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]

Hi Gordonthree,

I've emailed them, and now have had a phone conversation. They did not understand the original email. The tech was intrigued when he finally understood what I was "going on about"

I do not have the BMK.

Solar was contributing 3.5 amps

There seems to be some sort of threshold with the voltage. It is hot today so I am running the roof air. Voltage is 117 and wattage is 14xx. Charging is happening at 49 amps in float mode.

I don't know the menus well at all.

GordonThree wrote:
Sounds like a programming issue, I'd recommend calling in to Magnum or whatever their new ownership calls them now.

Do you have the Magnum BMK as well, or just the charging amp-meter the remote provides? I'm wondering if the actual amperage into your batteries is different than the guesstimate shown on the remote.

Next question, how many amps were the solar panels contributing to the system?

Last question, in the ARC menus, what do you have your charging mode voltage thresholds set at? Perhaps with the solar coming in and not much load, the Magnum's computer decided the batteries don't need aggressive charging based on the voltage.

My ARC will not switch into Absorb until the load gets quite high, dropping the battery voltage, and Bulk comes in at an even lower voltage. I can look in my menus later today for you if you want to compare.

In one of the menus, there is an option to force the batteries to charge, equalizer mode or something? I've never done it on my bank, I don't think AGM need an equalizer charge - maybe Mex has some words of wisdom on that subject...

[MrWizard]

while thats true for weekends or part timing
get a big bank too low and you could spend a whole lot of time in bulk mode generator run time

with a 20% 12hr use (IF i did not charge during the day) i would be at 60% before bed tonight and 40% tomorrow morning
NOT the place i prefer to be
i can do that in a bad weather pinch, and the solar does mitigate the situation making it less strenuous than the straight math, and i could limit some of the power drain at night and make (2) with no charging
put that is winter time use, cool weather and no A/C, and less cooling strain on the fridge



different routines for different folks

[time2roll]

If I woke up to 12.5 volts I would not be running the generator.
Battery does not need to be perfectly 100% charged every day.

[MrWizard]

I think PT is saying the Magnum reduces charging at 122v input (some kind of thermal ? protection for the Magnum )
turning on the water heater (using genny power not inverter) reduces the yammy output line voltage to under 120v or less and the magnum then turns on and charges the batteries

he just recently got an auto transformer for Boosting low voltage shore power conditions
but it sounds like he needs to 'BUCK Down' the generator output, because of the finicky Magnum

it Is an unusual situation

Don
don't you have another converter you can plug in in this situation
39amps is no where near the max of the magnum
IIRC you do have something else that will supplement that 10 amps and get back to near 40amps charge

[GordonThree]

Sounds like a programming issue, I'd recommend calling in to Magnum or whatever their new ownership calls them now.

I've never had a problem charging like you describe, having to put a load on the system to make mine charge, but I've got the MS2812.

Only weird thing I notice on mine while charging, sometimes when it drops from Absorb to Float, the charging amps get stuck at exactly "15" while on the generator. I can have all my switchable dc loads off, and the BMK shows 0 amps going into the battery (per the shunt reading), yet the ARC remote shows 15 amps output on float charge.

If I turn the charger off, and on again, sometimes it'll drop to 0, or sometimes it'll stay stuck at 15.

Do you have the Magnum BMK as well, or just the charging amp-meter the remote provides? I'm wondering if the actual amperage into your batteries is different than the guesstimate shown on the remote.

Next question, how many amps were the solar panels contributing to the system?

Last question, in the ARC menus, what do you have your charging mode voltage thresholds set at? Perhaps with the solar coming in and not much load, the Magnum's computer decided the batteries don't need aggressive charging based on the voltage.

My ARC will not switch into Absorb until the load gets quite high, dropping the battery voltage, and Bulk comes in at an even lower voltage. I can look in my menus later today for you if you want to compare.

In one of the menus, there is an option to force the batteries to charge, equalizer mode or something? I've never done it on my bank, I don't think AGM need an equalizer charge - maybe Mex has some words of wisdom on that subject...