EFB, AGM Batteries: New, Conventional Wet Cell Options

Hello everyone!

After almost 8 years, the Audi A4 with that specific configuration needs a new battery.
As a huge MOLL fan, I got a M3 double-chamber battery in 2005, which was a better standard wet cell battery. However, it eventually failed due to lack of maintenance *my fault*.

Here's a short explanation for those interested: I generally prefer lead-acid batteries because you can significantly influence their lifespan through maintenance and care. Everything from the acid density, (visual) electrolyte and gas levels, to topping up the distilled water, is something you can control.
"However, I've had numerous very bad experiences with AGM and gel batteries in mopeds; at twice the initial price, there's simply nothing you can check or revive anymore."
So, I put another cheap, standard battery in my scooter, and it lasts at least twice as long as any other "super duper special" battery!
Back to case A4: Here, the excellent long-term test winner from MOLL definitely failed due to lack of maintenance, as the electrolyte level had not been checked for the past 4 years, and only then when it suddenly started to sound weak. All cells were completely discharged! All were refilled, charged, and re-breathed, and all recovered (almost perfectly!) except for one, which now seems to be conclusive.

Okay, a new one is needed.
Speaking of new developments, there's a new term: "EFB," which stands for "Enhanced Flooded Battery." This differs from a standard flooded cell in that the active material on the plates is coated with a polyester "scrim," which binds it to the plates, which are also thicker, under a slight mechanical pressure.
So, it's similar to AGM or remote GEL batteries, but you still have a nice (maintainable) electrolyte.
Developed primarily for start-stop vehicles WITHOUT regenerative braking!
Advantages: Minimum twice the cycle life, higher charging/discharging currents, high vibration resistance, etc.

AGM and GEL batteries fail due to higher charging voltages (often due to personal preferences or negative experiences) in my old Quattro. However, I'm very interested in EFB technology. The price difference is minimal (about 20 EUR), and if the advertised benefits are even remotely accurate, then the extra cost seems like a worthwhile investment.

The problem is that I can't find much information online about the electrical properties of these batteries. The manufacturers, such as Varta, MOLL, Banner, and Bosch, only describe the construction using the same standard diagrams, but they provide absolutely no information about charging voltage, required chargers or charging methods, or anything else.
The only thing that could be determined was that, in the long term, conventional wet cells would be replaced by EFB (Enhanced Flooded Battery) technology, as EFB offered advantages over wet cells, and the price difference was not significant – at least for major manufacturers.

Now, my question to you:
"Does anyone have any helpful links or documents regarding the electrical handling of these EFB (Engine Fire Bottles)?"

Sure, here's the translation:

"Thank you in advance!"

Best regards from Munich!

PS:
Varta: http://www.varta-automotive.de/index.php?id=380&L=1
MOLL: http://www.moll-batterien.de/produkte/startstop.html

Hello everyone!

I can already provide some answers to the open questions:
After sending an email to the technical support of MOLL, I unfortunately did not receive a written response, but instead, 3 hours later, I received a call from a knowledgeable expert .

Generally, EFBs (Enhanced Flooded Batteries) are comparable to lead-calcium batteries in terms of handling and charging.
This means that, as here, a slightly elevated charging voltage of approximately 14.4V (for AGM batteries: 14.8V!) is required to fully charge the battery, and this charging time must also be limited. Anything below 14.2V will inevitably lead to sulfation in the long term, which will cause premature battery failure because the battery will never be fully charged.
Therefore, lead-calcium or EFB (and AGM batteries are even worse!) are unsuitable for installation in older vehicles, where the voltage regulator aims to provide 13.8V-14V (all values are specified at 25°C).
"New" is that a constant trickle charge is counterproductive and can actually harm the battery more than it benefits. (The trend among car manufacturers is already towards temporarily switching off the generator, thus eliminating the need for trickle charging!) With the good old lead-acid batteries, a voltage of exactly 13.80V was applied (@20°C, otherwise adjusted based on temperature: -0.1V/0°C), and you could be confident for years that they would be fine.
It was also determined that EFB (Enhanced Flooded Battery) batteries receive the same acid as conventional lead-acid batteries, and that a density of 1.28 kg/L can be considered fully charged. This means that the internal condition of the battery can be assessed through acid density measurements.
ABär: Opening the cell stoppers always results in an immediate loss of warranty! However, it is possible to do so and, if necessary, add distilled water, as has been successfully done with lead-calcium batteries.

