Xantrex XW6048 Bulk & Absorb voltages seem low

[SteveVk]

HI Guys

No matter if my Xantrax Inverter/charger is on Gen or solar it seems that the max voltage I see on the charge screen is 53.8v. The custom setting are
Bulk 58.8v
Absorb 58.8
Float 54.8

The batteries are used solidly overnight so I would expect it to go thru its cycles of voltages

Am I missing something


Thanks
Steve

[gmanInPA]

This is just a stab in the dark, but the Xantrex XW chargers are often temperature-compensated. I wonder if this might be adjusting your charge voltages? Do you have the BTS installed? Also... I find that some of my settings don't seem to "stick" unless I reboot the inverter. That's not always the case, but the software (at least the combox software) is wonky.

[gmanInPA]

Looking into this a bit further... if you don't have a BTS installed, this is how the XW inverter behave:

When the internal temperature of the Xantrex XW Series Inverter/Charger exceeds a preset limit, it begins to limit output power automatically to ensure maximum internal temperatures are not exceeded.

It does so based on the default battery temperature settings:

Default Batt Temp



Selects the battery temperature charging compensation if a battery temperature sensor is not installed. In the absence of a battery temperature sensor, the charger uses one of three settings: Cool (5 °C/41 °F), Warm (25 °C/77 °F), or Hot (40 °C/104 °F).

If you have the BTS installed, rather than using the default, it will of course use the BTS temperature.

This is where I'd look further to figure that out. If you don't have a BTS, it would probably be preferred over using a default temp - especially since that would need to otherwise change frequently. If you do have a BTS - this might be an expected behavior for your battery temperature. I believe those values are "not to exceed" values.

[SteveVk]

Thanks GmaninPa I'll check the BTS tomorrow, I think it does.. but if its attached close enough to the terminate to actually work I look at (I didn't do the install).. And a re boot. I was wondering if they have reasonable use (load) over night would I be better on a 2 stage cycle than 3?

[gmanInPA]

I have my XW's charger set to use 2 stage and my CC's set to use 3-stage - but I don't rely on my PV for the sole source of recharging, or even my generator - unless I am off-grid for long-enough to warrant so. If I recall correctly - If you do any grid sell, 2 stage appears to be the Schneider-recommended approach for the inverter's charger because otherwise it won't sell power unless the batteries have reached float - which can be a very long time. If you have an AGS installed, the triggers for such will determine much of how the generator works with the XW's charger.

Personally, I don't want my generator bringing my batteries to float - just to absorption or to a DoD around 95% - otherwise, the amount of fuel used is substantial, and usually unnecessary unless there is a long period without sun. If I were off-grid (or WHEN I am off-grid), I would continue to use the same setup I have now - though I'd probably attempt to follow the Smoke Model of charging outlined in the battery section.

If you're off-grid, the other off-grid folks here - especially those with XWs (ie Mike90250 I think) probably have more keen insights into the best settings for such.

[gmanInPA]

... but if its attached close enough to the terminate to actually work I look at (I didn't do the install)..

The BTS probes should be either directly on the terminal, or stuck to the sides of the battery using the included sticky tape. If you have Schneiders MPPT CC's, they should also have BT probes. I think the XW does also. If you have Schneider gear and connected via modbus, I believe you only need one probe for temp, and one for mid-point voltage. These could be easily relocated if necessary - assuming safely done.

[Mike90250]

I can't add much, I use the BTS. and have changed my set-points for my bank, the generator charges my NiFe bank up to 64V.

[Sunking]

The batteries are used solidly overnight so I would expect it to go thru its cycles of voltages

Am I missing something

Most likely you are missing something. Enough panel wattage and knowledge how batteries work. Just because you set a voltage point on a charger does not mean that is the voltage you are going to see. You will only see those voltages if the batteries actually get charged up to that voltage, otherwise they will always be lower. Why you asked. Because you do not have enough panel wattage to recharge your batteries.

As for the generator, I can only speculate you do not run your generator long enough to recharge the batteries.

Answer these simple questions.

1. Panel Wattage.
2. Controller make and model
3. Battery Capacity Amp Hours
4. Generator Size


In the meantime read:

Bulk, Absorb, Float Equalize
Killing Your Batteries

Lastly never use you equipment to measure voltages. Use your DMM.

[Sunking]

This is just a stab in the dark, but the Xantrex XW chargers are often temperature-compensated. I wonder if this might be adjusting your charge voltages? .

If that is the case, battery voltage set point goes higher in cold, not lower.

[gmanInPA]

Sunking - would you be open to doing any paid consultation/review of my system?

[Sunking]

Sunking - would you be open to doing any paid consultation/review of my system?

You do know I am in Panama right? Send me a PM with your email address.

[gmanInPA]

If that is the case, battery voltage set point goes higher in cold, not lower.

Ok, but if you had no BTS and a default setting of HOT or WARM in the inverter, wouldn't that lower the set point voltage?

[gmanInPA]

You do know I am in Panama right? Send me a PM with your email address.

I don't seem to be able to send people PMs in any way. It tells me to try logging in as someone else Sigh. If you have access to Skype or something similar, it doesn't matter to me where you're located .

[Sunking]

Ok, but if you had no BTS and a default setting of HOT or WARM in the inverter, wouldn't that lower the set point voltage?

yes it would. But I still suspect he just does not have enough panel wattage to recharge. Disable it and he will know. If he had a hydrometer he would know exactly what is going on.

[Sunking]

I don't seem to be able to send people PMs in any way. It tells me to try logging in as someone else Sigh. If you have access to Skype or something similar, it doesn't matter to me where you're located .

Crap I forgot PM do not work.