SBMS40 not starting

[Gordon Niessen]

Whether I pug in the 5x2 balancing cable or the usb power, the display lights up with only the first line "SMBS40" and does not have the initialization messages.  This happened after I disconnected the battery and top balanced it for a week.  I checked and verified all the balance leads are in the right order.  Not sure what would have happened.

[Dacian Todea]

Get the SBMS40 outside in the sun for a few hours so it can dry up. There is condensed humidity inside the SBMS40 shorting the real time crystal. Once it will be dried up it will all work correctly. 

[Gordon Niessen]

I had it inside for a day and it did startup finally.  But then gave a new error: "ISL94203 communication error","Before RAM read".

Then the Calibration ISL94203 was white bars, and the Calibration SDADC >>>>>>>>>>.  And it started in USB Power mode, even though nothing was connected to USB and the battery+ and balance cables were connected.

If this is a condensation issue, what can be done to avoid it?  Do I need to pull it apart and spray it with some kind of coating?

[Gordon Niessen]

Left it in the sun for a couple of hours.  It got nice and warm.  Brought it in and tried hooking to USB power and it still indicates the ISL94203 error.

[Dacian Todea]

Of course you will get ISL94203 error when powered by USB as the USB will not power the ISL94203.  That is very different from your initial error that was created by humidity.

You need to connect to a battery then there will be no ISL94203 error.

[Gordon Niessen]

Sounds like it has failed.  I get the same message when Battery + is connected and then the balancing plug.  Is it repairable?  Is it possible to get a replacement?

[Dacian Todea]

You probably removed the cell monitoring cable while a charger or Load was connected and that will damage the ISL94203 on the SBMS40
Repair is possible it will just mean the ISL94203 needs to be replaced.

[Gordon Niessen]

I am pretty sure I didn't do that.  I had not had a load attached for a day or more.  And had disconnected the solar connection early in the process.  I even had disconnect the wire, not just tripped the breaker.  It then sat idle for a couple weeks while I top balanced the battery.  And then only hooked up the Battery and balance cable.  But it does seem like the chip is now bad.  Who can I get to replace it?  Can I send it in for repair?

[Gordon Niessen]

Just to be clear.  I am willing to pay for the repair and shipping.

[Dacian Todea]

There are just two ways to damage the ISL94203. The most common is remove the 10pin cell monitoring cable while the PV or Load is connected to SBMS40

The other less common but it happened is to touch the XT1+ to battery+ (XT1+ is one of the temperature sense wire and some people connected a CAT5 cable and the wire from XT1+ touched usually the external shunt that is connected to battery+ and since this XT1+ is connected directly to ISL94203 pin and only capable of 1.8V the ISL94203 will get damaged).

No other way to damage the ISL94203.  So you you are sure you did not do any of this two things mentioned above it may be best to double check your connections and try to connect again. Make sure the USB cable is not connected at all.

So just connect the Batt+ to Battery+ and then insert the 10pin connector that is correctly connected to your battery.

It will not be great to send it to me an nothing to be wrong with the SBMS40.

[Gordon Niessen]

I have checked all the connections.  And checked them again. I have no XT+ connected.  I'll accept that I may have done it.  Just not sure how.  I'm not perfect.

I tried to connect another SBMS40, one from the remake Kickstarter (green).  No error on the ISL94203.  But cell 2 and 3 are too high.  My volt meter has all the cells with 0.02 volts.  Check the balance cable and it is all fine.  So the other one is messed up too.  And I have never had it connected to anything before.  Note: the cables connected to PV+ and Load+ are not connected to anything.

Am I just that unlucky?

[Dacian Todea]

I was not aware that you have that redesigned model of SBMS40. That was not built by me so I can not offer you repair for that model. If you have one of my SBMS40 then you can ship that to me and I will do a free repair.

The cells 2 and 3 seem to read 4.8V that is the limit the ISL94203 can measure so voltage may be even higher. But no idea how that will be possible. Do you have a photo of your battery to see the cell balancing connections ?

It is important that there is no fuse, breaker, switch (or anything else) between the Battery+ and SBMS40 Batt+ connection and same between the Battery+ and external current shunt.

[Gordon Niessen]

This issue is with one of your originals (see photo).  And I got one of the others as a spare.  And yes, I read the not on not having any break in the the Battery+ wire.  I can see why now.  I like your original design much better.  The other one cannot mount a heatsink or even mount to a board.

I'll have to photograph it tomorrow, when there is better lighting.  But I have gone pin by pin half a dozen times.  And the voltages are in proper sequence.

[Dacian Todea]

Was the intention to upload a different photo ? This one is the same as on the last post.

[Gordon Niessen]

Oops

[Dacian Todea]

Is this the exact same 10pin cable that is also inserted in the Green version of the SBMS40 ?
Have you tried to remove and reinsert again ?  If so and it still not working then you can ship to me and I will replace the ISL94203.