trickle charging how long?

[jsoto]

I have a AGM battery in our E53. Not sure whether the E70 comes stock with a standard lead battery or AGM.

Every 2 months or whenever I remember, I will put our chargers on it, mainly because AGM's are supposed to be charged up to 14.7 versus a traditional battery, 14.4. Whether those .3 volts is a big difference on whether these AGM's sulphate or not, I don't know. I just try to be proactive about it...

[Ron07x5]

E70 has a agm. For what I have read I am uncertain if a e70 can become discharged due to charging system design. As I understand it there is no voltage regulator always seeking to have the alternator top off the battery. Instead the alternator is only charging when coasting i.e. slowing to a stop or coasting down hill? So question if just short level trips are always done does battery overtime become fully discharged?

[Ron07x5]

It will be interesting if I discover x5 would become more and more discharged. There.is no question the alternator can charge the question when and if the computer software has the alternator charge. I believe.the software.design seems to minimize alternator use.to then improve epa gas mileage. But this is problematic if the x5 is used lightly?
We shall find out!

[London Lad]

Originally Posted by Ron07x5

It will be interesting if I discover x5 would become more and more discharged. There.is no question the alternator can charge the question when and if the computer software has the alternator charge. I believe.the software.design seems to minimize alternator use.to then improve epa gas mileage. But this is problematic if the x5 is used lightly?
We shall find out!

The system will only disengage the alternator under acceleration if the battery charge level is relatively high in the first place, if its low it will charge all the time. This cut off point is, IMHO, set to low and if the battery is older, or conditions arduous such as low temperatures, short runs or high demand, the battery can become discharged.

I used to find in the winter, running my remote diesel cabin heater could render the car unable to start, even though the heater is supposed to cut out if it detects low battery voltage or low fuel.

If I could I would code this function off as I think it's value to economy is pretty much zero and it's there just so BMW can claim to use wasted breaking energy. I have not been able to discover how to code it off or recalibrate it.

My solution has been to fit a 110ah battery and recode the car to suit. This has solved my problems and I now don't need to use a mains charger at all.

I stress this has worked for me in my particular usage patterns and may not be the answer for others.

[e30cabrio]

What tender charger is recommended for an AGM battery in a 4.4 e53?

[e30cabrio]

Thoughts?
NPower Automatic Battery Charger/Maintainer — 2/8/12 Amp Charge Rate, 12 Volt Batteries | Battery Chargers| Northern Tool + Equipment

[josiahg52]

Originally Posted by e30cabrio

What tender charger is recommended for an AGM battery in a 4.4 e53?

What type of AGM battery do you have in your E53 X5?

Originally Posted by e30cabrio

Thoughts?
NPower Automatic Battery Charger/Maintainer — 2/8/12 Amp Charge Rate, 12 Volt Batteries | Battery Chargers| Northern Tool + Equipment

That charger is good for recovering batteries that are severely discharged but not for continuous use.

[e30cabrio]

This from Autozone:
Duralast Platinum/Battery Price: $174.99
Core $15.00

• Part Number: H8-AGM
• Warranty: 3 YR
• Notes: *** 900 Cold cranking amps (1000 cranking amps)***. 160 / 95 reserve minutes. Warranty consists of 3 years free replacement. STOP!: Use a memory saver (located in the store GOTTChA kit) to prevent the need to reset vehicle systems. Battery is vented to outside of vehicle. Battery located in rear under spare tire.

[BMWOO7]

In the summer months, the X5 doesn't get driven as much as we drive our 650. With that said, it was about two-three weeks since my wife drove it into the office and back home (about 40 miles round trip).

I have the BMW trickle charger and had it on for about 1.5 days before it started to flash the Green LED & the Red LED, it then took about another 1/2 day for it to go Full Green LED and stay there.

This I have found is about average for the X5 as my 2011 was the same as my 2013 is.

As well, in the winter time when the 650 is in storage, I might take it out if we have a nice clean day (no road salt etc...) for a quick drive (maybe once a month at most) and it has always remained in a state where it will always start and no issues.

The only difference in my case anyway is that when the 650 is in storage it is locked, and the X5 is unlocked (I don't know if this makes any difference or not). I sometimes think that they use less power (draw) when they are locked.

Given all that I've also recently heard that BMW has started recommending replacing the battery at certain service intervals as they are just 'hard' on the battery.

The only battery issues I've ever had were with my 2011 335i Convertible. After about two years the battery would not hold a charge and BMW replaced it under warranty.

[Doug Huffman]

https://www.northerntool.com/shop/to...6185_200596185

NPowerXRP #60109 is what I have used on all of my batteries for some time - diesel tractor battery, sailboat battery, VW TDI diesel battery (gone to a new home) and now my X5 E70 35d N57.

I am not a battery expert. I was qualified to maintain a 126 cell TLX-39B capable of IIRC (40 years later) 1700 A 250 VDC nominal for 3 hours.

The #60109 specifies

Stage Seven - Float: Maintains the battery at 100% charge without overcharging or damaging the battery, allowing the unit to be left connected to the battery indefinitely. Ideal for batteries used intermittently such as seasonally used vehicles including classic car, motorcycles and RVs.

I cannot recommend BatteryUniversity.com too highly, particularly for non-experts.