What does your FF voltmeter say? After starting and warming up it now settles down just under 13.5 volts. Each major mark is 1/2 volt. The reason I ask is my FF sat for a week and the battery was dead enough to not start the engine. I'm trying to see if the charging system is now a bit low or if one of the computers happened to discharge it. All was well after a bit of a charge although I could not get in the rear hatch because its computer was confused until after I drove it a few miles. With over 37,000 miles this never happened before. Battery was replaced a couple months ago for other reasons. Thanks, Rick
ours usually stays steady around 13.5+, I think 13.7 Odd your battery is down so much, given your new battery and heavy use. Testing the battery and charging system would be pretty easy, a trip to your dealer is obviously a hassle. If you have it charged up now and no further issues, I'd 1) assume fixed and 2) maybe keep the tender on it until checked
Rick mine is usually higher than that and have never seen it move Good luck and let us know as any new piece of information and or tips are always appreciated
Yep, if you normally watch water & oil temp like I do then push the display switch arrow to the right one click and you get a volt meter and oil pressure.
I use the tender that came with the FF, however I drive them too often usually to bother to put the tender on. This time it only sat six days, with possibly one or two extra starts to move from its normal garage spot to the wash bay and back. The factory tender has always worked well on my Cali. Rick
Rick, how long is your typical drive and in the past few weeks did that change and is your car a HELE model? For most cars, if your drives are short (less than 40 minutes or so) you are slowly discharging the battery. These cars have a ton of computers going all the time. The factory tender should do the job if you use it. I believe its a CTek 3300. Better would be to use its big brother, the 7002. I think it has more tending/ charging modes (its automatic).
I use mine almost daily and never use the battery tender unless I know the car will be unused for a couple of weeks. I've left it sitting for a week or so several times and it's started up without any issues at all. Starting from cold, the meter reads 12. As it warms up the meter slowly rises to 14.1, but once it's up to temperature, oddly, it decreases and settles at 13.4. Mine is still on the original battery. 25 months and approaching 13K miles. Strange that yours wouldn't start after only a week Rick. Mac.
My voltmeter reads exactly as yours does so I'm now guessing all is well. At 37,000+ miles now it obviously has not set long. I never used the tender, only on the Cali that I have in the winter as I usually only drive the Cali on nice top down days. I am sure that I let the FF sit longer than 6 days too but maybe not as the FF is more fun to drive. I will assume for the moment that maybe the computers were having a momentary tussle discharging the battery. In two years of ownership of the FF with similar driving style this has never happened. That is why I was looking for battery voltage from various FF owners to see if I had any abnormal indications, and there are none. Rick
Rick, your Cali uses a regular lead acid battery so any of the Fcar regular battery tenders would work OK on it. However, your FF uses an AGM battery like my HELE Cali30 and should use a CTEK tender that has the SNOWFLAKE/AGM symbol on it. You should only recharge the FF using the charger that came with the FF. The Cali charger won't fully recharge your FF's AGM battery. It also appears you did recharge the battery after it wouldn't start your car so I presume you got the 13.5V reading from your car AFTER the battery was fully recharged. If that is the case then the "low" voltage you saw in your car's voltmeter may simply reflect the temperature compensation applied by the car's charging system to supply a float charge. Charging voltage drops when it is hot - so as not to overheat the battery. Charging voltage goes up when it's cold, to charge faster and still not overheat the battery. Here's a handy AGM battery charging table I lifted from the Rolls Battery website. Notice it says 13.65V at 77°F (garage temperature) for a float voltage but only 13.53V at 86°F for the same? Your car's charging system probably measures engine compartment temperature. Temperature would be higher if the car is stationary. Image Unavailable, Please Login
Both my 458 and FF run in the mid 13 volt range, except after starting when they run slightly higher -- just about 14 volts or a little higher.
Rick- The two start and no drive cycles are probably what lowered the battery voltage below the start threshold. You would not think that would be a problem, but it can be. No idea why these systems were called 12V when they are acutally 14V systems. They got it right on 28V and 42V DC systems.
This is right. The usual number you hear is that 6-10 miles driving is needed to recharge the battery in a normal application. Also just because a car starts does not mean that the battery is in good shape. Lead-acid batteries do not like deep discharges and repeated long sits before starting your car will eventually catch up to them.
You guys may both be right ... its just that my driving habits have not changed a bit so I expected to see something else wrong. And with a battery that is only a couple months old as well. The previous battery was making a crackling sound in the radar detector along with firing electrical system failures. Lights seemed to be dimming more as well. All of that was fixed with a new battery. Rick
NO, is it really only 6-10 miles to restore the juice lost when cranking the motor? I thought it was more like 15-20 miles. Rick, a few months of shorter trips is what I would expect to cause the issue you had. For a DD, I wouldn't put it on a tender every day, but if your trips are indeed shorter, it might be worth while to make part of the parking and embarking routine.
The mileage needed to recharge the battery varies of course. As an example if you figure a starting cranking amperage of 500 amps and a 5 second start sequence, you will need to replace that 2500 amp-seconds over your driving cycle. If you alternator charges at 10 amps, it will recharge the battery in 2500/10 = 250 seconds, or about 4 minutes. To this you have to add the time needed to recharge the battery for the time the car just sat unused. A typical drainage rate is about 25 milliamperes, which for a week comes to 15,000 amp-seconds, a lot more than the discharge needed to start the car. As has been suggested, the problem could be repeated short trips in which the battery does not have time to fully recharge itself.
I rarely chime in but... The charging of a battery, capacitor or anything for that matter is related to current not voltage. If you really want to know the status of charging you need an amp meter. The meter will show current flow to the battery which initially should be high and then decrease as the battery charges. This assumes the engine is spinning fast enough to drive the alternater to produce maximum current. Voltage is an indirect measure of current as they are proportionally related by V=IR. Thus current goes up or down with voltage but current decreases as the resistance goes up. Temperature affects the resistance of circuits which at constant current will proportionally effect voltage. Amp meters are rarely used in cars these days. Voltmeters are more popular but have significant limitations. For example a high voltage reading in a. circuit with a wire fracture and thus high resistance would lead to low current and thus little if any charging. So, if you really want to know the status of your electrical system...
