HOW TO: Check your Zamp Battery Temperature Sensor for proper operation

[John E Davies]

This is only for those with Solar; the Zamp controller uses a remote sensor attached to a battery terminal to determine the temperature so that it can decide how much current it should allow. You will need a digital volt/ ohm meter, a cup of hot water and a cup of ice water. The probe should be waterproof, but just in case, only submerge it so that the ring is under water.

I removed mine during a (major, in progress) battery cable mod - the factory had cut the probe cable and crudely spliced it back together, then covered it with sticky tape ;( I wanted to see if the sensor checked out before reattaching it again correctly. You can also go behind your controller in the cabin and unhook the two wires and test from there, but in any case you will need to remove the sensor from wherever it is attached. If you test from inside you will need a helper outside. Here is what mine looked like:

 

Zamp does not publish any specifications for this device, nor do they tell you exactly where to install it. An Amazon reviewer replaced his with a new defective one that was shorted out, and it fried his controller....! I suspect he installed it on a positive terminal. If the sensor is installed on a NEGATIVE terminal, and it shorts out, it will not apply power to the wrong components, it will just quit working. Or alternatively you can install it on the side of one of the battery cases using tape.

Zamp probe at Amazon

Using a digital voltmeter, check each wire (red and black) one at a time to see if they are isolated from the mounting ring- the meter should read infinity (open circuit). A shorted probe should be replaced, it will not function.

Next check the resistance between the pair of wires. This value changes with temperature. There may be a chart somewhere but it isn’t really needed. Mine read 13.7 Kilo ohms (13,700 ohms) when the garage temperature was 55 degrees F.
 

 

 

Carefully lower the probe into hot water. I used tap water at about 130 degrees F. After a minute or so it stabilized and the meter read 4.6 K ohms.

 

Lower it into ice water, the meter read 28.8 K ohms.

 

I hope this helps, I have not seen this discussed anywhere. If somebody finds an official Zamp temperature/ resistance chart for this probe, please let me know so I can add this information.

John Davies

Spokane WA

Edited June 15, 2020 by John E Davies

[mossemi]

What temperature value does the Zamp controller display during the test?

Mossey

Edited June 15, 2020 by mossemi
Typo

[John E Davies]

It didn’t display anything because it was not connected. My 12 volt electrical system is in pieces, literally and completely.  Here is what it will hopefully look like. This is just a foam mockup.
 

 

I don’t recall ever seeing a temperature displayed, so either mine is/ was dysfunctional or I was just too dumb to find the right button. I mostly leave it set on Amps. Is there a Menu option that must be selected for it to show battery temperature? Should I read the FM? pardon my foul acronym language.....

I will be sure to check it out when I can put power back on the trailer, which may be Tuesday. I am still waiting on parts.

John Davies

Spokane WA

 

 

 

Edited June 15, 2020 by John E Davies

[mossemi]

From the Zamp manual.

The mock up looks clean.

Mossey

Edited June 15, 2020 by mossemi

[Mainiac]

I have a message on the Zamp...604. 

How do I reset? What, and where can I test. Where are any fuses? Help!

[bhncb]

21 minutes ago, Mainiac said:

I have a message on the Zamp...604. 

How do I reset? What, and where can I test. Where are any fuses? Help!

IR thermometer would be good to have here.

First thing to do is pull the battery tray out and check the battery cases for abnormally high temp.

If nothings feels unusually warm/hot, check the negative battery terminal that has the zamp temp sensor connected to it. (This is the forward outer battery on my 2018 with the agm option)   If the 604 is valid (>65 degrees C ) you should not be able to touch it for very long. If hot, remove all charging sources and loads and disconnect batteries for test or replacement.

Next, assuming all battery temps seem normal (604 is false), pull the zamp controller out and disconnect the two temp sensor wires. The 604 error should clear and charging will resume. If this occurs, the temp sensor likely has a fault in the wire somewhere and the entire sensor will need to be replaced. If the error doesn't clear, the controller may be bad.

Not having the temp sensor hooked is okay just not optimal for charging.

[Mainiac]

Thanks. Will give it a try.

All batteries are cool.

[SeaDawg]

With the b04 error, they haven't been heating up with charging. The code should have shut down your charging.

After you remove the probe, and resume charging, I'd check again. For safeside. 

[Mainiac]

Probe removed. Batteries only at 4.5 v. Controller has NOT reset. Solar may be coming in at 18+ V. This is after two hours of full sun. Will give it more time. 

Still no call back from Service for second day...

[bhncb]

34 minutes ago, Mainiac said:

Probe removed. Batteries only at 4.5 v. Controller has NOT reset. Solar may be coming in at 18+ V. This is after two hours of full sun. Will give it more time. 

Still no call back from Service for second day...

The controller is supposed to go through a reset routine whenever it powers up. 18 volts from the panels sounds right but the batteries at 4.5 indicates probable shorted cell. Next step would be to test the batteries but this will probably just confirm what you already know. Depending on their age, it may be more expeditious to just replace them. In the meantime, best to darken your solar panels with a blanket and disconnect and insulate the wires from the controller SOLAR  terminals.

[Mainiac]

Actually ...I opened a ticket with Service. Jason replied almost immediately. I had already tested each battery, cleaned and treated each terminal.

Here is the proper way (abbreviated) to reset the panel: remove the panel from the wall. Disconnect the temp. probe (no longer used at the factory). Tape each of those wires separately and put inside. Disconnect the positive side of battery cable and temp tape it up. Disconnect the positive side of the solar cable (identified with the + symbol and the red tracer on the wire. Wait at least 5 minutes. Reconnect the solar plus cable, after removing the tape. Try not to double tap it as you put the screw back in. Viola! Panel came alive. Code 601 flashing ( no battery). Reconnect plus battery terminal. Yippie! It appears we are back in business. You do have to check to make sure the right battery type is showing as it will reset to a default AGM type. 

An aside: just as I hit a reply to Service that the procedure was successful, the phone rang and it was Mark from Service. Making sure we understood and checking in. Can't get any better service than that. Thank you Oliver factory and family...

[Mainiac]

Batteries have come up from 1/4 charged to 1/2 charged, and still climbing. It is tracking amp hours. Just went to 11.9 V, which is better than 4.5V. Whooho ...

[Mainiac]

Rainy, overcast day. Solar has still taken the batteries to 12.7V and 3\4 charged. ...