G'day all,

The batteries went completely flat the other night in the van. Two 105amp Lithiums of good quality. I found that there was a 15amp load showing on the Bluetooth but couldn't figure out where it was coming from. Today, I sent one battery to the tyre service for charging and put the generator on the other one. With all power turned on, there was no significant current draw all day. This evening however, all of a sudden a 15amp draw appeared. I started pulling fuses and as soon as I pulled the water pump the draw stopped. The water pump wasn't even on at the time.

Any suggestions? I'm at a loss as to why the pump would be pulling such power when the pump isn't even running.

Cheers, 

Ric

Has it seized & shorted.

No. It still runs without issue. Draw seems to be intermittent as well.

Thanks for the response.

Cheers.

No. It still runs without issue. Draw seems to be intermittent as well.

Thanks for the response.

Cheers.

Hi,

It would seem to be that the feed wire to the pump has been compromised somewhere - a pass through the chassis, or a flooring nail that pierced the wire, or a squeeze point getting too "squeezy" losing the insulation enough to give a partial short.

If you can't find the point you'll have to run new cable and swap the old one out.

Just make sure that the new cable is both protected and insulated, so that history doesn't repeat itself.

vanTas

It never ceases to amaze me how, based upon almost zero evidence, people arrive at conclusions of absolute certainty.

It is *possible* it's a cable short but unlikely. A cable short which drew 15A for an extended period and intermittently but never drew enough current to rupture the fuses would be unusual in the extreme.

When the fault is occurring is there any sound or vibration from the pump? If possible, place your hand on the pump body feeling for heat or vibration. Something which is consuming 180W is going to become warm to hot.

Also, during fault time, turn the pump on both to check if it works and whether that action stops the fault current.

Im just wondering because my pump will intermittently turn on after a while just for a second or two because of a very slow gradual drop in pressure in the line.  Im just wondering if yours is doing similar but the motor is sticking thereby drawing the current and then maybe freeing if you turn a tap on etc. and maybe that corrects the fault.

How many amps are these water pumps?

Fuse should only be about 50% extra. You can get panel circuit breakers from Jaycar up to 15amps.

Have used a 7.5 on my fridge & some smaller ones for smaller load accessories (Wire the load on the correct contact).

If you have one large fuse for a number of accessories it's asking for trouble.

Let us know the outcome please Ric as it may help others.

Good luck

Tim

Hi Ric,

It sounds like you have established that your water pumps are working ok.

Previously your monitor showed you had a 15A draw but this disappeared when you pulled to fuse for the water pump.  This could have been coincidence.

Now you have run each water pump separately and neither are showing a draw from your batteries.

So what are you using to monitor the current draw, your BMS or a shunt?

I?m going to take a punt and suggest you are using your BMS but forgive me if I?m wrong but here is what may be happening.

Two batteries = two BMS?s and you should be able to monitor any draw from each battery separately.  With two batteries the draw from each battery is approximately similar so with a water pump which has approximately 5A draw lets say 2.5A from each battery.  The problem is that some BMS?s are not sensitive enough to show a current draw below 3A so I may be wrong but this could be the reason why current draw is not being shown.  Try running both water pumps together and see what happens.

Of course the above does not explain why you are intermittently seeing the 15A draw but if you confirm it is being shown on your BMS and if it is whether it is on one or divided between both then we can look at whether your BMS is faulty.

Tim

Hi Tim, 

Thanks for your comments. I am monitoring the draw on the BluetoothSolar Controller. It is a brand new Renogy 60amp solar controller. I imagine the readings to be accurate because the batteries drained overnight. So far, all is good and both pumps working ok. I am constantly checking the phone to see the draw on the load to make sure all is OK. 

Cheers,

Ric

Hi Ric,

Well no wonder i dont punt .

I hadnt thought about the solar controller.  Are you are saying is that your pumps are connected to the load terminals of your solar controller and this is what you are monitoring? If so, what else do you have running off the load terminals?  

Is this a new system or an existing one that has developed a fault?

Tim

Just a passing thought:

I wonder if there is a poor connection (perhaps intermittent) somewhere on the pump(s) wiring or connections which is causing a voltage drop? If so it's possible the pump is seeing a voltage too low for it to run but high enough draw parasitic current?

Hi Tim,

I think everything runs through the Load controller of the Solar Controller. Nothing in the van works unless the Load is turned on. My understanding is that the Load terminals prevent the battery from being drained too low, although with today's smart lithium batteries they usually know when they've had enough anyway.

The Renogy controller is a brand new one I put in for the Lithium profile. The old controller would only work on AGMs.

Pumps still working perfectly, (although my wife says they are a little jumpy), and batteries still fully charged after 2 days.

Cheers, 

Ric

Hi Ric,

Yes, the solar controller has a low voltage disconnect and so does the BMS for the LiFePO4 batteries.

This all seems strange and as you previously stated the gremlins are at it.

Ok, two questions.

When you connected the solar controller the first time and the batteries after charging the second time, did you disconnect the solar panels from the controller, connect the batteries first and then the solar panels?  This is because you need to connect the solar controller to the batteries first and then the solar panels.  I have known some solar controllers do weird things if not done in the correct order and Renogy have specific instructions in the case of theirs.

If you can?t recall then i suggest you disconnect the solar panels, then disconnect the batteries then connect back up starting with the batteries.  Once you have done this then try running some loads to see if they register on the controller.

The reason I have raised this is firstly you said that your batteries went flat.  Then you said that it showed a 15A load when there was no load and finally it didnt show a load when you had two pumps running.  No punting for me on this one as I lost my money last time .

Here is the manual if you don't have it.  You should be able to see some very specific data according to the manual.

https://au.renogy.com/content/manual/RNG-CTRL-RVR60.Manual.pdf

The only other high current appliance that you may have would be a fridge so is your fridge also connected to your 12v system?

Im currently in France at the moment and that is why there is a delay in my response but hopefully someone else may be able to provide some possible answers.

Cheers

Tim

Hi Tim,

Yes, despite being a man, I did actually read the instructions for the Renogy and connected points in proper order. Everything still working well at this stage. As for the fridge, let's not talk about that. It has stopped working. Compressor and fan all clean and no problem. Replaced the thermostat but old one tested perfectly on multimeter anyway. This has been the most exciting trip ever for problems... LOL.

Cheers, 

Ric

Hi Ric,

Well glad it is all working but still cant see why there isnt a current draw showing when you have both pumps running.  Hope that you get your fridge sorted.

Tim