[jonsobi]

Bought a brand new AGM from my local Ford dealer to add a a third battery to my soon to arrive Transit.

Just thought I would provide some feedback details.

The battery was dated 04/15. Would have preferred fresher, but dealer only orders them in batches of 25. Was told it was ready to go as Dealer does not charge them.

The initial voltage was 12.48, which is around a 75% SOC. That does not seem unusual for an AGM battery stored for 5 months.

I set it up to charge with my "3 stage" schumacher 15a charger set at the AGM option.

https://goo.gl/photos/4mdiUBXmvHNm1rJh7

It registered at 71% SOC. And started charging at 13v and slowly stepped up to 15.1v.

This was higher than I expected as I understood AGMs do not like higher than 14.4 or so bulk charge.

The voltage crept up and remained fairly constant at 15.49v. After about an hour, the charger showed the battery at 100% SOC, but was still putting in 15.5v. I stopped the process as I felt that was too high a voltage to sustain for too long on an AGM. So much for my "3 stage charger".

Can anyone out there suggest a reasonably priced proper 3 stage AGM charger that will put out proper voltages?

 

[lkruper]

Bought a brand new AGM from my local Ford dealer to add a a third battery to my soon to arrive Transit.

Just thought I would provide some feedback details.

The battery was dated 04/15. Would have preferred fresher, but dealer only orders them in batches of 25. Was told it was ready to go as Dealer does not charge them.

The initial voltage was 12.48, which is around a 75% SOC. That does not seem unusual for an AGM battery stored for 5 months.

I set it up to charge with my "3 stage" schumacher 15a charger set at the AGM option.

https://goo.gl/photos/4mdiUBXmvHNm1rJh7

It registered at 71% SOC. And started charging at 13v and slowly stepped up to 15.1v.

This was higher than I expected as I understood AGMs do not like higher than 14.4 or so bulk charge.

The voltage crept up and remained fairly constant at 15.49v. After about an hour, the charger showed the battery at 100% SOC, but was still putting in 15.5v. I stopped the process as I felt that was too high a voltage to sustain for too long on an AGM. So much for my "3 stage charger".

Can anyone out there suggest a reasonably priced proper 3 stage AGM charger that will put out proper voltages?

The best place to start is to find out if the manufacturer has a good user technical manual. Different manufacturers of AGM specify charging differently on occasion. What is the brand/model of battery you purchased?

 

[jonsobi]

Right out of the Ford Transit specs, BAGM-48H6-760 Motorcraft same as in the transit.

 

[lkruper]

Right out of the Ford Transit specs, BAGM-48H6-760 Motorcraft same as in the transit.

I could not find a traditional technical/user manual online for that battery. I did find a discussion where someone asked how to charge the battery and someone provided a link to an autocraft charger (http://shop.advanceautoparts.com/p/...tic+battery+charger&zoneAssigned=1#fragment-4)


I know that manufacturer-specific chargers are designed to work with their own batteries charge profiles, and don't know for sure if this particular autocraft is sized for your battery, but the manufacture should be able to answer that question with technical support.


I know that Odyssey AGM batteries have special charging requirements and that Sears sells them re-branded as their Platinum series and also chargers with a Platinum setting for that reason.

 

[jonsobi]

Tks for the link... There`s not much tech detail on that charger. It looks suspiciously like my 25 year old (ie, no microprocessor) charger.

 

[carnut]

...This was higher than I expected as I understood AGMs do not like higher than 14.4 or so bulk charge...

Everything I've read says that warning is for gel. AGM is not gel.

Gel is rare, mostly for high end applications where reserve capacity is more important than cost. And gel is not a good high current battery. You wouldn't want to use it for starting. Chargers for wheelchairs are supposed to be gel savy but I suspect they just use a gel profile for everything.

...The voltage crept up and remained fairly constant at 15.49v. After about an hour, the charger showed the battery at 100% SOC, but was still putting in 15.5v. I stopped the process as I felt that was too high a voltage to sustain for too long on an AGM. So much for my "3 stage charger".

Basic smart chargers are supposed to be constant current in bulk charge so voltage must adjust to keep current constant. Not sure why it ended at 15.5, but I don't think another brand wouldn't change anything. They all probably use the same controller chip.

 

[mindbend]

I have AGM batteries in all of my vehicles, from race-car to Transit 250. The NOCO Genius charger has been a rockstar. Does AGM, multiple-step, maintain, boost, etc. Check 'em out.

 

[jonsobi]

Tks for the tip. Do you by chance know the voltage outputs at the bulk and float stages?

 

[scorchen]

Tks for the tip. Do you by chance know the voltage outputs at the bulk and float stages?

Sorry for the thread bump almost 6 years later, but wondering if you ever figured out the charge voltage settings for the BAGM-48H6-760 stock AGM batteries?

 

[kazuo]

Just purchased a Costco (Interstate battery) AGM battery. Used a Battery tender 5 amp. charger to top up the battery. measured resting voltage 12.4 v. the charger started at about 13.0 v, when the charge was complete the charger was outputting 14.45 v. then the charger dropped to about 13.1 v float voltage. I don't recommend older non microprocessor controlled battery chargers when charging AGM batteries, they can work but you must monitor the voltage with a volt meter and disconnect when the voltage gets above 14.6 v, you cannot replenish the electrolyte in a AGM battery, and the higher voltage (15 v. plus) will deplete the electrolyte in a AGM battery. If you are going to play around with batteries you should have a dvm (digital voltage meter) even a $30.00 wallyworld version is more than adequate.