Steca MPPT 2010 and sealed batteries

[BruceinSanity]

I've just changed my batteries from Trojans to Albion maintenance free. Conditions in the engine bay under the back deck meant that the Trojans didn't survive long enough to justify the extra cost and I've joined the treat-them-as-consumables party.

 

The only problem I've got now is that with all this bright sunny weather, the Steca 2010 solar controller is getting up to 14.6V at times when the batteries are supposed to be on 14.4V for absorption. Tail current is 1.5A. There's no sign of gassing off through the PRVs on the batteries and I guessing that that low current means not a lot is going on. The Albions have calcium doped plates.

 

The 2010 can only be adjusted by laying out another £107 for a control unit I'm only likely to use once. Do I need to do anything apart from hope for cloudy weather?

[ditchcrawler]

Go cover the solar cells with lace blinds, that should sort it.

[nicknorman]

I'd say 14.6v for calciums is not too high.

 

Out of interest how long did your Trojans last and why/how did they die?

[BruceinSanity]

I'd say 14.6v for calciums is not too high.

Out of interest how long did your Trojans last and why/how did they die?

Thanks for that, it's what I hoped. The Trojans did four years, but have been pretty dodgy for the last six months, gassing off a lot at absorption voltages and down to about 30% capacity. I was disappointed with their performance from the start and did wonder if I had a duff batch. They were nursed by me, monthly top up, never discharged below 70%.

 

The problem was what I raised in a thread last autumn. After a very long run (9 hours) in hot conditions, the tail current had risen to nearly 20 amps and investigation showed that the blocks were at about 45C. I stuck some digital temp strips on both the batteries and the frame they stood on and showed that even in more normal conditions things were getting over 30C. SA is a typical modern trad with a Beta 43 in an engine box and everything gets a bit warm down there.

 

So I concluded that paying out for deep discharge batteries and a watering system to overcome access problems was a waste of time and dosh and that as long as I get a couple of years out of these, which were £75 apiece, I'll be better off.

 

I should explain that SA was the first Braidbar to have a Hurricane and Peter Mason put it where he'd normally put the battery bank, shoving the latter aft under the electric cupboard and closer to the exhaust. Fitting a Hurricane was a mistake in so many ways!

[Chewbacka]

........................................I stuck some digital temp strips on both the batteries and the frame they stood on and showed that even in more normal conditions things were getting over 30C. SA is a typical modern trad with a Beta 43 in an engine box and everything gets a bit warm down there................................

If you are bothered about the temperature, you could fit a bilge blower in the engine hole to extract hot air, but they can be a bit noisy without some sound absorbing material around them and using noise absorbent mounts.

[cuthound]

As batteries are chemical devices, raised temperatures can kill them quite quickly.

 

In the telecoms world, VRSLA'S lasted 10 years at an average temperature of 20°C, but this halved when it was raised to 35°C.

 

What you describe sounds like plates shorting on one or more cells.

[rupertbear]

Fitting a Hurricane was a mistake in so many ways!

 

That's interesting, I can't recall much criticism of the Hurricane. Would you like to tell more?

[BruceinSanity]

As batteries are chemical devices, raised temperatures can kill them quite quickly.

In the telecoms world, VRSLA'S lasted 10 years at an average temperature of 20°C, but this halved when it was raised to 35°C.

What you describe sounds like plates shorting on one or more cells.

Quite agree with both points. I reckon that material shed from the plates had shorted out cells in two blocks completely and was reducing capacity in the other two. Other premonitory signs of failure were the tail current not falling below 7 amps even after six hours at absorption and the Mastervolt failing to go to float until it timed out for that reason.

 

Hence my decision to see how long I can get out of a set of el cheapo batteries.

[BruceinSanity]

That's interesting, I can't recall much criticism of the Hurricane. Would you like to tell more?

Sure. The Hurricane is an excellent design concept and great for liveaboard purposes as long as it is working. The problem is build quality, especially of the compressor which pressurises the fuel so that it aerosols out of the jet. Having had one fail at 4000 hours and the replacement give up after only 1500, I wasn't inclined to lay out another £500+ for a third one. Other factors in this decision were that we are no longer true liveaboards, staying in our lodge in Mercia over the winter, and getting fed up with not being sure if the boiler is going to consent to fire up in the morning.

 

We've replaced it with a Webasto which will be fine for our current boating style, but it means that things like the location of the battery bank are a legacy of the original decision. You probably know that the Hurricane is a much bigger beast than the Webasto. I don't understand why the compressor should be such a problem; after all, it's the same tech as every turbo diesel and I'm not aware of loads of them suffering compressor failure.

