Charging AGM vs FLA battery

[cho]

I have hybrid inverter with charging settings for AGM and FLA batteries.
I'm wondering what is differences between these two settings?
Also can you damage batteries if you charge with wrong setting?

 

[MisterSandals]

The AGM setting probably charges to around 14.5V and the FLA to about 13.5V.
Charging FLA with AGM setting will eventually cook your battery (boil off the acid inside).
Conversely, charging AGM with FLA will not fully charge your battery. It may also skip the periodic equalisation process.

All chargers are a little different to check the specs.

 

[cho]

Thank you MisterSandals
If you can tell me did I make some damage charging my FLA batteries (2 x 12V 260ah stationary battery) in period around two weeks with AGM settings?

 

[MisterSandals]

I dunno. Did they sit at full charge being continually with AGM charge settings? Did you notice any heat, bubbling noises or surfer smell?

If not, you are probably good to go. If they are still holding a charge in the 12.5V range you should be fine. If they drop below 12V quickly or on their own, it’s gone.

 

[time2roll]

AGM setting will mostly eliminate the equalize function. Bulk/absorption voltage is about the same with AGM probably a couple tenths lower.
Best to refer to the inverter manual and compare to the battery specs.

No damage to FLA in a couple weeks. Verify full charge with a hydrometer next time you think they are tip top 100% charged.

 

[cho]

Thank you for your answers.

I didn't notice any external changes (bubbling, heat, noise, smell). I also opened caps to check level of water and plates are covered with water about 1 cm.

I have one more question about differences in battery voltages when I measure with voltmeter.
When I measure voltages one battery has from 0.05 to 0.1 higher voltage. Is that normal?
Batteries is same manufacture and capacity.

 

[Texas-Mark]

FWIW, I have been running FLA and AGM in parallel for a few years with no issues. Max charge voltage I use is 14.1V which keeps both pretty happy.

 

[12VoltInstalls]

When I measure voltages one battery has from 0.05 to 0.1 higher voltage. Is that normal?

Chemistry. The static voltage you measure isn’t as critical as LiFePo voltages. So basically not a big concern with fla or agm at those variances.

How many batteries do you have; in series or parallel? If you have like 5 in parallel you can cross cable them for better performance or rotate them every six weeks. (mine always lose a tad more electrolyte volume on the outside two batteries so the batteries do ‘see’ their positions)

I'm wondering what is differences between these two settings?

FLA settings will (or should) weekly or biweekly equalize by charging to 15+ volts and ‘boost’ 13.8ish. This keeps fla happy.
AGM- if run through 15-16V equalize routines like fla, AGMs will be damaged.
Conversely, if FLA isn’t equalized regularly OR it doesn’t charge ~14V+ they will not have a very long lifespan.

 

[eXodus]

FLA settings will (or should) weekly or biweekly equalize by charging to 15+ volts and ‘boost’ 13.8ish. This keeps fla happy.

that will boil your batteries rather quickly. Why would you equalize that frequently?
I'm equalizing once a month - and get 6-10 years out of a set of 6V Golf Carts. Which get really deep discharged - no mercy people run them down till the cart goes super slow, less then 20% charge

 

[12VoltInstalls]

will boil your batteries rather quickly. Why would you equalize that frequently?

Hasn’t seemed to hurt…
My original P30L pwm did it automatically every week- or every ten days? Can’t remember now. Occasionally caught it at 16V+

The epever seems to do it every other week ? Automatically. 16+ volts. In good sun ‘normal’ boost I think I have set to 14.8 or something.

The current walmartha DC lead batteries are like in their third year and still going strong.

I don’t recall of the P30L was setable for equalize frequency but I’m pretty sure the AN40 doesn’t allow setting equalize frequency. I assume the epever automatically equalizes; I’m never here daytime very often and haven’t witnessed that.
But across my five batteries I don’t think I’ve used even close to a quart of distilled water in the last 12 months so I don’t appear to be boiling off water (which also would be assumed to mean the batteries aren’t stressed imho).

 

[eXodus]

But across my five batteries I don’t think I’ve used even close to a quart of distilled water in the last 12 months so I don’t appear to be boiling off water (which also would be assumed to mean the batteries aren’t stressed imho).

depends also on calendar age, The first 2-3 years they hardly loose anything. After that they start to need more water.

 

[12VoltInstalls]

After that they start to need more water.

Got it. So it’s not happening yet, been three years. If they started failing now I’d be disappointed but not entirely surprised but I don’t expect them to start showing weakness for a few more years based on past experiences. Time will tell.

 

[STW]

My RV has a Magnum MM1212 inverter/charger. The control panel it came with MM-RC is a simple on/off button. I spoke to Magnum and they told me it is set for AGM with no way to change unless you buy their advanced panel for a couple hundred $$$. I find it interesting that Fleetwood shipped the RV with that setup and install 2 6v GC2 batteries. It does not seem to hurt the batteries.

I monitored charging yesterday and in Absorb it was reading 14.62 volts. When it switches to Float it is at 13.5v. This is based on temperature as there is a sensor and it was 45 degrees out. When warmer the Absorb voltage is 14.3v.

Just keep an eye on the water level and you should be good.

 

[Kellie]

Also have a Magnum mm1212 inverter and just installed 2 - 12volt Lithium batteries. We have been using it as it was initially set up. Are we ruining our batteries by keeping the settings for lead acid batteries?? Can the mm1212 be set for lithium LifePo?? If it can how do I go about doing that? As you can tell I am very new to solar and all this. Thanks for any help I can get. Kellie