I’ve had a Victron 12/500w pure sine wave inverter for a few years now and it’s v good fir our occasional use. It runs with 2x85a exide gel batteries in a Westfalia James Cook. I’ve recently bought a Victron dongle for it from another Funster ( I also have another single fir the Victron solar controller). For the first time I can now see( and change if necessary)on the iPhone the settings fir the Inverter. It shows the low battery cut out at 9.7v and a low battery alarm at 10. something v. Those settings strike me as rather low? What do folk suggest as safe settings to protect the batteries when inverting? Thanks.
Victron Inverter settings
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Kannon Fodda
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At 10V it's commonly accepted that lead-acid batteries are totally flat. At 12V they are 50% and taking them regularly below that will shorten lifespan. GEL are a bit more tolerant in terms of capacity and being run down. If it's your occasional, non critical use, I'd set alarm at 12V, and cut off at around 11.8V so you can have plenty of juice left for other stuff. Note however that simply the current being drawn from the inverter may cause voltage to drop (which recovers when load is removed), so you voltages might need to be set lower just to find that happy balance.
The two cutoff settings are a compromise between damaging the battery by excessive discharge and nuisance tripping during normal operation. A 500W inverter takes over 40 amps on full power, which will cause an immediate drop in the voltage. This does not indicate a discharged battery, but is a reflection of the battery's internal resistance. Depending on the state of charge, the 'resting voltage' may be 12.0 to 12.8V, and the resistive voltage drop will take the voltage below those values. It's a trial and error process, and you are looking for the lowest cutout voltage that does not cause nuisance tripping in normal use.
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Lenny HB
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People keep quoting off load voltages as autorouter says they are not really relevant it's the onload voltage you are interested in.
A lot of Motorhome distribution systems have a low voltage cut off. With Elektroblocks it's 10.5v so I would set set the inverter cut off to 10.75v or above as you don't want the whole van electrics tripping out if the inverter pulls the voltage down to far. Set the alarm a bit above the cut out voltage.
A lot of Motorhome distribution systems have a low voltage cut off. With Elektroblocks it's 10.5v so I would set set the inverter cut off to 10.75v or above as you don't want the whole van electrics tripping out if the inverter pulls the voltage down to far. Set the alarm a bit above the cut out voltage.
Totally irrelevant for a battery under load.
Sorry, should be highest.
Lenny HB
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I think you were right first time.
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You can set alarm at 11,5v and shut down at 11v if settings allow. The voltage sag makes this setting to be quite low under load. That does not mean you over discharging. It all depends on rate of discharge. If you have small battery bank, the sag can be quite big, in this case 10,5v shut down with 11v alarm is ok. That if your discharge exceeds 0,2C; (20a discharge out of 100ah battery). If you have a big battery bank, and discharge rate is not to big, then 11,5v shut down with 12v alarm is better. A 0,1C max; That would be 10a and above discharge, out of a 100ah battery.
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If the cutoff voltage is too low, it allows unnecessarily low discharge. If it's too high, unnecessary nuisance tripping occurs. So it's the highest voltage, just below where tripping occurs.
gerry mcg
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I've got a 190Ah battery bank connected to my new victron Phoenix 12/500 inverter And the van has a Schaudt EBL 119 in it
What would the recommended alarm and low voltage cut off settings be?
11.5V and 11v respectively?
(i‘ve got a BMV700 battery monitor fitted)
What would the recommended alarm and low voltage cut off settings be?
11.5V and 11v respectively?
(i‘ve got a BMV700 battery monitor fitted)
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It's difficult to set something up like that because the exact voltage level depends on how much current is flowing.
Look at a NASA BM1 or 2 battery monitor the battery level is calculated by microprocessor and displayed as a percentage or bar graph. It also displays "time to discharged"
"time to charged"
Real Time Current, Voltage, starter battery voltage and amp hours meter.
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Lenny HB
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The EBL cut off voltage is 10.5v so as it is a bit higher should be OK.
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gerry mcg
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