Your last generator Maintenance Run

[3930dave]

A question for those who use a battery maintainer on their generator:

Is it safe to leave a maintainer connected to both the battery and A/C power while the generator is running? With vehicle batteries, either the A/C or DC side must be disconnected when the vehicle is moved. Not so with a stationary generator.

I had a BatteryMinder, which I used on dozens of batteries in boats, trailers and vehicles for over 30 years. I hooked it up the the battery on my generator and it worked fine leaving it connected to AC & DC while doing short maintenance runs. We had a 6+ hour outage a couple of days ago though and the BatteryMinder failed. It overheated and the case is noticeably swollen.

I'm planning on replacing it with a Noco Genius 10, which states in the manual that it is ok to leave both AC and DC connected.

Has anyone else had this problem? There is nothing in the BatteryMinder manual that says to disconnect it from a running engine. The unit was over 30 years old, maybe it was just its time.

Might have just been age.....

Modern chargers often prefer (crazy guy here, reads Owners Manuals...) to have DC connected before AC... guessing they use the DC to have the micro-controller Up, before AC arrives, but that doesn't sound like your sequence, and much of the older stuff never specified sequencing.

On my new chargers (like above), I usually add a label "DC First, DC Last", to remind myself.

Rgds, D.

 

[Fallon]

Might have just been age.....

Modern chargers often prefer (crazy guy here, reads Owners Manuals...) to have DC connected before AC... guessing they use the DC to have the micro-controller Up, before AC arrives, but that doesn't sound like your sequence, and much of the older stuff never specified sequencing.

On my new chargers (like above), I usually add a label "DC First, DC Last", to remind myself.

Rgds, D.

More likely they are relying on the battery to buffer the PWM output from the controller. You can run a car without a battery, at least older ones. But that is really hard on the voltage regulator & diodes.

If you have 2 controllers outputting exactly 12v both would push equal amperage to the battery. If one cut off at 12v & one at 12.1v, the 12v one wouldn't contribute anything as it would be below the cutoff voltage & the 12.1v one would drive things. In reality due to voltage loses in wiring & stuff, both would contribute some amperage.

 

[LittleBill21]

My toy hauler has 400watts of solar connected all the time. It stays live even when towing or plugged into shore power. Multiple charge controllers or converters output 12v nominal with each other just fine.

yep same here.

 

[LittleBill21]

Onan perhaps ?

I seem to recall seeing Elevation stickers on some RV Onans, once upon a time....

Rgds, D.

yes the onan 4k have the adjustment, i have the same generator.

 

[LittleBill21]

the thing that blew my mind after years of playing with this stuff, was when the dc negative, ac ground, and ac neutral for the generator were all attached to the same bolt, for reason i thought that would screw with things, but its been like that for 25 years.

 

[aba4430]

Back-up Eaton branded Generac 20KW generator ran for ~6 hours last night/ early morning due to power outage; hence inherent exercise. However, about 3 hours into the run, we got a note from our Utility company that power had been restored. The generator kept on running and the transfer switch did not switch to utility power.

The Utility company is excellent and when I reported that we still had an outage they send a crew truck to investigate our new smart meter that had been installed ~3 weeks ago. No issues were noted. They did indicate that there could be an issue with the transfer switch instead and to seek professional help from an electrical contractor.

I started browsing the web for automatic transfer switch issues. I pulled the transfer switch panel cover off and found a wire with a spade terminal totally disconnected from the utility coil. We have had 4 or 5 outages since we moved into our present home a couple of years ago and there have been no issues. The connector must have been barely secured to the coil terminal and had come loose. I shut the utility power switch off and reconnected the wire to the spade terminal securely. Turned the switch back on and after a few seconds, the solenoid activated and transferred power to Utility. In less than a minute therafter, the generator shut down and all was well. This was @0330 this morning.

I am learning new stuff everyday.

 

[grsthegreat]

Amazing. Those wires do have a tendency to come loose, but usually fairly soon after installation. I check these wires everytime i do a generator service call. I hope you crimped that connection a little tighter before reinstalling it.

 

[orezok]

I installed a 8kW Generac 10 or so years ago and it served us well for all that time. But 8kW has it’s limits as it would not power the AC, oven, shop or other large draws.

We are getting older and decided to up grade to a 22kW which will power everything.

Well, in the 8 months since I installed it we have a total of 3 hours of actual run time including start up, testing, exercise and a couple of short outages.

Nothing guaranteed no more outages than spending $$$ on a new generator!

 

[grsthegreat]

I installed a 8kW Generac 10 or so years ago and it served us well for all that time. But 8kW has it’s limits as it would not power the AC, oven, shop or other large draws.

We are getting older and decided to up grade to a 22kW which will power everything.

Well, in the 8 months since I installed it we have a total of 3 hours of actual run time including start up, testing, exercise and a couple of short outages.

Nothing guaranteed no more outages than spending $$$ on a new generator!

You got that right. But i like knowing its there. Not much different than my neighbor that bought a nice new pontoon boat several years back…has never been out of the shop. But it looks nice sitting there. He thinks, some day ill be glad ihave this boat.

 

[bdhsfz6]

I installed a 8kW Generac 10 or so years ago and it served us well for all that time. But 8kW has it’s limits as it would not power the AC, oven, shop or other large draws.

We are getting older and decided to up grade to a 22kW which will power everything.

Well, in the 8 months since I installed it we have a total of 3 hours of actual run time including start up, testing, exercise and a couple of short outages.

Nothing guaranteed no more outages than spending $$$ on a new generator!

It's called "Insurance".