[cereal tiller]

Sure. The Hurricane is an excellent design concept and great for liveaboard purposes as long as it is working. The problem is build quality, especially of the compressor which pressurises the fuel so that it aerosols out of the jet. Having had one fail at 4000 hours and the replacement give up after only 1500, I wasn't inclined to lay out another £500+ for a third one. Other factors in this decision were that we are no longer true liveaboards, staying in our lodge in Mercia over the winter, and getting fed up with not being sure if the boiler is going to consent to fire up in the morning.

 

We've replaced it with a Webasto which will be fine for our current boating style, but it means that things like the location of the battery bank are a legacy of the original decision. You probably know that the Hurricane is a much bigger beast than the Webasto. I don't understand why the compressor should be such a problem; after all, it's the same tech as every turbo diesel and I'm not aware of loads of them suffering compressor failure.

That Compressor on the Hurricane is weak component and very expensive to replace.

 

Fitted one last year and I recall the cost was close to £300

 

CT

[BruceinSanity]

Now here's a thing. Went onto the boat this pm to do some stuff preparatory to us moving out of the lodge tomorrow (tenant arriving on Friday for a week) and the voltage is 15V. Ulp.

 

We've covered the panel for the moment. CO alarm indicates very small amount of H2 immediately over the battery box so hopefully not too much damage. Please...

 

Looks like the Steca has gone t*ts up.

 

This has all just started happening since I changed the bank on Saturday, and I'll check all connections again tomorrow after we're back on board, but I can't think of a way a bad connection would lead to OVERvoltage at the bank. The reading is the same on the SG and a NASA Clipper, so not likely to be a faulty gauge.

 

What a b*gger, looks like I might have to lay out for a new controller.

 

All suggestions welcome, of course, but I'm well on the way down a bottle of Shiraz Mataro now, so not likely to be very responsive for a bit .

[ditchcrawler]

Now here's a thing. Went onto the boat this pm to do some stuff preparatory to us moving out of the lodge tomorrow (tenant arriving on Friday for a week) and the voltage is 15V. Ulp.

 

We've covered the panel for the moment. CO alarm indicates very small amount of H2 immediately over the battery box so hopefully not too much damage. Please...

 

Looks like the Steca has gone t*ts up.

 

This has all just started happening since I changed the bank on Saturday, and I'll check all connections again tomorrow after we're back on board, but I can't think of a way a bad connection would lead to OVERvoltage at the bank. The reading is the same on the SG and a NASA Clipper, so not likely to be a faulty gauge.

 

What a b*gger, looks like I might have to lay out for a new controller.

 

All suggestions welcome, of course, but I'm well on the way down a bottle of Shiraz Mataro now, so not likely to be very responsive for a bit .

Did you disconnect the panels before removing the batteries and not re connect them until the batteries were connected. That was the problem on a posting the other week.

[BruceinSanity]

Did you disconnect the panels before removing the batteries and not re connect them until the batteries were connected. That was the problem on a posting the other week.

Did more than that, covered the panels until everything else was done. Furthermore, the controller has had the rapid flashing green LED that means "Batteries full, current restriction applied" so it was still working to 12V.

 

Anyway, I thought it turned out the other case wasn't a mis-set controller, it was just determined to do an inappropriate equalisation charge? Reconnecting everything in the right order didn't help.

[Cas446]

Try reducing your boost/absorption return/reconnect voltage. It could be that your battery voltage drops sufficiently overnight that your controller starts another 2 hour absorption every morning which causes the battery voltage to rise too much. If you can't change the setting then disconnect some panels and just leave one connected.

[BruceinSanity]

Try reducing your boost/absorption return/reconnect voltage. It could be that your battery voltage drops sufficiently overnight that your controller starts another 2 hour absorption every morning which causes the battery voltage to rise too much. If you can't change the setting then disconnect some panels and just leave one connected.

It's not adjustable unless I buy the extra bit of kit. It has a so-called equalisation setting that's supposed to run every month, but it's only 14.7V, way below the 15V it did the other day. Absorption on the Steca should be 14.4V as usual for wet lead acids.

 

There's a bit more to the story today. After swapping sealed for Trojans, I needed to change the dip switches on the MasterVolt because of the changed battery type. I didn't manage to do that until today – access problem required daughter's slimmer fingers and left hand dexterity – and when I did, lo and behold, the dips had never been changed when the Trojans were put in and were still in default battery mode. Yet the Trojans had been charging at 14.6V with both the Steca and the MV feeding them. Today the MV alone did a perfectly normal bulk/absorption/float charge when I fired it up. It's currently holding the bank at 13.2V.

 

So I suspect that the Steca has been running overvoltage for some time, years perhaps. I've currently got the panel covered and the Steca disconnected. Next decent day for sun is likely to be Sunday, when I plan to turn the MV off and reconnect the Steca, batteries first, naturally.

 

We shall see what happens...