligent) there are adaptive mappings in some ECU's, (not all) but they are very narrow maps in an ECU.
NO anomalies do not get stored up in an ECU in the idea mentioned in a response here on this thread. If there are unusual engine operation outside the factory engineered and designed mapping of the ECU then there are DTC like as an example often seen posted p0300 which is a generic DTC for anomalies of a undesignated engine ignition operation(s). The TCM and even ABS has as anomalous trouble codes as well these on various platforms. These anomalies diagnostic code numbers would alert trained auto technician to look at all possible causes. We tend to follow a tree of elimination to find the root cause of an anomalous DTC. These will also effect the monitors if the anomalies are not corrected which would have the monitors in a not state of readiness until the anomaly has been corrected and the cycles period run which can be several cold start to driving 50-75 miles a few times.

One of the latest responses the comments and conclusions about an ECU and how it works I found to be entertaining and sharing it with a few of us over coffee that offer and provide on a professional level EFI/ECU Performance calibrating ........we all smiled. I think some think that the current ECU in vehicle's are "supper computers"? It takes less then a minute to completely flash removing and replacing most ECU complete information using a pass-through tool.

Members on this forum will decide and do what they want on their personal vehicles' . Most will judge who really knows what they are talking about and also weigh their experience levels based on their information responses and perhaps even reading from historical responses.

I think I am pretty much over responding on this thread... In my opinion there is not much to add and it is starting to sway off topic and borderline against some of this forums responding guidelines (see #d. in rules) as I understand reading what they are.

At this point its like they say beating a dead horse.....or wanting the 1st prize of having the last

The term and original meaning "idiot light" was never designated for the yellow check engine (service soon operations) light. Think more RED indicators, red meaning DANGER!

Thanks for reading.....

You were responding to me. Why not quote me? Anyway, let me translate your post from the layman's perspective.

You are saying that normal operating adjustments by the ECU are done real time, not stored for application on the next restart. Right? How simple would that have been? Or am I misreading you?

In your garbled response it is still not clear to me whether actual trouble codes are stored or whether they too would be regenerated in real time if the trouble is still detected at the next start-up, and if they are stored whether they are in non-volatile memory and retained if the battery is disconnected. That would be relevant information and on topic.

I'm well aware that vehicles do not come with supercomputers running AI. I'm also aware that AI is not "intelligent" in a meaningful way in the first place, but I digress.

You should keep in mind that most posters here are drivers not techs. Insight from techs is always welcome. Self-aggrandizement and snickering condescension "over coffee" or otherwise is never an attractive look.

 

[Antoine]

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Thread closed.