New Battery time...after eight years on this one

Fahrvegnugen

Veteran Member
Joined
Jan 21, 2017
Location
Burlington Vt
TDI
01 golf 1.9 alh gls silver
There is conflicting information and I’m glad i did the test. I don’t see many stories of an agm battery lasting as long as the one designed for the car. They need a different charge than what my car gave it.
I thought about getting rid of the battery cover and going with a bigger battery but I didn’t want any more experiments. I recall putting in the agm and turning on the car and frying my lights instantly. (It wasn’t the battery) but my New battery sat in 5 degree weather for 12 hours and started without a fuss. Also it frees up a little room in my battery tray so I can reinstall a hold down clamp and trickle charge without the hood open for snow to blow into the engine bay and cabin filter shorting out the blower fan when it’s -3 outside.
 

joetdi

Veteran Member
Joined
Mar 8, 2008
Location
Midwest
TDI
2-2002 Jettas W/Auto
dude, AGM's are BAD in cars. Great for flood lights and boat motors etc... but need to be charged with a SIN wave charger, not some cheep battery tender form china or your alternator in your car that uses step charge. .

Well , the new car I bought came with a AGM battery from the factory and it has a plain old alternator that charges it to, the same part number that is used on vehicles that use the old fashioned flooded battery. I don't have a SIN wave charger in my car.

AGM batteries have their purpose and one of the reasons is that these batteries produce little or no gas when being charged, so they are often used in vehicle that have the battery in the vehicle.(under the seat or in the trunk)

I have noticed the general life of these are not very impressive.
 

Mongler98

Top Post Dawg
Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
Well , the new car I bought came with a AGM battery from the factory and it has a plain old alternator that charges it to, the same part number that is used on vehicles that use the old fashioned flooded battery. I don't have a SIN wave charger in my car.
AGM batteries have their purpose and one of the reasons is that these batteries produce little or no gas when being charged, so they are often used in vehicle that have the battery in the vehicle.(under the seat or in the trunk)
I have noticed the general life of these are not very impressive.
How do you know what the charge curve looks like? (I might be using the "SIN charge" improperly.) I’m not an electrician. I’m talking about if you view the charging on a graph, you can have a "step charge" or a curve charge that looks like a SIN wave.
https://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html
Well, his is not a new car, and from all that I have read up on these AGM's is that you don’t want to charge them improperly. I’ve never had a car with an AGM, if that’s what it has, then that’s what you should use. I’m big into OEM.
That’s interesting and I’d like to know some more details as to some of the changed in how the electrical system handles its charge. You can charge most batteries (rechargeable) with any charging method you want, but if you do want the MAX life out of an AGM, you charge them properly (not with a step charge) and never drain them past 50%. I’m really big into fishing, have a few boats, and they ALL are electrical with cheap AGM's from amazon, 110 Amp hour. Run some MinKoda's and I can say that they are the way to go for this application. I’m just going off what I have had to discover for myself at battery and fishing forums. So I’d have to take your word on this one about the cars. If you have to put the bat in the cabin, it makes sense and seems to be the tradeoff. The shortest lived AGM I have ever had was 6 years of use every summer of about 450~ cycles.
From my understanding, AGM's are classified by things like Amp hours, and cycle life, vs a car battery that is more CCA.
I know it’s all calculated from the same basic numbers but eh, learned something new.
 

Ol'Rattler

Top Post Dawg
Joined
Jul 3, 2007
Location
PNA
TDI
2006 BRM Jetta
Dude, if you don't know what you're talking about, don't say anything. AGM batteries are just lead acid batteries with some fiberglass mat inside. They don't require sine wave chargers, lol. The rectified power from an automotive alternator charges them just swell.
But It's O.K. for you to talk when you don't have a clue what you are talking about? If I spout garbage, I fully expect to be called on it. Hense I always do my best to relate to things that have a basis in fact.

Fact. If your car came with a flooded cell battery, do not replace it with an AGM battery unless you are looking to pay more for sub standard service.
 
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turbobrick240

Top Post Dawg
Joined
Nov 18, 2014
Location
maine
TDI
2011 vw golf tdi(gone to greener pastures), 2001 ford f250 powerstroke
But It's O.K. for you to talk when you don't have a clue what you are talking about? If I spout garbage, I fully expect to be called on it. Hense I always do my best to relate to things that have a basis in fact.
Fact. If your car came with a flooded cell battery, do not replace it with an AGM battery unless you are looking to pay more for sub standard service.
Brother, you spout garbage all the time :). But you also know a few things and I respect that. I think you should go get one of Monglers sine wave battery chargers and put some electrons in your phased reluctance flux capacitor. :D
 

Slurry Pumper

Veteran Member
Joined
Sep 13, 2012
Location
Allentown PA
TDI
2010 Jetta Sedan
I hate to jump in on a forum fight, but my battery finally died Monday after 8 years. I knew it would happen sooner or later, but it was 3 degrees F ( also known as "Grape Nuts" on the nut scale for temperatures)Monday morning so I can't say I didn't expect it.

I also live just 3 miles from the East Penn manufacturing facility in Fleetwood, PA., so I went there for the replacement. I doubt that I will get the 8 years out of it, and given the high price of everything coming out of the VW dealer in terms of parts leads me to not support them when they have a reasonably priced battery even if it is a little better in the long run.
 

MikeS_18

Top Post Dawg
Joined
Feb 18, 2005
Location
Bow, NH
TDI
'03 Jetta Wagon, '13 Passat SE, '64 Ford Econoline
Well, your experience may vary but my AGM battery did go dead rather abruptly and probably about 18 months in. I took it back to OReilly after trying to charge it for a couple days and they couldn't get it to respond at all. They wanted to give me a full replacement and I asked if I could get a regular cell battery instead - took him a while to figure out how to replace with a less expensive product but we sorted it out. No more AGM for me - it was weird, one day fine, next day completely dead and unchargeable.
 
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