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stuartbale avatar image
stuartbale asked

High Voltage Alarm

I have a Multiplus 3000 alongside a SRNE ML4860 solar controller on my boat. Im using a BMV-712 to monitor the setup. Frequently under prolonged heavy load, with a shoreline connected, the High Voltage Alarm (15v) will sound for about 30 seconds. The solar company recommended moving the negative from the shunt to the batteries. Is this a good idea?


MultiPlus Quattro Inverter ChargerBMV Battery Monitor
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boekel avatar image boekel ♦ commented ·

moving the negative from shunt to battery makes no sense - and BMV will not sense solar charger power also ;)

did you measure actual voltage at different points to check if readings are correct?
what values have you set in the solar charger and the Multiplus?
What is the temperature of the batteries? (lower temperature gives a higher charge voltage)

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stuartbale avatar image stuartbale boekel ♦ commented ·

Unfortunately I can’t reproduce this fault. It just happens sometimes and it only lasts for a few seconds so I don’t have time to get the engine board up to measure the voltage.

The inverter is on factory settings which is what the boat builder recommends.

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stuartbale avatar image stuartbale boekel ♦ commented ·

Solar charger set to default settings for SLD batteries.

Where do I find the temperature readings in the Multiplus?

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stuartbale avatar image stuartbale commented ·

Hi, thanks for your comment. Settings attached - the controller has default settings for battery type Mine are sealed lead and I’ve selected that type SLD in settings I’ve also tried altering the High Volt and Charge Limit Disconnect to 14.9v but it still reaches 15.2 - 15.5v



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boekel avatar image boekel ♦ stuartbale commented ·

these settings are fine, shouldn't go above 14,6V (equalise)

I asked for temperature, because at low temperature a lead acid battery needs a higher voltage. so is it possible that you have low temperatures?

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2 Answers
JohnC avatar image
JohnC answered ·

Hi Stuart. What you may be suffering from here are spikes generated from changing load on your batts, and the mppt taking a moment to compensate. And no, I'm not knocking your mppt, because I've a Victron and it does the same. My spikes aren't big enough to raise an alarm, but even with my per-minute graphing it occasionally picks it up. In my case usually caused by a 1200W ac pressure pump/accumulator stopping.

In effect, a 'false alarm'. By all means take note/check it until you're confident enough to ignore, or even raise the alarm setpoint.

With some kit these spikes may cause concern when a high V is registered for the day. I learnt long ago to ignore those once I understood what was happening. I don't know of a cure.

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stuartbale avatar image stuartbale commented ·

That seems to be the most likely answer. The load is also around 1200w but for a sustained period. As I said it’s only a matter of seconds so I think I’ll set the alarm a bit higher... thanks

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Paul B avatar image
Paul B answered ·

Have you set the SRNE ML4860 to the correct battery profile and what are the voltage settings of that profile,

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