Just checked how much a replacement battery would be for my greenline 2012

Over £200 for an agm battery are they really that much more advanced than a standard battery

I need a sit down ????

Believe that the agm is also for start stop technology? the cheapest I've seen them is around the £140 mark for a decent brand

Always find this spot best for batteries.

https://www.tayna.co.uk/096-AGM-Car-Batteries-G415.html

ABS batteries sell Normal/better than AGM ones for about £55 for the Octy. Ebay or Advanced Battery Services may also have cheaper AGM ones from what I can see a branded one is about £130

Have a look for Banner's Running Bull range.

AGM batteries are better than normal lead acid. They can put out more current in out go as they have a lower internal resistance compared to lead acid. Thats why car audio enthusiasts dont use lead acid nor do they use AGM leisure batteries.

AGM batteries can be very expensive. The XS Power I have in the front of my Octy is around the £250-£300 mark but you dont need anything that pricey.

https://www.tayna.co.uk/096-AGM-Banner-Running-Bull-Leakproof-Battery-57001-P8260.html

Edited 4 September, 20169 yr by ryan-re

Cars that have energy recovery and start stop need agm batteries. Agm have very significantly higher charge /discharge rate capability and can tolerate deep cycling. They also cope with a much more complex charge management strategy, which is needed for energy recovery (when you brake), and running ancillary items when stood which would kill a normal starter battery in no time.

You cannot replace agm with a standard battery in these vehicles. It would be dangerous to do so, as a higher charging voltage is used.

Do you have to programme the ecu to tell it a new agm battery has been fitted

Do you have to programme the ecu to tell it a new agm battery has been fitted

I believe that it might be so for more expensive cars but not as simple as Skoda.

Once I read an article about that. It said that most of the cars are able to understand that they got a new battery. They might act a bit weird few first minutes but should be fine after a short time.

Of course, dealers might say that it isn't true and you have to re-program your car by them for everything to be fine (for a little amount of money :)).

Do you have to programme the ecu to tell it a new agm battery has been fitted

 

 

No, a battery is a battery.

The battery technology wont make any difference to the car

Just checked how much a replacement battery would be for my greenline 2012

Over £200 for an agm battery are they really that much more advanced than a standard battery

I need a sit down ????

 

More advanced but also a lot more fragile in my experience...   I've had AGM batteries in my MX5 and after a few failures have swapped them out for standard lead acid.  In a low-use vehicle they can be a pain - they can't be charged like a normal lead acid battery (they generally need a slow trickle charge rather than a quick hit), don't like the cold and don't generally take kindly to being discharged and not kept topped up...

 

I'd be reluctant to use one again but then as you've pointed out some cars need them...

Afaik a genuine AGM battery cannot be topped up in the conventional sense, the electrolyte is held absorbed in the glass fibre matting. Agm batteries are very sensitive to overcharging, therefore the complex charging system on cars that use these.

Agm batteries should not be used on conventional non stop/non regen vehicles, they wont last long because their charging systems are incompatible.

More advanced but also a lot more fragile in my experience...   I've had AGM batteries in my MX5 and after a few failures have swapped them out for standard lead acid.  In a low-use vehicle they can be a pain - they can't be charged like a normal lead acid battery (they generally need a slow trickle charge rather than a quick hit), don't like the cold and don't generally take kindly to being discharged and not kept topped up...

 

I'd be reluctant to use one again but then as you've pointed out some cars need them...

 

If you do some research, AGM batteries perform a lot better in the cold than a lead acid battery and they also do better when discharged than a lead acid.

 

As Xman said, you shouldn't use AGM batteries in a car that does not have a battery management system as they will get overcharged and die. At various times the battery management system on an AGM battery will let the battery run lower than normal to cycle it which is the total opposite of what you want with a lead acid. This can also make testing the alternator more difficult as it will sometimes be running the car at a lower voltage so not to overcharge the battery

If you do some research, AGM batteries perform a lot better in the cold than a lead acid battery and they also do better when discharged than a lead acid.

 

As Xman said, you shouldn't use AGM batteries in a car that does not have a battery management system as they will get overcharged and die. At various times the battery management system on an AGM battery will let the battery run lower than normal to cycle it which is the total opposite of what you want with a lead acid. This can also make testing the alternator more difficult as it will sometimes be running the car at a lower voltage so not to overcharge the battery

 

The mk1 mx5 was fitted with an gel battery from the factory - a high spec Panasonic...   And was designed to suit this or AGM batteries...   So I have used one in a car designed for one...

 

However as I said my experience if them has been poor.  Yes they say that they are better in the cold and that they do better when discharged but as I said my personal experience of OE Panasonic and aftermarket Westco AGM batteries has not backed that up in any way shape or form, even when used with an AGM specific external charger.  I now have a Bosch lead acid in the boot and it is far better and easier to maintain.

Edited 5 September, 20169 yr by skomaz

The mk1 mx5 was fitted with an gel battery from the factory - a high spec Panasonic...   And was designed to suit this or AGM batteries...   So I have used one in a car designed for one...

