Wagan Pure Line 3000 Inverter Alarm when using Water Heater

[wanzong]

Hi,

I'm trying to troubleshoot a problem I'm having with the WaganTech Pure Line 3000 inverter.

The problem is that when I turn my water heater on (Bosch Tronic 3000T), the low voltage alarm beeping immediately starts up on the inverter. I tested this with a heat gun as well, and the same thing happens... the inverter alarm seems to kick in at around 1400 watts. I tested the heat gun in several receptacles with different wire runs back to the inverter.

Here is my setup:
- This is in a camper van (RAM Promaster 2500)
- I have two AGM 200ah batteries, fully charged (solar charging)
- I'm using 2/0 cable from the battery to the inverter (about 1.5 feet max run for positive with an inline switch, about 2 feet for negative... negative is going through a bus bar). See pictures below
- When I measure voltage at the inverter it shows the same that I see at the batteries
- My battery discharge monitor shows the wattage around 1400, amps around 115/116. This matches the water heater specs (1440 watts).
- Originally I had the positive running through a bus bar, and when I let the water heater run for about 5 or 10 minutes (with the inverter beeping the entire time), the inverter went into a fail mode. I noticed at that time the cable nearest the bus bar was hot to the touch. The cable near the inverter was warm, but not hot. That is when I went straight from the inverter to the battery switch (which did not stop the alarm).
- The 110/120 is run off the inverter's terminal block to a switch (shore power/inverter) then a receptacle and finally 15amp surge protector powerstrips.

I'm not sure where to go to continue troubleshooting...any help/tips would be appreciated!

Thanks!

Mike

[wanzong]

The pix didn't display for some reason... here are the links:

https://www.dropbox.com/s/9dmtreug7a...45.19.jpg?dl=0
https://www.dropbox.com/s/e4r1io0rdt...49.35.jpg?dl=0

[markopolo]

Two AGMs are probably not enough. Factoring inefficiency in, 130A to 140A needed at 12V to 11V. Each battery would have to supply up to 70A. Some batteries just won't be able to do that.

For that load, three batteries = 47A per battery or four batteries = 35A per battery would be much easier to reliably accomplish.

If there's adequately sized wiring, isolator / ACR etc. and fusing from the alternator to the house batteries then you could consider doing a quick test with the engine running to make sure the problem is the supply of power and not the inverter.

[wanzong]

Thanks for the quick reply and tips. I'll try running the engine to see that supplies enough power. I'll report back later this afternoon.

Thanks again!

Mike

[hbn7hj]

A lithium battery bank solves that problem. My 200ah of FLA doesn’t work as good as yours. I can’t run even a small inverter without an alarm.

[booster]

The OP stated he had two 200ah batteries, it appears, and they should be able to supply 130 amps. Our 440ah of AGM will without issue if they are fully charged especially.


Nomenclature issue? and two AGM batteries with 200ah total? That won't be enough to run long.


The other question that is always worth asking is how the "full battery" determination is being made. It is extremely common for that to not be the case unless a good monitor has determined it from correct settings. 85% is probably more typical.

[markopolo]

Good catch. Could be two 6V. Runtime & remaining capacity could be an issue as you noted.

[wanzong]

Hi all,

Thanks again for everyone's help! I'm still troubleshooting.

To clarify:
- We have two 200ah AGM 12 volt batteries (APX12-200, L6[12V200AH/20HR]).
- Other data on the battery (see linked pic):
x Constant Voltage Charge
x Cycle Use: 14.6 - 14.8V(25deg C)
x Standby Use: 13.6-13.8V(25deg C)
x Initial Current Less than 54A
- They are wired parallel for total of 12 volts, 400ah.
- By "Full" I mean my battery discharge gauge showed 14.6 volts when I started testing. They were down to about 13 volts after a few troubleshooting steps.

I did try running the engine while using the water heater... it helped quite a bit, but after about 10 minutes, the inverter alarm went on and almost immediately went into fail mode.

