Morningstar RD-1 put back to work

[ChrisOlson]

Well, when I came in for supper the master inverter was flashing an error for "Gen Failed to Start".  The reason is because it hasn't run for one month.  The inverter tried to start it and the battery in it was dead.  Generac recommends exercising the generator once every 7 days to keep the battery charged up because the electronics in the generator draw a small amount of power from the battery all the time.

Well, I don't want to exercise my generator once a week.  I got the inverter programmed to exercise it every 30 days.

There was two wires in the control cable from the GSM to the generator that weren't being used.  Those two wires would be for pre-heat on a diesel.  So I hooked those to the gen battery.  I didn't want to hook the other end to a battery in my battery bank because the bank gets down below 24 volts sometimes and this would discharge the gen battery and not be good for it.

So I re-installed the Morningstar RD-1 that I had just taken out when I installed my Classic 150 on the solar array and hooked it up to one of the batteries in the bank (12 volt).  I programmed it to monitor the voltage of that battery and when it's above 13.0 volts the RD-1 turns on a little ice cube relay that connects the gen battery to the big battery in the bank to keep the gen battery charged.

I suppose I could do the same thing with a little diode - if I had one laying around - but I don't.

I haven't found an end to dreaming up what one of them RD-1's can be used for yet.
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Chris

[tomw]

I suppose I could do the same thing with a little diode - if I had one laying around - but I don't.

I haven't found an end to dreaming up what one of them RD-1's can be used for yet.
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Chris

Chris;

I have a handful of diodes I will swap you for it!

[bj]

  Was about to make the same offer Chris, but then I remembered that picture Tom posted.
  So respectfully not making the offer.

[ChrisOlson]

Well, I want to try this for a few days and see if it works OK.  I got to thinking this morning that sometimes my bank, with the low-specific gravity Surrette's, goes up to 30.8 volts during absorb if the batteries are nice and cool.  That's not good for the genset battery either because it would take it up over 15 volts.

So I reprogrammed the RD-1 for a high and low limit of 14.4 and 12.8 so the genset battery is only connected to the bank battery if the voltage is within those limits.  The battery in that genset is just a little Yuasu unit about the size of a motorcycle battery.  Maybe 10 amp-hours or so.  I don't want to cook the little thing.
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Chris

[ghurd]

The battery in that genset is just a little Yuasu unit about the size of a motorcycle battery.  Maybe 10 amp-hours or so.  I don't want to cook the little thing.

VW solar panel?
The self regulated type are, well, self regulated.
The other type can be regulated for $5.

Or, more economically done, it could be maintained from the house battery bank.
Depending on the situation, $2(?), but it would not require a separate solar panel be purchased and installed.
G-

[ChrisOlson]

Or, more economically done, it could be maintained from the house battery bank.

That's pretty much what I'm doing with the RD-1.  I checked it today and the system spent a lot of time in bulk charging because of no sun and only light winds about 12-14 mph.  It held the little battery in the generator at too high of voltage too long for it, and it was gassing pretty good at 14+ volts after several hours.

So now I programmed a one hour timer in the RD-1 so it only charges the little battery for one hour a day off the RE system to keep it maintained, and I lowered the high voltage level to 13.5 volts.  So it starts charging when the house bank gets to 25.6 volts, stops charging when the house bank goes over 27.0 volts, and only charges for a max of one hour.

The poor little thing would've been boiled dry in about two weeks the way I had it set.
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Chris

[Volvo farmer]

That sounds like a pretty complicated way to keep a generator battery charged. I put a 5 watt amorphous panel on a teeny 3.2 Ahr  SLA battery that powers the solar tracker for my well pump. The amorphous panel tracks with the main array and we get over 260 sunny days a year here.  It's been out there a long time, I'm sure over a year without me fooling with it. I have no charge controller on it and I thought I'd boil the battery dry in three months but it keeps on going.

Maybe I'm just lucky that the power to run the linear actuator approximates the power of the solar panel every day. Maybe a 5W panel would boil a generator battery dry with no daily loads for a month. Still it seems so much easier to use a small solar panel for this type of task than fiddling with settings on a logic module.

[tomw]

Chris;

Speaking of VW Solar Panels..

I might work a swap for a VW solar panel I have for that RD and some coin? Was needed for the Bug when it sat  winters unused.  We got rid of that albatross when we got the Fiesta. A convertible was nice occasionally but 38+ MPG is nice every day!

Anyway I have one that is not being used.

Tom

[ChrisOlson]

Well, being that I got it wired into the GSM I'd like to try it for a month and see how it works.