Summary: Based on the current state, EFB units don't seem to be able to easily replace all other types of bathrooms, even though they offer exclusive advantages.
Ah yes, there's a hidden disadvantage: The specified capacity relative to the physical size is often lower, because thicker plates and polyester require more space. However, they are more powerful in terms of cold-cranking current (regardless of whether it's DIN or EN standard), and in automotive applications, this cold-cranking performance is the only aspect of practical relevance.

Therefore, no EFB for my Quattro? ...that would be a shame, otherwise all the research would have been for nothing .

Best regards from Munich!

In my experience, it's a matter of belief.

I have seen expensive brand-name batteries die prematurely for no apparent reason, but on the other hand, I have also seen cheap batteries that lasted for 8 years or more.
Back when I had my Audi 90Q with a built-in heater, I paid a lot of money for expensive batteries.

"For example, I'm using a Panther P+ 85AH battery (a generic brand, supposedly not very good), which I bought for about 60 EUR almost 8 years ago. It's now nearing the end of its lifespan and will likely need to be replaced soon, especially if the temperature drops below -7°C."

DieselBear, thank you very much for the detailed information.
(Unfortunately, I can't give you a PlusKarma...)

I had to deal with the issue of the battery for my Passat about 1.5 months ago.
Due to frequent short trips and numerous electrical consumers, it started to show signs of weakness.
Despite the regenerative braking system

I was about to replace the batteries, but I'm not sure which ones to get, or which ones are better.

Ultimately, I invested the money in a good CTE... charger (also because of the summer car!), and sure enough, the Passat battery is working very well again .

I'll probably need to replace them before the next winter; these are still the original ones.
You've presented some really good information with thorough research.
Let me (us) know which EFB (Electronic Flight Bag) is going in there.

Best regards, Georg.

Hello everyone!

Autoservice wrote:

...in my experience, a matter of faith. ...

...a contradiction in itself

No, I wasn't interested in a comparison of different battery manufacturers, but rather in the background knowledge about the new EFB (Enhanced Flooded Battery) technology, which is becoming increasingly important.
Many, or rather almost all, now offer EFB (Extended Function Braking) systems in their programs, but they are not providing any background information about them. (According to the phone call I had with Mr. Bleischnüffler, this has something to do with the vehicle manufacturers!!! (although he didn't want to elaborate on the topic, even after I asked him further questions)).

Regarding the previous point, based on my experience, I can say that in my case, every battery is heavily stressed because of constant operation of the auxiliary heating system (even in summer!) before starting, sometimes long periods of inactivity (for months), and sometimes exclusively short trips, etc.
"I went through batteries one after another with that Eberspächer heater – despite excellent care! ... From cheap junk (FIAMM) to more expensive Varta (something or other), to what was then the top-of-the-line, the "black Bosch," they all simply wore out after 2-4 years... *frustrating!*"
Then I switched to MOLL batteries as original equipment in my A4, and they lasted for a long distance run from 1998 to 2005 under the exact conditions mentioned above. I was so impressed that I installed another MOLL battery (type: 83085, M3-K2, dry-charged and filled during installation), which lasted until now and would probably still last, if I hadn't skipped the regular checks of the electrolyte level. 5 out of 6 cells are still in very good condition, and the acid is perfectly clear!
Looking at the car battery test results of the past few years, MOLL has ALWAYS (!!!) been in first place! ...and that without much advertising, in stark contrast to Banner or A.rktT.U.'s, which apparently never invested in long-term durability but somewhere else . Bosch batteries have always been at the bottom of the rankings but are very competitively priced . Similarly with Varta, but the lead-calcium battery in the T5 as original equipment (manufactured in 2003) still holds up quite well (although it was unfortunately opened and water was added, as mentioned above).
Speaking of tests: My big mistake was always diligently having the battery levels checked annually during the initial inspection for the first few years, where there was never even the slightest indication that anything needed to be added. Therefore, I stopped doing it, but older lead-acid batteries are increasingly consuming more water, and those who stop paying attention to this are essentially fools and often become wiser later on.

As mentioned before, another battery from MOLL is going into the A4, specifically model 82080, which is an EFB (Enhanced Flooded Battery) with a capacity of 80Ah and a starting current of 800A. It's already here and waiting to be installed after the usual DBär inspection (charging, testing, cell voltage check, and terminal play). *g*
If it turned out to be a complete failure, I will continue to complain HERE .

