schneider XW inverter recharge volts setting?

new2PV

Hi just wondering where I should be setting my recharge volts at, just using flooded lead acid batteries. I just don;t know what would be best here, 70 SOC voltage for example from an online battery chart? Or should I add a bit more voltage above the chart voltage due to losses from the cables?

Blackcherry04

I usually start at 57.3 - 58.4v and 2 hrs absorb ( temperature compensated ) and adjust from there. You have 4-5 variables to work with. Voltage, time, current, ending amps, sun hrs and dod. With flooded batteries you have the SG level to adjust from. You don't have too reach 100% on every charge, but you should get there every 7-10 days at least.

More batteries die from undercharge than overcharge. Flooded Batteries come in a wide variety of different requirements.

The XW does not have EA ( ending amps ) as we know it with a shunt, it automatically uses the amp hr capacity setting or time to end absorb. You can fake it out by setting the battery capacity higher for longer time / lower EA or set the capacity lower for higher EA..

Configuration
3–12
975-0240-01-01
Absorption Stage Absorption charge is the second Stage of battery charging and provides the batteries a controlled, constant voltage. During this stage, the current supplied to the batteries slowly decreases. When this current falls below 2% of the battery capacity, or when the configurable Absorb Time expires, the charger switches to the Float or NoFloat stage, depending on the selected charge cycle.

new2PV

I think your talking about charge volts, which is also good info, but recharge volts is the point the charger comes on during discharge starting a new charge cycle.

Blackcherry04

new2PV wrote: »

I think your talking about charge volts, which is also good info, but recharge volts is the point the charger comes on during discharge starting a new charge cycle.

How low do you want to go ?? That becomes a function of available PV power adjusted seasonly. You could use a lower bulk voltage and try to do the absorb with PV power alone. Your standing voltage is about 50.5V with out load, so I'd think you'd want it lower than that.I'd test the system with average load and count the amp hrs out.

PV power is free, Grid and generator costs you, it'll take a couple months to sort it out and then as fall arrives, it'll all change. Keep notes, so you'll know what to do next year.

new2PV

I don;t know how low to go, but if I could eliminate the charger and just use pv that would be the best idea, but I don;t think I would have capacity to do that.

Blackcherry04

The problem with using voltage alone is that it's not a good indicator of true dod / soc unless the batteries are very healthy and have been equalized regularly so you know where the true 100% is. you can try around 49v and see if you can get back on a average solar day. Batteries do change over time, but once you know the big swings you can adjust for the PV's ability to recharge them.

new2PV

Supposed the new conext batery meter will help determine true SOC, but I won;t be able to do equalization on sealed batteries, so not sure how accurate this meter will be in real life. However a few members on this forum say its a good unit.

Blackcherry04

new2PV wrote:

just using flooded lead acid batteries.

new2PV wrote:

but I won;t be able to do equalization on sealed batteries,

One of these cannot be true.

A Battery Monitor's information is only as good as the Perimeter's you program into it. " Garbage in, Garbage out ".

new2PV

Blackcherry04 wrote: »

One of these cannot be true.

A Battery Monitor's information is only as good as the Perimeter's you program into it. " Garbage in, Garbage out ".

Both statements I made are true,i have maintenance free flooded lead acid batteries. You probably have a similar but smaller one in your car right now. The caps are glued on. However these are deep cycle designed for solar applications, but charging voltage must not provide gassing.

Blackcherry04

new2PV wrote: »

Both statements I made are true,i have maintenance free flooded lead acid batteries. You probably have a similar but smaller one in your car right now. The caps are glued on. However these are deep cycle designed for solar applications, but charging voltage must not provide gassing.

Then it is a " Sealed Lead Acid Battery " . If you cannot provide gassing voltage, gassing occurs between 13.9v and 14v ( 55.6v - 56v ), good luck with them.

new2PV

I will contact the manufacturer to get more info. They told me the float voltage is 57.2 so that would be higher than what your saying where gassing begins. Absolute max charge voltage is rated 60.8 volts. The XW default for equalization is 64 volts so I don' think that is a good idea.

vtmaps

A minor quibble... sealed acid batteries must be brought above gassing voltage and do produce gas. They use a catalyst to recombine the gas inside the battery. They are very sensitive to voltage... too far above the gassing voltage and more gas is produced than the catalyst can handle without overheating.