I wired up two channels on the RD-1 because I think I might be able to use it in the winter too.  I got the second channel programmed as an input channel and it's wired to RY11 in the Generator Start Module.  If the gen fails to start after three tries in really cold weather, it's got three tries left before the inverter locks the gen out with a Fail To Start error.  I can have the inverter activate RY11 (which is an alarm channel) after try #3.  When the RD-1 senses the alarm input on channel 2 it will activate the relay, hooking the genset battery to the big bank for extra "boost" for cold weather starting.

LOL!  Like I said, I really haven't come to an end of dreaming up what one of these RD-1's can be used for.  But now that I got it back in use I'd like to try all this stuff.
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Chris

[ChrisOlson]

Well, as it turns out this didn't work all that great in the end.  The RD-1 basically draws a few milliamps of idle power and that's negligible.  But what happens is that when it engages the relay the 1/4 amp draw from the relay coil, plus the draw from the genset battery, causes the voltage to run low by up to a 1/2 volt on the battery that it's hooked to on the bank.  This causes the other battery that's in series to run high on voltage by up to a half volt and it gets the living snot boiled out of it while the "maintainer battery" doesn't.

A little solar panel that puts out a couple watts or so, just to cover the draw from the electronics in the gen, will work better.  It's what I should have done in the first place.  But I didn't have one.  TomW had one, and he needs an RD-1.  So we got a "deal" worked out that will work better for both of us   

This was a nice experiment.  But it's really hard to put any sort of a load on part of a series battery bank and keep the bank perfectly balanced.  Keeping those batteries perfectly balanced is pretty much key to long life and proper charging.  So in the end I had to scrap this idea and go to "plan B".
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Chris

[ghurd]

For Plan A, the little battery's charging current should have been pulled from the house banks series strings, and not a single battery in the string.
G-

[ChrisOlson]

For Plan A, the little battery's charging current should have been pulled from the house banks series strings, and not a single battery in the string.

Well, the problem is that I got Rolls-Surrette T12-250's and those are six cell 12 volt batteries.  My system is 24 volt and the genset battery is 12 volt.  There's no place I could hook to in the bank that would not cause an imbalance.

I could have had the RD-1 turn on a little 120 volt battery maintainer that runs off the inverters for a couple hours a day.  That would work fine.  But at that point it was like, well .......  one of them little 3 or 4 watt solar panels makes more sense   

In the winter I don't need the genset battery maintainer.  But in the summer we get lots of solar and our loads are lower so the genset turns into yard art and it's not used.  Things in the winter that take a lot of power, such as my wife's electric clothes dryer that will cause the gen to start in Peak Power Management Mode, don't even get used because the clothesline works in the summer without freezing the clothes into solid ice.

I put my digital ammeter on the genset to see what it draws.  The idle power consumption of the electronics in it is 40 milliamps, which is about 1 amp-hour a day.  In two weeks, if it doesn't run to recharge the battery, the battery is low enough that it won't start.  That little VW solar panel, if it can replace 1 amp-hour per day, on average, will work perfect.
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Chris

[ghurd]

For Plan A, the little battery's charging current should have been pulled from the house banks series strings, and not a single battery in the string.

Well, the problem is that I got Rolls-Surrette T12-250's and those are six cell 12 volt batteries.  My system is 24 volt and the genset battery is 12 volt.  There's no place I could hook to in the bank that would not cause an imbalance.

That little VW solar panel, if it can replace 1 amp-hour per day, on average, will work perfect.

I understood what you thought the main problem was.
Solution, quickie style?


The VW PV will work great, has no conversion losses, and it will not have a gazzillion feet of wire to run.
And if I am not mistaken, that particular VW PV has a built in controller.
G-

[ChrisOlson]

Oh, OK.  I don't have the electronics knowledge to make something like.  Or I could make it now that I've seen it, but I don't know how to go about designing something like that.

The little solar panel came from Tom today in the Universal Package Smasher truck.  I wired in a cig socket to the genset battery and mounted the little solar panel on the top of the gen housing.  I ran the cord thru the access panel and plugged it in (it has a cigarette lighter plug on the panel).

The battery was at 12.44 volts when I plugged it in.  It took about 30 minutes and it had already come up to 12.92 but it wouldn't go over that.  I checked the open voltage of the little panel and, cripes, it was 18 volts.

After the sun went down a few hours ago, now the battery is at 12.52 volts.  So it didn't put a lot of juice into it and it's not fully charged.  But it was only on there for maybe 4 hours today.

I think it's going to work fine.
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Chris

[ghurd]

How's it doing now?
I expect it'll take a couple/few days to get the battery up to a decent voltage, then it will keep it there just fine.

If the panel will be out side, probably want to open the frame, add some non-acid silicone (Dap 3.0?) to the wires on the back so keep them from corroding, and seal the frame a bit to keep water from collecting where it can freeze in the frame.
They were not designed to be outside.
G-