Mpp 800W 12V settings issues

Hopefully Ian is around or someone else can answer this question

I set my 01 to solar. My 12 setting to 12.8V. And 13 is default 13.5 V

My air pump is drawing 235W according to screen. Battery is down at 11.2 V from fully charged 13.5 at start. Pump is still running even though panels are only providing 35w on a no sunshine day.

My goal was to not drain battery only run when sun is providing the power to run pump.

Anything I can do?

after how long of running air pump does it take battery to drop to that voltage?

After a few minutes. It’s a brand new 100Ah 12V AGM
Battery cables are 4AWG. And 24” long.

Seems to be running ok when sun is out today saying 545W of solar and battery at 13.9V. Just concerned lower end voltage killing that battery. I did measure the battery at load and it’s the same as reported by screen so it’s not a voltage drop on the cable.

Any ideas?

Yep. This damn thing killing the battery. It was on running before daylight today.

This is a huge pain cause it’s a 5 hour drive each way to replace this.

NOT HAPPY.

Update. First let me say that Ian over at USA mpp solar is a hell of a guy. If you’re buying one of his units you get way better service for your money then the few dollars you might save buying from overseas. He has my business for my next 2.4kW project coming in the spring!

The MPP 800W 12 is really meant to supplement on grid with solar. I bought it because of Will Prowse review. I really should have asked more questions on the settings as I made too many assumptions as to their functionality without grid power.

Really the product when used as off grid only doesn’t work as more than and mpp charger and inverter. Most of the settings are for grid transfer and load sharing with grid.

For instance if you were using this in an RV without grid there isn’t a good way to stop the inverter before it runs the battery completely dead while you’re not watching (Choice between 10.5 and 12V shutdown)

I have this set in a remote spot in the mountains of WV connected to 750W solar array and 100Ah AGM battery. The load is a 1/4hp 120v air pump to keep my fish alive. However knowing the limits of the lead acid battery I really don’t want to cycle it more than 10-25% and let the oversized solar array do the 200W of work.

Ian came up with the ideas of using the dry contact relay included in the unit to drive my load. It’s up and working now and allowing me to use the grid transfer settings to power my pump and keep everything happy.

I will try tomorrow to load a video to YouTube for folks to see.

Thanks again to all you who keep this community going

I can vouch for Ian. I asked him if he could send me the newest/current update ( if there was one ) for the WatchPower and he did. V1.13SP3

https://usa-mpp-solar.com/manuals/Software/WatchPowerV1.13SP3(latest)/ ?

I'm not at all sure I agree with Denwa on this thousands use the MPP off grid. Just because there is a lot of on grid possible settings does not mean the MPP can't work perfectly with Battery/Solar only quite well. On "User" defined battery setting you can set the battery cut-off to any voltage you want, not just 10.5v or 12v. I added a Victron Battery Protect with my MPP. While it may be redundant, the Victron will reliably cut off my load at any voltage I select, with the MPP battery cut-off set just a bit lower in voltage to act as a backup cut-off. I have no problem with off grid MPP use.

DENWA said:

For instance if you were using this in an RV without grid there isn’t a good way to stop the inverter before it runs the battery completely dead while you’re not watching (Choice between 10.5 and 12V shutdown)

Click to expand...

Wouldn't a BMS with low voltage shutoff or a Victron Battery Protect save the battery?

Donald Siegel said:

I'm not at all sure I agree with Denwa on this thousands use the MPP off grid. Just because there is a lot of on grid possible settings does not mean the MPP can't work perfectly with Battery/Solar only quite well. On "User" defined battery setting you can set the battery cut-off to any voltage you want, not just 10.5v or 12v. I added a Victron Battery Protect with my MPP. While it may be redundant, the Victron will reliably cut off my load at any voltage I select, with the MPP battery cut-off set just a bit lower in voltage to act as a backup cut-off. I have no problem with off grid MPP use.

Click to expand...

what software do you have? Just to be sure what setting # are you refereeing to? I am talking about setting #29 its highest is 12V, which is dead for AGM

Woggs1 said:

Wouldn't a BMS with low voltage shutoff or a Victron Battery Protect save the battery?

Click to expand...

Then its really not an "ALL IN ONE" is it?

My review was honest about my experience. I still don't think this is well suited ALL IN ONE without grid power.

Denwa a 12v depth of discharge for a glass matt battery (AGM) is 50% a very safe discharge that is in the green part of the table for AGM (attached). A 12v load shut off will not kill your AGM. Its a safe depth of discharge that will maximize battery cycles. When under a load and you set the PIP to a 12v cutoff it will stop the load at 12v. Yet when you then see the actual battery voltage on your rested, no load battery it will read 12.4-12.5v so your never even getting down to 12v when you set the PIP cutoff there. Even if you really did go to 12v rested your fine. If your position is the PIP is not actually a stand alone off grid power station because the highest you can set the battery cut off is 12v it does not agree with the published dod tables for AGM. I really did not want to argue the details but would not want to leave the impression that the PIP has to always be on the grid. Mine is using gel off grid.

Donald Siegel said:

Denwa a 12v depth of discharge for a glass matt battery (AGM) is 50% a very safe discharge that is in the green part of the table for AGM (attached). A 12v load shut off will not kill your AGM. Its a safe depth of discharge that will maximize battery cycles. When under a load and you set the PIP to a 12v cutoff it will stop the load at 12v. Yet when you then see the actual battery voltage on your rested, no load battery it will read 12.4-12.5v so your never even getting down to 12v when you set the PIP cutoff there. Even if you really did go to 12v rested your fine. If your position is the PIP is not actually a stand alone off grid power station because the highest you can set the battery cut off is 12v it does not agree with the published dod tables for AGM. I really did not want to argue the details but would not want to leave the impression that the PIP has to always be on the grid. Mine is using gel off grid.

Click to expand...

Agree to disagree.

12V depth of discharge is too low in my opinion to start an RV or Boat in most cases.

My 20+ years experience in building lithium Ion 18650 cells says that chart isn't going to do AGM very well for cycle life.

Just my experience. Your mileage may vary.

BTW-- did you check your setting #29? seems like your had higher setting available?

#29 20-24v as it’s a 24v PIP.

We can agree lead acid battery life cycle is a curve so if you go only to say 30% DOD yes your battery lasts much longer. You will need more of them for fixed amount of energy usage as your drawing less energy per cycle so you’ll spend more on batteries to get there. You save in the long run as they last longer. Everyone needs to do their own math there. To get to a cut off voltage higher than the PIP allows you simply use a product like a Victron Battery Protect. They are as low as $40 and I trust Victrons gear. My batteries are the big investment. Few of us are trying to start RVs or Boats. PIP may not be top shelf, but it’s simple, for most works, and gets used off grid globally with good results. If you can’t start a boat with an AGM at 12v it does not follow that the PIP is useless as a off grid device. I think the horse is dead.

Donald Siegel said:

#29 20-24v as it’s a 24v PIP.

f you can’t start a boat with an AGM at 12v it does not follow that the PIP is useless as a off grid device. I think the horse is dead.

Click to expand...

Never said useless. Please re-read my post and edit yours accordingly.

I believe my review stands as my accurate experience with this device and its limitations as an ALL IN ONE.

I feel as if you have taken this personally.

Otherwise PM me and I'll send you my phone number and we can discuss this.

Thanks

Dennis