I also noticed that the microwave causes the same alarm when running over a minute or so (engine off). It draws about 1550 watts at full power. I tried a smaller microwave (1350 watts), it lasted a bit longer, but still triggered the alarm in under 2 minutes (engine off).

I am going to try to find another battery tomorrow and see if that helps per markopolo's suggestion. Question: what is important to match in a battery bank? 12 volts and AGM certainly. Amp Hours?

Thanks again for all this great input!

Mike

Pic of battery: https://www.dropbox.com/s/l7bnu40jn5...28.34.jpg?dl=0
Pic of battery discharge guage (no discharge at time of pic): https://www.dropbox.com/s/mo0c3pnrwo...08.56.jpg?dl=0

[wanzong]

Originally Posted by booster

The OP stated he had two 200ah batteries, it appears, and they should be able to supply 130 amps. Our 440ah of AGM will without issue if they are fully charged especially.

If the 400ah of AGM that we have (see last post) should be enough, then I'm back to square on on troubleshooting this. Any other tips? Is it worth trying another battery?

Thanks!!

Mike

[hbn7hj]

As mentioned before I could not make the FLA battery bank run much of anything without an inverter alarm. New batteries didn’t solve it. Fully charged batteries didn’t solve it.

A parallel lithium system will solve your problem. A replacement lithium system would, too.

I never did understand where my voltage drop was coming from but I was losing 1 volt at the TV through 10ft. of wiring with essentially no load. Paralleling the current path with 8 ga didn’t help. Never understood that. I even paralleled the ground line with 8 ga. I solved it with a voltage stabilizer which outputs 12.9 volts with inputs down to 9 volts.

I don’t know of a high current voltage stabilizer.

[markopolo]

They appear to be a UPS type battery so somewhat different characteristics than what's typically used in RV's. That said, the spec sheet indicates that they should handle the load. - http://www.apeximg.com/spec/APX12-200.pdf

Are you using a voltage sensitive relay (vsr) to separate the chassis battery and house batteries? If so, the VSR/ACR/Separator may open at 12.8V or so.

You could bypass the VSR/ACR/Separator for the engine running test.

Using lead acid batteries to heat water isn't very practical as Harry & Booster point out. If doing it daily then I'd expect short battery life. You'll have to somehow get them back to full daily IMO with that type of use.


Edit: just adding that engine assist is an option but I would use a DC to DC charger type device to limit what's taken from the alternator if it's done for regular use and not just testing.

[booster]

I am a bit confused about the full battery voltage of 14.6v you see. AFAIK, about the only way to see that high a voltage on a 12v nominal battery is when it is on charge. As soon as you disconnect from charge, it will drop to low 14s or so and then more slowly drop to it's true resting voltage over an hour or so. If the charger is being disconnected or taken to float as soon as it climbs to 14.6v, the batteries could still be quite low, depending on the charger size. Our 100 amp charger will be at 14.6v by the time the batteries are at 65-70% full.


A rested, off charge, no load AGM will more likely be in the 12.8-13.2v range depending on brand, age, and condition.

[wanzong]

Originally Posted by markopolo

Are you using a voltage sensitive relay (vsr) to separate the chassis battery and house batteries? If so, the VSR/ACR/Separator may open at 12.8V or so.

You could bypass the VSR/ACR/Separator for the engine running test.

We do have a KeyLine Chargers Pro Dual Battery Kit which is an isolator.

I'll try bypassing it and redo the engine running tests. I was wondering if that was shutting off the charging of the batteries after a period of time with load.

Thanks!

Mike

[wanzong]

Originally Posted by booster

I am a bit confused about the full battery voltage of 14.6v you see. AFAIK, about the only way to see that high a voltage on a 12v nominal battery is when it is on charge. As soon as you disconnect from charge, it will drop to low 14s or so and then more slowly drop to it's true resting voltage over an hour or so. If the charger is being disconnected or taken to float as soon as it climbs to 14.6v, the batteries could still be quite low, depending on the charger size. Our 100 amp charger will be at 14.6v by the time the batteries are at 65-70% full.


