question

choctaw avatar image

Battery Protect 12V 220A does not cut of the power. What's wrong?

My newly installed SBP 220Amp model does not switch off the power once the low voltage has been reached.
On the BT-App, there is a message after 12 seconds that there is a low voltage alarm, but the SBP does not switch off.


When I use the switch in the App, the power is cut-off.

What wrong? Only a visible alarm is not enough to protect my batteries.


MPPT - Solar Charge ControllerLithium BatteryBattery Protect
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5 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

After 12sec you get an alarm but the power gets cut after 90sec. -> manual

What kind of inverter do you use?

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Justin Cook - Bay Marine Supply USA avatar image
Justin Cook - Bay Marine Supply USA answered ·

@Choctaw, generally speaking this is a sign that the Smart BatteryProtect has been irrecoverably damaged due to a forbidden connection.

How do you have the device connected?

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choctaw avatar image
choctaw answered ·

Hi, thanks for your reply. The SBP is connected as per manual. Between the battery and the inverter. The only task is to cut of the inverter when battery voltage drops below the setting.

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Justin Cook - Bay Marine Supply USA avatar image
Justin Cook - Bay Marine Supply USA answered ·

@Choctaw, please review the manual here and in particular note item 4 which specifically instructs not to do that. Using a BP or Smart BP to directly disconnect the main DC line of an inverter is forbidden because it will -sooner or later- cause damage to the BP, which is what you're now seeing.

Unfortunately this damage is not recoverable; your only option at this time is to contact the authorized dealer or distributor from whom you purchased the device and see if they will work with you to get a new unit; the damage won't be covered by the warranty, but the dealer may make you a deal on a new one - that's between you and your dealer.

Regardless, however, if/when you get your new unit, you must not connect it in this way again or it will fail. Scroll down to the second page of the manual to see acceptable ways to accomplish a low-voltage shutdown of an inverter, although whether this is simple or requires the use of an external relay or other device depends entirely upon your inverter manufacturer/design.

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choctaw avatar image
choctaw answered ·

Thank you all for your wisdom. I have been too impatient and didn't wait for 90 seconds. I never noticed the 90seconds in the specs.

It is still working fine, but, as Justin is mentioning, will it stay alive with my Inverter?

It's a Whisper Power inverter 2000W model. Not the cheapest, but maybe not the most sophisticated either...


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