an unusual charging problem

[pianotuna]

Hi all,

I'm generator charging from need for the first time in my life. It is not hot enough to run the roof air.

Here is a bit about the system.

Magnum 3000 Hybrid 12 volt to 120 volt with ARC remote

Yamaha 3000 sIEB inverter generator

4 139 amp-hour surplus acid telecom 12 volt batteries totaling 556 amp-hours. These are a bit unusual as their specific gravity is 1.3 rather than the more normal 1.275. They have a slightly higher voltage.

256 watts of solar into a Blue Sky 3024 di controller.

voltage monitored with a kill-a-wall unit

Wattage monitored by an Efergy Elite classic watt meter.

Charging rate monitored by the Magnum remote.


Conditions:

Batteries were not fully charged yesterday and were used overnight. Remote display said 12.5 volts.

I started the generator leaving it at maximum output.


I made the following observations:

Remote went immediately to float charging at 10 amps

Load was the fridge at 311 watts (2.5 amps)

Voltage was 122.

I turned off the fridge. No change in charging rate or voltage

I increased the load on the system by turning on the water heater 1300 watts (11 amps) voltage 118

Charging rate increased to 39 amps.

I turned off the water heater and charging amps slowly dropped back down to 10.

The "trigger" point for higher amp charging appears to be about 1300 watts. Doing so may double the fuel consumption rate. I'd prefer to avoid this.

[pianotuna]

Trust MrWizard to hit the nail on the head.

I've fine tuned the voltage drop needed. If I can keep at 120 then it behaves well, and the Yamaha can run at the slowest possible speed.

I wonder what the folks with Honda's where the voltage is 126 to 128 would do to drag the voltage down.

[MrWizard]

Yes there is.. Fuel consumption
Turning on extra loads, to get the magnum happy, so it will charge properly

[time2roll]

pianotuna wrote:
I did not wake up soon enough so solar has it at 12.6

Not sure if there is any real effect from the problem.

[pianotuna]

Hi Mr Wizard,

You may be right about the wave form being "too tall".

I did get it to charge in bulk yesterday with the roof air running. Charging rate was 102 amps in Absorb at 12.7 volts. I got in over an hour or more.

No word back from Magnum. They want me to test on 30 amp shore power. Of course it will work fine on that.

[BFL13]

If no scope, just tap it with your tuning fork. 🙂

[MrWizard]

Don
Have any friends with an oscilloscope
You need to observe the wave form before connecting the magnum
With magnum misbehaving
With added load

[pianotuna]

Hi smk,

I did not wake up soon enough so solar has it at 12.6

[time2roll]

What was the battery voltage this morning?

[pianotuna]

It does not seem to matter what the load type is. If I can get the voltage down to 118 the Magnum charges well. The air conditioner does the trick. So does the induction cooker if I run it high enough.

[BFL13]

That sounds like the trick to add a non-inductive load to the inverter when trying to run a purely inductive load.

My Vector 2000 MAXX SST (MSW)inverter, which runs motors, and microwaves, (and converters when I forget to turn that off) has in its trouble shooting guide, "Motorized power tool does not operate or correct speed" Cause- "Purely inductive load" Suggested Remedy- "Make the load not purely inductive. Operate an incandescent lamp at the same time as the motor."

[MrWizard]

BFL13 wrote:
I don't understand PT's set-up at all. but perhaps he can actually get his batteries charged without all this power sharing stuff the Magnum does if he just splits his battery bank when doing a recharge, and does half at a time where the charger can do its full rated amps?

I doubt it is a generator limitation. I can charge at 155 amps with my Honda 3000 using a PF corrected 100 and a non-PF corrected 55 both set at 14.8v.

PT is doing something weird! 🙂

His magnum inverter charger is doing something weird

And I think it is in the Yamaha output wave form
The magnum thinks there is something wrong with it and is limiting power
Maybe the peaks are too high?
When he adds load to the power from the generator the wave form changes (lower peaks?) And the magnum kicks on and charges the batteries
It would be handy if he could test this with some other generator
Maybe then a/c on low instead of the WH , then switch to fan mode? After the magnum kicks into charge
Find out how much load is needed to condition the voltage so the magnum accepts it

[pianotuna]

Hi BFL13.

Well, splitting is something new to try.

I'm not doing *any* power sharing. I'm simply using the Magnum as a glorified battery charger.

I don't understand *why* when I increase the load on the generator that charging amperage RISES. It is certainly counter intuitive. I expect that splitting will made the situation worse, not better.

BTW doing weird stuff--well thank you--that's compliment coming from the guy who sometimes uses 4 chargers at one swoop.

BFL13 wrote:
I don't understand PT's set-up at all. but perhaps he can actually get his batteries charged without all this power sharing stuff the Magnum does if he just splits his battery bank when doing a recharge, and does half at a time where the charger can do its full rated amps?

I doubt it is a generator limitation. I can charge at 155 amps with my Honda 3000 using a PF corrected 100 and a non-PF corrected 55 both set at 14.8v.

PT is doing something weird! 🙂

[pianotuna]

Hi BFL13,

Yes, (assuming zero losses) the Sola Basic looks like this:

IN
100 volts @ 12 amps = 1200 watts

OUT
120 volts @ 10 amps = 1200 watts.

That is simplified of course, because the autoformer does "cost" 4% to operate. So the "in" side would be about 1248 watts, not 1200. Since you prefer amps that would be 12.48 amps rather than 12.

BFL13 wrote:
"which could be more useful than expect it to boost power."

I would assume that it cannot boost Power since you can't get more out than in, but it could perhaps boost voltage while reducing amps for the same power?

[pianotuna]

Hi happy,

This is off topic.

The Sola Basic autoformer does raise voltage on the output side.

Since you refuse to open the link (and perhaps learn something) here are the figures for the first stage of boost.

Voltage with no load in the RV

Shore power input 114; output from Sola Basic inside RV 114

Voltage with air conditioner running

Shore power input 107; output from Sola Basic inside RV 117

All measurements were taking with a Kill-a-Watt meter.

Low voltage in Campgrounds is endemic when ever air conditioning is needed. Why? Because your beloved NEC allows 9 50 amp pedestals to be fed by one 200 amp circuit. It is even worse with 30 amp where 13 are allows on a 200 amp circuit. Further, over all, the campground only has to have 41% of the total capacity.

Now, do you have anything to contribute that is on topic?

happycamper002 wrote:

pianotuna wrote:

Nec may forbid "hard wired" installation of devices, but since my autoformer unit is a plug in device it is not forbidden and is perfectly legal. There are many thousands of these in use in Mexico.

Mexico is not US. Besides, you can google some manufacturers who jumped into this bandwagon only to discontinue this product or went belly up because they cannot fool all the people. No one will stop you from using it or simply using it as foot rest which could be more useful than expect it to boost power.

There is no doubt this can be useful in Mexico because some rural areas there are feed by 240Vac. Having a center tap will enable you to use 120Vac appliances sold for US consumer.
I refuse to open the link you provided because I don't want to be suckered just like the rest.

[GordonThree]

BFL13 wrote:


PT is doing something weird! 🙂

That's what makes the challenge fun!