Finally, a few notes on chargers and the general handling of lead-acid batteries:
(At this point, I will insert the wonderful link from Ulf here, which is very valuable!!!)
In my experience, it doesn't really matter what kind of charger you use. The only important thing is that the charging voltage doesn't exceed the specified limit (continuously), and that charging occurs regularly, even if it's not constant over days or weeks.
Regardless of the type, ALL batteries containing lead do not like being deeply discharged (i.e., discharged below a voltage of 10.5V), or to remain in that state for an extended period (even a few days is enough!), without being immediately recharged. It is also important to know that a traditional lead-acid battery loses approximately 1% of its charge per day due to self-discharge.
Therefore, even the best battery can be damaged from the beginning (due to sulfation, which is difficult to reverse), if it is purchased and installed from a hardware store after, for example, being stored for half a year without being recharged. In that case, even the best battery will be "bad" .

Best regards from Munich!

EDIT: Here's Ulf's battery article, which has some limitations regarding the term "valuable" .
/viewtopic.php?t=10964&highlight=battery

Quote:

Hello everyone! "Autoservice" wrote the following: ...in my experience, it's a matter of faith. ...a contradiction in itself. No, I wasn't talking about evaluating different battery manufacturers, but primarily about the background knowledge of the new EFB technology, which is becoming increasingly important.

A few lines further down:

Quote:

"I went through batteries one after another with that old Eberspächer heater – despite taking excellent care of them! From cheap junk (FIAMM) to more expensive Varta batteries (something or other), and even the then-top-of-the-line "black Bosch" batteries, they all simply wore out after 2-4 years... *frustrating!*" Then I switched to MOLL as the original equipment in my A4, which lasted for a long distance run from 1998 to 2005 under the exact conditions mentioned above. I was so impressed with it that I installed another MOLL (type: 83085, M3-K2, dry-charged and self-filled upon installation), which lasted until now and would probably still last, if I hadn't skipped the annual electrolyte level checks

.

Hi Uncle AutoSchrauBär!

Well, at my age, one is -still- adaptable in the way one communicates .

Best regards from Munich!

PS:

Sure, here's the translation:

"People can criticize me for it, but I generally buy the manufacturer's batteries."

So far, this has proven to be reliable; it lasted 180,000 km in the Ibiza and 220,000 km in the Skoda. However, this is only possible if you've received the significant discounts offered by dealerships.

Otherwise, I would have probably opted for the cheaper aftermarket solution.

Otherwise, I have consistently used MOLL products in former customer vehicles and among my friends, and I haven't received a single complaint during my active time.

Octavia_4x4 wrote:

Sure, go ahead and throw stones at me, but I generally buy the manufacturer's batteries.

They certainly aren't the best yet, because the manufacturer only knows one way: discounts and cheap prices! After all, contracts are made based on predictable quantities and prices.

Just as RED32 mentioned, VAG vehicles often have Moll/Vatra components installed.
Batteries have very little to do with mileage! It's more about their age, the number of times they've been charged/discharged, and the correct charging voltage used.
A good example: My neighbor's 90s Polo battery failed after almost 9 years - it was a Centro battery .

Octavia_4x4 wrote:

Sure, throw stones at me, but I generally buy the manufacturer's batteries.

And which ones? The originals or the cheaper "eco" version?

TDI-GTI-4-Motion wrote:

Octavia_4x4 wrote: People may stone me for this, but I generally buy the manufacturer's batteries. And which ones? The original ones or the cheaper "eco" version?

(The gentleman is complaining and enjoying it; it's not really silence ).

Hello everyone!

DieselBär30x wrote:

... It's already here and waiting to be installed after the DBär's initial inspection (loading, checking, cell levels, playfulness) *g* ...

