Battery charging issue

Battery Tender vs BMW Charger

From reading these threads I guess everyone is OK with using a Battery Tender rather than the recommended BMW charger. I remember reading in my owners manual a blurb about not using any type of charger other than a BMW model. Since I am new to BMW ownership I could use some advice on this. Thanks

qbrodie said:

From reading these threads I guess everyone is OK with using a Battery Tender rather than the recommended BMW charger. I remember reading in my owners manual a blurb about not using any type of charger other than a BMW model. Since I am new to BMW ownership I could use some advice on this. Thanks

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I've used a Battery Tender Junior plugged into my BMW Powerlet accessory plug for years. Bike is 12 years old and on its second gel battery.

qbrodie said:

From reading these threads I guess everyone is OK with using a Battery Tender rather than the recommended BMW charger. I remember reading in my owners manual a blurb about not using any type of charger other than a BMW model. Since I am new to BMW ownership I could use some advice on this. Thanks

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At the price point all these chargers are at (under $200), none of them are special in any way.

I like the CTEK 3300 for a couple of reasons. It has a motorcycle mode (14.3V @ 0.8A) for a slow charge, it has a car mode (14.3V @ 3.3A) and a cold mode (14.7V @ 3.3A), the latter when your vehicle is stored in sub-freezing temperatures.

I also have an Optimate III, but note that the charge rate is only 0.6A to 0.8A, so if you are trying to charge a battery, it will take a long while.

Stay away from the Harbor Freight Battery Maintainer. It is only a maintainer and to be used on a fully charged battery.

GlobalRider said:

At the price point all these chargers are at (under $200), none of them are special in any way.

I like the CTEK 3300 for a couple of reasons. It has a motorcycle mode (14.3V @ 0.8A) for a slow charge, it has a car mode (14.3V @ 3.3A) and a cold mode (14.7V @ 3.3A), the latter when your vehicle is stored in sub-freezing temperatures.

I also have an Optimate III, but note that the charge rate is only 0.6A to 0.8A, so if you are trying to charge a battery, it will take a long while.

Stay away from the Harbor Freight Battery Maintainer. It is only a maintainer and to be used on a fully charged battery.

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I got a CTEK too. I like it so much I carry it with me. I charged my auto I left my light on a bit ago, it multi tasks.

AGM batteries and chargers

I do know that my BatteryMINDer brought back "from the dead" my old Odyssey PC680, an AGM battery that "died", I thought. I had tried several other chargers on it without result. This charger has a "desulfator" cycle designed exactly for AGM's.

http://www.batteryminders.com/12v-charger-maintainer-sealed-agm-lead-acid-batteries

The old PC680 is now happily running a friends old R75-6. I had already bought a new PC680 before trying the BatteryMINDer on it, sadly, but that charger made a believer out of me after one night on the BatteryMINDer. The caps in the name are theirs, I guess to help prevent confusion with batteryTENDER. I have one of those that I tried to revive the PC680 with, too. Didn't do anything.

If your battery is an AGM (absorptive glass matt), sealed type, as most good motorcycle batteries are now, you might want to get this charger. It will charge my AGM better than the bike can. "Better" as in better for the battery. Don't take my word for it, do some research. Look up DESULFAtOR CHARGER CYCLE.

Also, their website has some very educational information about types of batteries, optimal charging rates, maintenance, etc for all types of batteries.

I got it on amazon for $90 USD. I am not affiliated with them except as a very satisfied customer.

For those that still prefer the FLA batteries, you might want to read about the advantages of AGM over FLA. I had a Plymouth Valiant with the push button automatic transmission and a slant six when I was young. It worked. But I moved on (upgraded). Just sayin....


Lowndes

lowndes said:

For those that still prefer the FLA batteries, you might want to read about the advantages of AGM over FLA.

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Unfortunately, the advantages of an AGM or GEL that do not even matter or apply, do not outweigh the disadvantages of an AGM or GEL.

But I am all ears. Tell me what those advantages are.

lowndes said:

For those that still prefer the FLA batteries, you might want to read about the advantages of AGM over FLA. I had a Plymouth Valiant with the push button automatic transmission and a slant six when I was young. It worked. But I moved on (upgraded). Just sayin....


Lowndes

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I used to have a rotary dial phone too.........

This, from batteryuniversity.com.

AGM has very low internal resistance, is capable to deliver high currents on demand and offers a relatively long service life, even when deep cycled. AGM is maintenance free, provides good electrical reliability and is lighter than the flooded lead acid type. While regular lead acid batteries need a topping charge every six months to prevent the buildup of sulfation, AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge.