A rested, off charge, no load AGM will more likely be in the 12.8-13.2v range depending on brand, age, and condition.

My newbie-ness is showing here. I didn't realize this was how the battery voltage worked. The batteries are connected to a solar charger and are usually being charged (during the day). I'll shut off the solar charger for an hour or so and see what the voltage reading is then.

BTW these batteries are pretty new... we bought them in September (2020), installed them in October, and they have basically been just on the solar charger for the most part since then. We just finished the build, so we haven't really used it yet.

Thanks,

Mike

[booster]

Originally Posted by wanzong

My newbie-ness is showing here. I didn't realize this was how the battery voltage worked. The batteries are connected to a solar charger and are usually being charged (during the day). I'll shut off the solar charger for an hour or so and see what the voltage reading is then.

BTW these batteries are pretty new... we bought them in September (2020), installed them in October, and they have basically been just on the solar charger for the most part since then. We just finished the build, so we haven't really used it yet.

Thanks,

Mike

How much solar do you have on the van?


It is very possible, with only solar, that you have been walking down the state of charge with your testing at high amps. You could actually be quite low on the state of charge.



For a point of reference on a good and decently high sun day each 100 watts of solar will return maybe 30 amp hours of energy to the batteries.


At 120 amps you are using 2AH per minute. The last 20% of the battery charging to get to 100% will probably take over 6 hours and total charge times can be 10-12 hours depending on charger size and battery design.


Just charging with solar for high discharge times usually doesn't work out well. Many of use use big alternators if no shore power around for long term charging and then let the solar do long, slow, lower amp, charging to full.


Big battery systems of 400AH and higher can be much different than the smaller systems when you need to recover large amounts of energy every day or whenever the state of charge is low. It takes some big charging equipment and increased time.

[wanzong]

Originally Posted by booster

How much solar do you have on the van?

Hi Booster,

We have 3 200 watt panels for a total of 600 watts solar charging. We are using an MPPT 40amp charger (grape solar kit)

Pic of Solar Charger: https://www.dropbox.com/s/uw8tn4n5he...26.59.jpg?dl=0

I need to re-read your post a few times to absorb all that!

Mike

[booster]

That's a lot of solar which could give near 200AH per day in decent sun.


I looked at the user manual for the Grape solar 40 amp controler GS-MPPT-ZENITH to see how it operates and unfortunately it doesn't say much. Very surprised it does auto parameters for AGM, gel, and wet cells, but doesn't say what the parameters are.


It also doesn't say how it sets the charging times so have to assume it is from an algorithm. Solar chargers, in general, as very conservative on the charge times to prevent overchanging so probably would be stopping early rather than late for charging. It doesn't have any settable times at all.


Without know how they are determining when the batteries are full to trigger transition to float, it is very tough to know just how well it is charging, so your open voltage test is about all you will have unless you have a shunt based battery monitor, which IMO you certainly need in your system.


It will be interesting to see what you get for rested voltages.

[wanzong]

Originally Posted by booster

I looked at the user manual for the Grape solar 40 amp controler GS-MPPT-ZENITH to see how it operates and unfortunately it doesn't say much. Very surprised it does auto parameters for AGM, gel, and wet cells, but doesn't say what the parameters are.


It also doesn't say how it sets the charging times so have to assume it is from an algorithm. Solar chargers, in general, as very conservative on the charge times to prevent overchanging so probably would be stopping early rather than late for charging. It doesn't have any settable times at all.

Here are some screen shots from the app (PVChargePro) that shows the parameters being used (I think...not too familiar with the app). It's interesting that it's showing GEL. I'll take a look at the charger itself to see if that's the mode it's really in.