In that sense, here's a brief update, because the aforementioned playful instinct is still going strong .
The EFB was manufactured according to the Polish stamp KW49/12 and was filled in KW51/12, delivered to my house via package delivery. It's practically as fresh as it gets .
What I always feared would happen with the shipment of open cells came true: The cell potentials were not equal, and acid must have migrated from some cells into the others during transport. (I would also be surprised if a package labeled "THIS SIDE UP!" was actually stored in that orientation throughout the entire journey from A to B .
Another striking observation was that, overall, there was "too little" acid in the battery. While opening the caps is prohibited (see above), the MOLL-brand plastic tongues, which serve as a minimum charge indicator, were all exposed, whereas in other MOLL battery types, they should normally be covered.
I then added almost 0.5L (!!!) of battery acid until the fill levels were satisfactory. However, I wasn't sure/am not sure if the plastic vents have the same function in this EFB battery and/or whether they should be filled accordingly. Therefore, I gave the battery a subsequent short, powerful overcharge to see if any acid would leak out due to extreme gassing - but it didn't, and still doesn't, so I think it's okay, or actually, there was simply too little acid in it from the factory .

By the way, the charging current for trickle charging drops to an actually unbelievable 40mA at 14.4V, which is an exceptionally fantastic value for an 80Ah battery.

It will be installed eventually, when there's time and inclination, or at the latest in February, because the vehicle inspection is due, and... it wouldn't look good to tell the inspector, while holding a jump starter cable, what a great, top-notch, and flawless vehicle you supposedly have.

Best regards from Munich!

Since our Polo's battery failed, I purchased a new one (Intact Racepower "RP50+" 50Ah / 520A, completely maintenance-free, not an EFB or AGM or any other modern type):

DieselBär30x wrote:

It was also noticeable that there was, overall, "too" (much) little acid in the battery. While opening the caps is forbidden (see above), the MOLL-typical plastic tabs, which serve as a minimum charge indicator, were all exposed, whereas in other MOLL types, they should normally be constantly covered... I then added almost 0.5L (!!!) of battery acid until the levels were correct... it turns out there was actually too little acid from the factory

. According to the manufacturer, the RP50+ should weigh 12.5 kg, but our scale only shows around 12 kg.
Surprisingly, the RP50+ battery has screw caps under the lid labels, which encourages traditional maintenance. So far, I've opened 2 caps and also noticed an unusually large amount of air between the top of the casing and the acid level, but the plates are well submerged. To reach the manufacturer's fill level, I could add about 1 cm of acid per cell (assuming they all have a similar "low" acid level).
I would even do that if it improves the battery function - and, for once, disregard the power-to-weight ratio .
However, I wonder if changing the mass ratios of active lead and acid per cell might not trigger some changes in the charging and discharging behavior, such that a battery with too much acid might not function as intended?

Quote:

By the way, the charging current for trickle charging drops to an actually unbelievable 40mA at 14.4V, which is more than a fantastic value for an 80Ah battery.

The Intact is now also being charged for several hours at 14.3V to compensate for the self-discharge in the dealer's warehouse. Let's see what remains as leakage current.

Edit:
In the meantime, I had opened all the cell stoppers. Even with the RRP50+, the acid levels differed overall by an estimated 5 mm, similar to how a trainee might fill batteries in a battery shop .
I initially adjusted the different acid levels using a titrator.

Even though the topic is no longer new.

If the EFB/AGM battery requires a slightly higher charging voltage, that's not a problem!

A voltage regulator with 14.8V costs only about 20€; just replace it and you're done.

I did that on my old A4 (may it rest in peace). One of the side effects was brighter H4 headlights.

Hi Garth!

DieselBär30x wrote:

... This means that, as here, a slightly elevated charging voltage of approximately 14.4V (for AGM: 14.8V!) is required to fully charge the battery, and this must also be time-limited. Anything below 14.2V will inevitably lead to sulfation in the long term, and consequently to premature battery failure, because the battery will never be fully charged. Therefore, lead-calcium or EFB (and AGM batteries are 10 times worse!) are unsuitable for installation in older vehicles, where the voltage regulator aims for 13.8V-14V (all values are -new- and referenced to 25°C). ...

...who can read exactly...

EFB is NOT AGM! EFB batteries would be overcharged at 14.8V.
But it's all already written down.

Best regards from Munich!

Hello everyone!

Brief update regarding:

DieselBär30x wrote:

...It was only possible to determine that, in the long term, conventional wet cells would be replaced by EFB batteries, as EFB batteries offered only advantages compared to wet cells, and the price difference was hardly significant - at least for the major manufacturers. ...

MOLL and other companies have completely switched to EFB (Enhanced Flooded Battery) technology for their hobby/solar battery lines. Therefore, there are no more "conventional" lead-acid batteries available in this product range.

And my EFB from above is still doing well - despite a complete deep discharge over approximately 2 weeks .

Best regards from Munich!