I picked up a on Prime Day for $65 to replace my old 3300 that was getting flaky (kept outside under my bumper year round for 7 years). The charger has an AGM mode, and can also go into AGM recondition mode. The documentation is pretty unclear, but from what I have read, while AGM Recon mode can be selected, it seems like it should not be used...

https://forums.ross-tech.com/index.php?threads/37328/

Just a heads up to anyone with an AGM battery using this charger!

 

My 2013 XJ came from the factory with an AGM battery, and I replaced the wet cell (flooded) battery in my XKR with an AGM battery several years ago. I use a CTEK MUS4.3 on both of them.

From CTEK

Recond program is developed only for flooded batteries (including EFB), to remix the flooded acid inside. The remixing/balancing is necessary to treat an already stratified battery, or to prevent severe stratification.

AGM or GEL batteries are not flooded, and therefore does not suffer from stratification. That means Recond will not help AGM or GEL. Reconding an AGM battery does not harm the battery, but does not help either, so we cannot recommend recond program on AGM batteries either.

For GEL batteries, recond can be harmful, because using too high voltage can dry the gel inside the battery and weaken the battery instead of empowering it.

NOTE:
When you choose Recond program, you should note that Recond program always starts with a normal battery charging program. Then, after battery has reached fully charged, Recond treatment itself is implemented. Depending of charger model and battery size, Recond step lasts from ½ to 4 hours, on top of the charging time.

When charger turns to green light, the program is completed.

I will explain here more about the topic:

So, Recond is made for remixing flooded acid inside the battery– hence, stratified batteries. What is stratification?

Stratification is when the acid inside the battery gets layered.
As long as the acid and the water of the electrolyte in the battery are well mixed, the battery works as it should. But if the acid and water separate into layers, the battery just cannot be charged anymore regarding the parts that are layered, not by the alternator, nor by a charger.

So, acid that gets layered inside a battery causes loss of capacity.WHY does the batteries get stratified?

Stratification can happen if the alternator charging voltage is too low or the charging time is insufficient (due to short drives for instance, or a lot of parallel loads during drive). Or if a battery is deeply discharged and unused for a period. Different batteries suffer more or less of stratification, depending of the battery type and qualifications. Why is stratification a problem?

A stratified battery cannot store voltage as well as a healthy battery, and behaves as a smaller battery than it is. When conventionally charged - by the charger or the alternator- only the parts that still are ok, will be charged. So, a battery seems to be fully charged – but can be emptied by one start attempt.
​​​​​
Stratification also promotes corrosion on the upper half of the plates and sulphation problems at the bottom. Why does recond help?

Recond causes a controlled gassing that remixes the acid and equalizes the acid balance and through that the battery capacity is reclaimed and battery efficiency is restored, partially or almost all of it, depending how severe the problem is.

Just one more thing: Do not mix Stratification with Sulphation problems! Sulphation affects all kind of lead/acid batteries AND every CTEK charging program starts with a desulphation step, so you do not have to worry about that!!

Hope this was helpful
Best regards,
CTEK SUPPORT TEAM

 

Thanks Stuart... while CTEK says it won't harm an AGM battery, most AGMs specify a 14.6v max charge rate, and the CTEK goes to 15.8v in recon mode... so probably best to avoid.

 

Positive-ly.

Sorry, couldn't resist the battery pun.