Realtime Status: https://www.dropbox.com/s/t3h3uoa433...41.36.png?dl=0
Parameters: https://www.dropbox.com/s/xfe3tjwhsz...42.10.png?dl=0
Device Info: https://www.dropbox.com/s/6aflym0wyu...42.25.png?dl=0

Originally Posted by booster

Without know how they are determining when the batteries are full to trigger transition to float, it is very tough to know just how well it is charging, so your open voltage test is about all you will have unless you have a shunt based battery monitor, which IMO you certainly need in your system.

My battery monitor is shunt based and is wired to monitor battery discharge.
https://www.amazon.com/Electricity-M...%2C228&sr=8-18

Originally Posted by booster

It will be interesting to see what you get for rested voltages.

Here are the results:
- with solar charging (mid-day, sunny all morning, full sun on panels): 14.33v
- right after turning off solar charging: 13.48v
- 40 minutes after turning off solar charging: 13.04v (seemed to have stabilized)
NOTE: The refrigerator was the only load on the battery, and was pulling about 3.34a for part of the time

With Solar: https://www.dropbox.com/s/i4z2ydanbb...56.25.jpg?dl=0
Right after turning solar off: https://www.dropbox.com/s/51skx4bclc...57.12.jpg?dl=0
About 40 minutes after turning off solar: https://www.dropbox.com/s/hu78ebcwzr...37.36.jpg?dl=0

[booster]

Originally Posted by wanzong

Here are some screen shots from the app (PVChargePro) that shows the parameters being used (I think...not too familiar with the app). It's interesting that it's showing GEL. I'll take a look at the charger itself to see if that's the mode it's really in.

Realtime Status: https://www.dropbox.com/s/t3h3uoa433...41.36.png?dl=0
Parameters: https://www.dropbox.com/s/xfe3tjwhsz...42.10.png?dl=0
Device Info: https://www.dropbox.com/s/6aflym0wyu...42.25.png?dl=0


My battery monitor is shunt based and is wired to monitor battery discharge.
https://www.amazon.com/Electricity-M...%2C228&sr=8-18


Here are the results:
- with solar charging (mid-day, sunny all morning, full sun on panels): 14.33v
- right after turning off solar charging: 13.48v
- 40 minutes after turning off solar charging: 13.04v (seemed to have stabilized)
NOTE: The refrigerator was the only load on the battery, and was pulling about 3.34a for part of the time

With Solar: https://www.dropbox.com/s/i4z2ydanbb...56.25.jpg?dl=0
Right after turning solar off: https://www.dropbox.com/s/51skx4bclc...57.12.jpg?dl=0
About 40 minutes after turning off solar: https://www.dropbox.com/s/hu78ebcwzr...37.36.jpg?dl=0

That voltage doesn't look too bad at all, but it might still go down some over more time. You should be quite full.


I hope you have the 300 amp shunt


That monitor will tell you decent instantaneous stuff, but not it will not keep track of power used or automatically determine if the batteries got full or not based on voltage and current to the batteries. A more sophisticated monitor would probably be in order as you have a big system and cost is not all that much compared to the rest of the setup. You would be able to set all the parameters to the right places to be able to tell if the solar is doing well, or not and also monitor your usage and state of charge. I am afraid without the better monitor, you are going to need to continuously watch yours to even begin to get a feel for what is going on. Everything gets much clearer once you can accumulate power in and out of the batteries over time.


The instructions for the solar controller indicated that if you programmed in the setting for lead acid batteries it would automatically set the right parameters for gel, AGM, or flooded. They must look at some charging characteristics. I don't know what it would display or what the choices would be to get to that auto setting, it might say gel for all three.


Would you be able to take your pix and download them to the site and post them that way? I quit Dropbox a long time ago when it got obvious they were looking at other areas of my computer and who knows what else.

[booster]

Just noticed that the monitor you have does count watt hours. Does it count both up and down when charging and discharging? Some don't count on the charge cycle and some do but don't have a charge efficiency setting for the charge side. I need to look and see if I can find a manual on it.