--vtMaps

Blackcherry04

vtmaps wrote: »

A minor quibble... sealed acid batteries must be brought above gassing voltage and do produce gas. They use a catalyst to recombine the gas inside the battery. They are very sensitive to voltage... too far above the gassing voltage and more gas is produced than the catalyst can handle without overheating.

--vtMaps

That would be my contention, I answered his quote.

However these are deep cycle designed for solar applications, but charging voltage must not provide gassing.

new2PV

Blackcherry04 wrote: »

That would be my contention, I answered his quote.

Sorry I should have said excessive gassing. Hey I am new to all this stuff, just here to learn, so i stand corrected.

Blackcherry04

new2PV wrote: »

Sorry I should have said excessive gassing. Hey I am new to all this stuff, just here to learn, so i stand corrected.

We're not chastising you, everyone wants to give you the correct information. To do that, we got to know what you got.

Vic

Believe that it is possible that new2's batteries are probably Flooded Lead-Calcium batteries. Believe that Lead Calcium batteries gas at a somewhat higher voltage and at a lower rate than do more traditional Lead Acid batteries. These batts may still really be Vented, but access to the vents is restricted by being glued shut ... guessing, but probably quite similar to automotive batteries, although, perhaps a form of Deep-Cycle battery.

vtmaps wrote: »

A minor quibble... sealed acid batteries must be brought above gassing voltage and do produce gas. They use a catalyst to recombine the gas inside the battery. They are very sensitive to voltage... too far above the gassing voltage and more gas is produced than the catalyst can handle without overheating.
--vtMaps

And, not to quibble excessively, but seems that there several types of VRLA/Sealed batteries;

AGM, Gel, and perhaps just Sealed batteries.

AGM batteries usually do have Catalyst, that recombines Hydrogen and Oxygen back into water. Absorb V about 14.3 V/12 V -- above Gassing
Gel, which are sealed, but often/usually have NO Catalyst. Absorb V about 13.7 V/12V -- generally considered below gassing.
Vabs approximations from Deka.

SLA -- Who knows, seems that these are generally Gel batteries, but manufacturers are often not too forthcoming.

A VRLA battery CAN recombine Hydrogen and Oxygen without Catalyst by allowing some amount of pressurization inside the battery ...

Am see FREQUENT "Error"s now, so will post this ... FWIW, YMMV, Pedantic Vic

new2PV

Thanks, Vic, but the batteries have 2 little holes at the end of the blanked caps. I can hear liquid moving when moving them. The float voltage seems high, or do lead -calcium batteries need more float I am not sure...

Vic

Hi new2,

Yes, agree with you, that these are Flooded, Maintenance-Free batteries, and that they are very similar to those that many of us use in our vehicles> Yours are 4D, considerably larger than our vehicle batts, and you are running the experiment of how they will do for your power system.

Meant to say before, that the Schneider term of "Recarge" is very ambiguous, as, technically, every charge cycle IS a recharge.

The Outback and Midnite CCs, andf perhaps even the old Xantrex SW Inverters call this second charge cycle in a day, " ReBulk ".

This second charge stage may not be needed at all, in your situation. Every charge cycle counts against the lifespan of the battery bank, and will cause additional heating of the battery.

If one really feels compelled to go into nighttime with the absolute fullest possible charge on their batteries, then, possibly a ReBulk is a good idea. As has been noted by BC04, IIRC, voltage is not a good measure of the current SOC of a battery, and hopefully that this parameter in the Schneider system would be temperature-compensated, at least, and possibly time-weighted.

Vic

new2PV

The battery monitor has a shunt and it determines SOC from the time the batteries were charged to where the amp hours run out from the bank size. It also has temperature in the system, I'm sure its added to the equation.