Monday, December 14, 2009


In the two seasons since I converted BIANKA to electric propulsion. I only had to make one repair on it. That was to the Xantrex XBM battery monitor and that was partly my fault involving it's installation and not because of a defect in the product. The battery monitor in an electric boat is an important device. About as important as a fuel gauge in other boats. It shows you a number of things but, most important is the current you are drawing from the battery bank when using the electric motor. For this reason I installed the XBM in the cockpit. As shown in the photo below:

This was a great location and it was where the original Westerbeke panel was located. The meter on the left shows the current the 48 volt wind generator is providing to the battery bank the XBM battery monitor on the right shows the wind generator current and a little extra that is being provided by the 48 volt solar panel. Those were happier times. When I was getting ready for the second season under electric propulsion I noticed that the display on the XBM seemed to be getting dimmer and harder to read. Finally by the end of June the display was totally unreadable and looked like this:

As you can see the display is completely unreadable. The digits appear to be all on. So I call Xantrex customer service and after a considerable time on hold I was connected to India I assume. I installed the the Xantrex the previous June and this was now the July of the following year. The warranty for the XBM was one year. So it was out of warranty. Ok that is a given. But, Xantrex has also discontinued this model too. Can I get it repaired? After all it appeared that only the display had a problem. No was the answer. Can I purchase a new display part. Again the answer was NO! The best I could get from Xantrex was a discount if I bought a new Link Pro unit. Not really an option at this point since my system was set up for the XBM monitor and had a prescaler built in for the 48 volts. In addition to spending several hundred dollars on a new link pro I would also have to by a new prescaler too. Now I don't expect things to last forever on board. But, I don't want to spend several hundred dollars on a new battery monitor after only a year. Still it looked like there was not much I could do about it. I went on line mostly to rant about not being able to get the XBM repaired. When someone posted that maybe I should try and contact a company in the Netherlands called TBS. BINGO! That was the key. It seems TBS actually makes the units for Xantrex. I told them my story about Xantrex not providing parts or servicing the XBM and asked if they have a new display that they could sell me. The answer was yes. It would cost me about 10 Euros ($15 U.S) but, I would need to do a wire transfer to the company account. Unfortunately, the wire transfer cost an addition $30 dollars but, it was still cheaper than paying $300 plus for a new battery monitor and prescaler. So the new display arrives and it's time to make the repair.

NOTE FROM CAPT. MIKE:I am making this repair because I have experience in repairing and working on small scale electronic systems and circuit boards. If you do not have experience in soldering and desoldering on electronic systems you probably would be better taking the unit to a qualified marine electronics shop for repair.

The first thing I needed to do is desolder and remove the wire terminal connectors from the back of the XBM.

You need to do this to remove the circuit board from the case. The photo below shows the circuit board after the terminals have been removed:

You then go to the display side and carefully remove the grey protective cover from the front of the unit (I also got a new one with the new display). You then remove the three screws holding the front cover to the case:

You can then slide out the circuit board. Here is what the circuit board looks like after it's been removed from the case. The LCD display is on the left:

There is not much that you will be able to fix on it because of it's complex and specialized integrated circuits. The display and maybe a defective switch is all even I would tackle on this unit. To remove the defective display I used an XACTO knife to cut through the leads at the base of the display.

The traces on the circuit board are very fragile and the area is very small . Trying to desolder the many leads of the display using a soldering iron will probably damage a number circuit board traces. So I cut the leads and removed the bad display that way.

I then used the tip of the soldering iron to remove the remain pieces of leads that were attached to the circuit board traces.

After a little cleanup of the circuit board traces it's time to install the new display:

The defective display is on the left. The new display has a protective film that is removed before operation. the display also comes with a new protective panel which is at the top of the photo. Here is the new display mounted onto the circuit board.

All that is needed is to reassemble the unit including resoldering the wire terminal strips connect the wires and once again be able to monitor the battery bank.

LESSON LEARNED:Even though the Xantrex manual says this unit is splash proof. It does not mention anything about the sun. Having the XBM display exposed to the sun (even though it was covered when not in use) is what lead to it's failing. I have reinstalled the XBM under the cockpit in a location that I can easy see it when I lift a cockpit hatch. That should offer more protection and prevent another failure of the display.

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