The leading advantages of AGM are a charge that is up to five times faster than the flooded version, and the ability to deep cycle. AGM offers a depth-of-discharge of 80 percent; the flooded, on the other hand, is specified at 50 percent DoD to attain the same cycle life. The negatives are slightly lower specific energy and higher manufacturing costs than the flooded.

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roger 04 rt said:

This, from batteryuniversity.com.

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Exactly the advantages that do not matter.

• AGM has very low internal resistance, is capable to deliver high currents on demand - the original battery is fully capable of all starting requirements.
• offers a relatively long service life, even when deep cycled - well I guess if you are absent minded enough that you left your lights on and drained the battery, deep cycling might be important. As for long service life, that is pure BS and at double the cost of my FLA, the AGM would have to last 30 or more years, double the time I get from a FLA.
• AGM is maintenance free - no they're not, there is no such thing as a maintenance-free battery. They all need to be kept fully charged for a long life. And VRLA batteries (AGM and GEL) are not very forgiving to abuse such as over charging.
• AGM batteries are less prone to sulfation and can sit in storage for longer before a charge becomes necessary. The battery stands up well to low temperatures and has a low self-discharge - yes, they have far lower self-discharge rates, but who cares because our AGM batteries are not sitting on a dealer shelf....they are connected to our vehicles with electrical drains that are thousands of times higher than their self discharge rates. AGM batteries do not stand up well to high temperatures because they most likely get overcharged in those conditions.
• leading advantages of AGM are a charge that is up to five times faster than the flooded version - so would I need to do that when my FLA in my vehicle charged as required and lasted 15 and 16 years respectively.
• AGM offers a depth-of-discharge of 80 percent - and I need that why exactly? I'm not running a trolling motor or running in silent watch mode on the battlefield.

If AGMs are so reliable, why this pile of them after a very short life in the desert.

Jeff488 said:

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Also realize that when a battery is in a very discharged state (as in very low voltage), some battery chargers will not even work till the battery voltage is increased using a DC power supply.

WORKING WITH A DEAD BATTERY OR A BATTERY WITH A VERY LOW VOLTAGE:
If you try to charge a dead battery having a voltage below 3 Volts, the Battery Tender ® Plus charger will not start.
Source: Battery Tender

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And that voltage will vary from manufacturer to manufacturer.

So that will explain why some battery chargers do not work and some make it appear that they charged a sulphated battery. By the way, that battery probably wasn't sulphated at all, but simply highly discharged. I challenge any battery charger to fully recover a heavily sulphated battery.

I have no skin in this game.
Just watching the exchange of strongly held positions.
It's rather like an oil thread.

One would need some sort of emotion sounding bathyshere to plumb the depths of my indifference to the outcome.
I'm very sure no one cares what sort of battery I use, or why.

I bet somebody, somewhere, has wired together a bunch of D cells and made it work.

Jeff488 said:

Just watching the exchange of strongly held positions.

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By some with zero background. I spent years working in a defense lab with batteries and evaluating battery chargers, most of which promise you the world. After testing so many, I simply do not believe the text on the packaging without testing to verify manufacturers claims.

I have both Optimates and CTEKs at home. They are OK but nothing special. After running them on a data logger, one of them does not even do as claimed.

Jeff488 said:

Just watching the exchange of strongly held positions.

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The Avatar confirms this.

GSAddict said:

The Avatar confirms this.

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Sure, when you can't come up with any technical substance, pick on an avatar sold by Aerostich by the way, an American company. lol

Are you all talking about my avatar?

Definitely not sold nor designed by Aerostich.

GlobalRider said:

Sure, when you can't come up with any technical substance, pick on an avatar sold by Aerostich by the way, an American company. lol

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I don't care who sells it.
It's what it says. Racist & narrow minded IMO.
Japan makes some of the highest quality products in the world.

Jeff488 said:

Are you all talking about my avatar?

Definitely not sold nor designed by Aerostich.

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No

GlobalRider said:

...I have both Optimates and CTEKs at home. They are OK but nothing special. After running them on a data logger, one of them does not even do as claimed.

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Which one would that be and which claim(s) does it not meet?

My trusty old Battery Tender Plus is still going strong after 15+ years, but the voltage is a bit lower than the PC-680 would like, just like on my bike. I was leaning toward adding an Optimate 7 select to the garage as it can run a higher voltage and charge larger car & tractor batteries in much less time.

GSAddict said:

I don't care who sells it.
It's what it says. Racist & narrow minded IMO.
Japan makes some of the highest quality products in the world.

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