 

However as I said my experience if them has been poor.  Yes they say that they are better in the cold and that they do better when discharged but as I said my personal experience of OE Panasonic and aftermarket Westco AGM batteries has not backed that up in any way shape or form, even when used with an AGM specific external charger.  I now have a Bosch lead acid in the boot and it is far better and easier to maintain.

 

The MX5 may have claimed to be designed for AGM batteries but its really not, there is no such technology in that model of MX5 to look after an AGM battery, the early MX-5's barely had any diagnostics never mind a battery management system. I once had to read faults from an MX-5 by using an LED in the diagnostic port and then try and figure out what the code was!! we are spoilt with OBD ports and VCDS 

Edited 5 September, 20169 yr by SuperbTWM

No, a battery is a battery.

The battery technology wont make any difference to the car

The absorbent glass mat type of battery is a different animal to a normal car battery in that it is very sensitive to maximum charge voltage in order that no significant gas is released. In UPS applications it is normal to vary the float charge voltage according to ambient temperature. They are valve regulated with a high pressure vent for safety.

The end of discharge voltage also has to be controlled closely to avoid reducing life.

The technology ends up costing about twice that of a flooded wet cell battery.

The agm/vr batteries come in application specific designs so whilst the technology may be the same, the versions for cars are not interchangeable for those in say, UPS or alarm systems.

Like most things in life, it's horses for courses.

You can use ups batteries in cars. Northstar nsb90/75/125 are ups batteries but work fine in a car.

Agm's do like a higher charge voltage but work perfectly fine off 14.4v rather than 14.7/8v which is what a lot of them prefer.

Reading above sounds like people have had a bad experience and written them off.

In reality agm batteries are far better. I personally have 2 agm batteries in my octavia working perfectly fine without any issues.

The whole discharge thing is a myth because no battery likes its voltage dropped down to very low, not just agm. In one of my cars when competing my voltage would drop to 10v but it didnt damage the battery.

The MX5 may have claimed to be designed for AGM batteries but its really not, there is no such technology in that model of MX5 to look after an AGM battery, the early MX-5's barely had any diagnostics never mind a battery management system. I once had to read faults from an MX-5 by using an LED in the diagnostic port and then try and figure out what the code was!! we are spoilt with OBD ports and VCDS 

 

The modern technology to cycle etc. batteries may not be present granted but the relevant charging voltages and current rates etc. are suitable and correct and the Westco AGM was supposedly designed specifically for the car.  The charger I used with them was also bought specifically to suit AGM / Gel batteries.

 

As for the diagnostics - yep - I've done that as well - I've had mine for 18 years!  But at least it is basic and easy to fix rather than the modern OBD / Canbus / comuputerised everything we get these days...

 

I'm not precious about it just talking from experience and my experience of them has been pretty poor...

 

I think the difference for me has been that in the winter when the car was garaged and lost some (bot no where near all) charge as it's not been hooked up to a maintainer it's died and not then wanted to charge again or recover, again using specific external charging kit.   I've never experienced that with a standard lead acid in over 30 years.  In fact I've had the opposite - standard batteries that have been tested and I've been told are junk have reconditioned OK and brought back to life.  I have one that is still going strong at 15 years old!

AGM and gel batteries are two different things. Do not confuse the two. If your car came with a gel battery, you cannot substitute it with an AGM because of the conventional charging system used with the gel battery.

Edited 6 September, 20169 yr by xman

AGM and gel batteries are two different things. Do not confuse the two. If your car came with a gel battery, you cannot substitute it with an AGM because of the conventional charging system used with the gel battery.

 

I'll bow to your apparently superior knowledge then - but my understanding was that the requirements for the OE gel were also suited to the AGM as they were more onerous than those for the AGM.

 

AGM replacements have been recommended by Mazda dealers and MX5 specialists for many years and many people have changed the MX5 battery from the OE Panasonic to the Westco AGM without issue.  Unfortunately I'm not one of them and have had issues so won't be buying another AGM battery, or recommending one, until I have to.

 

Hey ho - each to their own!

Skomaz, you do not need an agm battery BUT if you need a quicker discharge rate, or have a higher load on the electrical system they are ideal.

It wont be long that all cars are fitted with agm batteries. Its not a case of "I had a bad case so they are rubbish", thats just burring your head in the sand refusing the accept the truth that AGM is a far superior battery technology.

If they were that bad, why would people who have audio systems drawing thousands of amps in one go use and rely on them?


As for not being able to swap gel for agm xman.  Can you explain why? 
Gel hold their charge in a gel form hence the name and agm holds the acid in a glass mat. Gel doesnt give its power as fast as agm and overall is not as good in car applications. Charge wise they are very similar.

AGM batteries can take charge up to 14.8v but its unlikely you will see that unless its very cold.

Edited 6 September, 20169 yr by ryan-re

Did you manage to get a replacement battery? Mines on it's way out (varta agm 7P0 915 105 68ah) and I need to get a replacement but £200+ was a shock to the system. 

But I'll have to shell out if there's no other option. My car is a MK ll Superb 13 plate Stop/Start. 

Any advice much appreciated. 

Cheers.