Odyssey AGM battery charging voltage

[sailorboy1]

I have a dockmate that has a pair of Odyssey 100AH house batteries. He asked me to take a look at the charging setup and help him understand them. I can tell the last owner of his boat was pretty technical and I felt everything looked good overall. The only thing I noticed was that all the charging sources seem to be set for 14.8V absorption. Even the main battery charger was set for LiPO instead of AGM which on his charger increased the voltage from 14.4 to 14.8. Sane thing on his alternator regulator, it was set to FLA but the voltages were also increased to 14.5V bulk and 14.8 absorption.

I looked up the Odyssey spec and it says to charge at 14.1-14.7 and not to exceed 15.

Is his setting of 14.8V going to cause any damage (my gut says it wouldn't)?

[john61ct]

Depends on which Odyssey line, I think not all the same?

And check ampages, I think some may want a .4C (40Amp) charge rate as minimum!

So double-check the chemistry and model are correct for the specs.

If so then best to follow the spec, even a little high over may impact longevity, with AGM can't replace gassing.

Flooded cells less of an impact, just keep topping up.

[ranger58sb]

This from the manual for PC-2150s (Group 31, probably the 100A batteries you mention), probably what you saw:

To fully charge a 31-PC2150 battery that is routinely discharged deeply, a minimum of 40 amps are required with charger voltage within the range of 14.1V to 14.7V. It is imperative not to exceed 15.0V as this will cause the pressure valves to open and out-gas hydrogen, oxygen and water from inside the battery. This will shorten the life of the battery and cause premature failure. Some portable chargers exceed 15.0V, especially two-wheel garage chargers, so charging voltages should be verified by measuring the charging voltage during the time when the charging amperage is reducing from full output. The deep cycle charging voltage must be within 14.1V minimum to 14.7V maximum.

I interpret that to mean 14.7V is fine, and would also suspect that means the closer he comes to that with sufficient amperage, the better he takes advantage of AGM acceptance rate. More than 14.7V, maybe not so great. Looks like he's in that no-man's-land area between 14.7-15.0V where vanilla Odyssey instructions are mute...

BTW, it also says 12.84V is fully charged.

FWIW, the closest I could come with preset profiles -- without exceeding 14.7V -- on our new inverter/charger is 14.6V bulk/13.7V float... seems to work fine. I could have chosen a 14.8V profile, but I didn't want to exceed 14.7, and the 14.8V associated float was only 13.3V. (The manual isn't forthcoming about best float voltage.)

Our oldest PC-2150s need replacing this year, but their 12 years old now...

On our charger, the settings are "named" probably according to whatever they thought might be close for a certain chemistry or type... but I suspect it's useful to pay more attention to the actual voltages in each profile, and then just use whichever comes closest to battery maker's guidelines. IOW, "flooded" or "LIPO" may not be all the important in the settings; the actual bulk and absorption voltages for a given profile (no matter its name) may be more closely match-able (?) to the specific target battery bank...

-Chris

[a64pilot]

Originally Posted by sailorboy1

it was set to FLA but the voltages were also increased to 14.5V bulk and 14.8 absorption.

This is the only thing that doesn't make sense to me, maybe you typed them in backwards? Bulk and absorption should be the same or at least absorption shouldn't be higher than bulk?
There really isn't any such thing as bulk, bulk is nothing more than absorption, but it is current limited, absorption begins when battery acceptance falls to a point that the charger is no longer current limited.

[john61ct]

You'd just want to check the actual output make sure it's not going to 14.9 or 15. and yes bulk should not be lower than abs, no harm but slower.

[HankOnthewater]

I got x4 P2150, not in the boat but in campervan, charged by solar and engine alternator, bulk charge has been 14.4 Volt, float of 13.7 Volt. Batteries are 5 years old, and in excellent health, and indeed resting voltage is still around 12.8 Volt.
Just installing inverter/charger, and when setting the voltages, I will use the ones as mentioned above I think. I certainly would not use higher than 14.7 Volt.

OK, now I should start saving to get all P2150 in my boat.........

[Sternwake]

I'd only get possibly concerned about 14.8v in hot ambient temperatures when deep cycling to the 50% range.

One can talk directly to Bruce Essig at Odyssey battery about it.

When I spoke with him 4+ years ago, he was adamant that incorrect float voltage for extended periods, and not meeting the 40% Minimums when deeply cycled to 50% or deeper, was more damaging than not meeting then holding for 4 hours, the exact 14.7v at 77F recommendation.

Technical questions should be directed to Bruce Essig at:
Tel: (660) 429-7506
Fax: (660) 429-1758
Send an email: bruce.essig@enersys.com

source:
ODYSSEY battery – Technical Information

[Cpt Pat]

Originally Posted by ranger42c

This from the manual for PC-2150s (Group 31, probably the 100A batteries you mention), probably what you saw:

To fully charge a 31-PC2150 battery that is routinely discharged deeply, a minimum of 40 amps are required with charger voltage within the range of 14.1V to 14.7V. It is imperative not to exceed 15.0V as this will cause the pressure valves to open and out-gas hydrogen, oxygen and water from inside the battery. This will shorten the life of the battery and cause premature failure. Some portable chargers exceed 15.0V, especially two-wheel garage chargers, so charging voltages should be verified by measuring the charging voltage during the time when the charging amperage is reducing from full output. The deep cycle charging voltage must be within 14.1V minimum to 14.7V maximum.

I interpret that to mean 14.7V is fine, and would also suspect that means the closer he comes to that with sufficient amperage, the better he takes advantage of AGM acceptance rate. More than 14.7V, maybe not so great. Looks like he's in that no-man's-land area between 14.7-15.0V where vanilla Odyssey instructions are mute...

BTW, it also says 12.84V is fully charged.

FWIW, the closest I could come with preset profiles -- without exceeding 14.7V -- on our new inverter/charger is 14.6V bulk/13.7V float... seems to work fine. I could have chosen a 14.8V profile, but I didn't want to exceed 14.7, and the 14.8V associated float was only 13.3V. (The manual isn't forthcoming about best float voltage.)

Our oldest PC-2150s need replacing this year, but their 12 years old now...

On our charger, the settings are "named" probably according to whatever they thought might be close for a certain chemistry or type... but I suspect it's useful to pay more attention to the actual voltages in each profile, and then just use whichever comes closest to battery maker's guidelines. IOW, "flooded" or "LIPO" may not be all the important in the settings; the actual bulk and absorption voltages for a given profile (no matter its name) may be more closely match-able (?) to the specific target battery bank...

-Chris

I just replaced my PC-2150s battery with a new one. It finally dropped to 80% capacity.

Time in service: 8.5 years

Cycles to about 50% SOC: 700 (about another 1,000 shallower partial cycles)

Absorption voltage: 14.7 volts (@ 25 degrees C - with temp. comp.)

Float voltage: 13.6 volts (@ 25 degrees C - with temp. comp.)

Maximum ambient temperature: 35 degrees C (NEVER put any lead/acid battery in an engine compartment!)

Minimum ambient temperature: 10 degrees C

Maximum charge current: 20 amps, variable lower currents when charging on photo voltaics underway.


The "minimum charge current" statements frequently seen are a myth. It's only important to return to 100% SOC as soon as possible.

I'm keeping the old battery to use in my home UPS. I expect to get another 2 to 5 years out of it.