MPPT Failure

[rajjes]

So last year I upgraded to 2 X 100W solar panels feeding a domestic bank of 400AH through an MPPT controller (of the cheap variety). All went well and I could enjoy cold bears while keeping the batteries charged!

Yesterday I went out for a good day sail and after switching off everything on leaving the boat I checked out the battery monitor and found it charging 6 amps at 16.5V!

I immediately checked the mppt and it was dead with no indicator lights whatsoever when usually during normal operations it has some 3 indicators.

I have temporarily removed the solar fuse to disconnect supply but am very concerned that the mppt was not a fail-safe design.

I dread to think what could have happened if I did not notice the charging rate and left the batteries cooking for possibly a few weeks!

So some questions:
Which MPPT controller would you recommend within a reasonable budget?
How can I be sure that something similar will not happen again with the new controller?

 

[Monique]

The BEST MPPT according to me.... Victron.

You define what a reasonable budget is for you... if you have to replace your batteries after they've been cooked by a "budget" MPPT.

GL

 

[Trundlebug]

+1 for Victron.

Before I bought mine I did extensive research, and I mean extensive.

Although there are plenty of "claimed" MPPT controllers out there for very low prices off ebay, they're all names you've never heard of, with a look and price that tell you where they were made and that they're not the real thing.
I came to the conclusion that the best value REAL MPPT controller was Victron.

 

[ip485]

Outback controllers are excellent and had absolutely no issues at all.

 

[nigelmercier]

Probably the Victron 75/15

 

[gregcope]

The BEST MPPT according to me.... Victron.

+1

 

[gregcope]

Probably the Victron 75/15

I have one of these. Can do upto 200W of solar, so will be at the top end of its range, and you will not be able to expand.

Suggest you consider the model up.

It is a good price mind.

 

[ChrisRayner]

I could enjoy cold bears while keeping the batteries charged!

I confess, I have a minor disability. I read what people spell, not what they mean. These bears, were they polar?

 

[rajjes]

Thanks to all, I just ordered the Victron 75/15.

 

[William_H]

Just as a matter of interest it is likely the cheap MPPT controller had a buck converter. This essentially has a transistor switched at high speed between the solar input and the battery +ve via an inductor diode arrangement to recover the additional power. Anyway a simple failure of the switching transistor to an internal short (typical failure mode) would give the symptoms you mention. ie solar direct to battery no regulation. good luck olewill