inverter bulk charge voltage low

[Russell Clifton]

I have a Magnum ME2012 2000 watt inverter. When beginning the bulk charge mode it should charge at 14.6 volts. This voltage is automatically set when you are charging conventional wet cell batteries. This morning it will not go over 13.4 volts. ( this just happens to be the correct voltage for float charging). I am running on my generator this morning. Is there a way to reset the inverter/remote and reboot it? Thanks.

 

[DavidM]

Don't assume that your charger is at fault. When batteries are well discharged or have gone bad, even a 100 amp charger can't bring the voltage up significantly. It is particularly noticeable with a large battery bank and a relatively small charger. The charger just doesn't have enough output to push the voltage up significantly until the charge has built up some.

Your 2000 watt inverter probably has a 75-100 amp charger which is pretty big, but how big is the battery bank they are charging. And what is the resting voltage before you start charging?

So leave it charging for a while and see if it doesn't rise. If it doesn't then check your batteries for failures.

David

 

[Ka_sea_ta]

Bulk Charge is constant current.... if the batteries are discharged you wont see a higher voltage until they are about 70 to 80 percent charged.

 

[cafesport]

What was the voltage before you started charging? Also did you install the temp sensor? Did you mess with any of the settings... change battery type perhaps?

 

[kchace]

Don't assume that your charger is at fault. When batteries are well discharged or have gone bad, even a 100 amp charger can't bring the voltage up significantly. It is particularly noticeable with a large battery bank and a relatively small charger. The charger just doesn't have enough output to push the voltage up significantly until the charge has built up some.

Your 2000 watt inverter probably has a 75-100 amp charger which is pretty big, but how big is the battery bank they are charging. And what is the resting voltage before you start charging?

So leave it charging for a while and see if it doesn't rise. If it doesn't then check your batteries for failures.

David

This!

 

[sunchaser]

Russ
As asked already, is this a new thing or ??? My Magnum responds similarly at times. Do you have a BMK? If so what is SOC, instantaneous amps delivered and battery voltage with charger off?

Also you mentioned genset running. I take it you are anchored as opposed to at the dock. If so, what is genset voltage reading? My Magnum can have a different charge profile when anchored with genset running vs at the dock.

 

[Russell Clifton]

Charging four 8D. Got below 12 volts last night. Lowest it has ever been. I found how to reset and did that. Voltage has come up a little in the past two hours. Maybe just jumped the gun. Headed back to the dock now. Will see how it does on shore power. Thanks guys..

 

[High Wire]

Charging four 8D. Got below 12 volts last night. Lowest it has ever been. I found how to reset and did that. Voltage has come up a little in the past two hours. Maybe just jumped the gun. Headed back to the dock now. Will see how it does on shore power. Thanks guys..

Do you have the Remote Panel?
It may have gone thru Bulk, Absorb, and reached Float. There is a minimum time in the Absorb mode before switching to Float. This time is programmed and is adjustable (I think 90 mins is default setting). Was it in charger mode long enough to reach Float?

 

[cafesport]

So a voltage below 12v I’m guessing is around the 50% zone. It’s gonna take an hour or so for bulk charging to bring the batt voltage up to the cut off threshold to start into the absorption phase. Probably stay there for a few hours as well. Are these la or agm. You can use the custom battery setting to tweak the charger to run whatever voltage and time parameters you want.

 

[Mischief Managed]

Does not matter what the output voltage is supposed to be, if the charge current is maxed out, the charger is doing the best that it can do.

 

[STB]

Try shutting down the charger, letting the batteries cool, checking the water level, charging for a bit if any cell was seriously low, checking the battery fluid with a refractometer or hydrometer if you happen to have one, applying a light load for a few minutes, and then checking voltage.

I put the chances at 75% that the battery is bad or way low charge.

 

[bayview]

Check the batts with a hydrometer.

 

[JDCAVE]

One other point. Make sure the charge function on the remote panel is set to “Charge” and the light is on before switching to shore/genny charging. Otherwise the unit may go directly to “Float” before first going through the “Bulk” and “Absorb” phases.

Jim

 

[Mischief Managed]

Just to be clear, what you are experiencing is normal when the batteries are very discharged. There is likely nothing wrong with the inverter/charger, the batteries are simply dragging the voltage low while they charge. The charger is amperage-limited so when the charger amperage maxes out and the batteries still want more, the only thing that can happen is the voltage will decrease. If the voltage could be held higher, the amperage would increase and the inverter does not have the capacity to provide any more current.