Victron Energy Blue Smart IP22 charger question

[Corvette joe]

Hey gang, quick question. I have 2 12v Lithium batteries hooked up in series for my trolling motor. Question is when I hook the charger up to the batteries, positive to positive, negative to negative, when I hook up the last negative to the second battery I get arcing. Can I use 1 ground for both batteries because they are hooked up in series? They seem to charge fine. Just waiting for the smart battery sense to arrive to confirm they are charging correctly. Thanks in advance

 

[sunshine_eggo]

Hey gang, quick question. I have 2 12v Lithium batteries hooked up in series for my trolling motor. Question is when I hook the charger up to the batteries, positive to positive, negative to negative, when I hook up the last negative to the second battery I get arcing.

Normal. You're connecting 24V to 0V. If you energize the charger first, and it's outputting something a few volts different, you'll get little to no spark.

Can I use 1 ground for both batteries because they are hooked up in series?

Your question is confusing. You may have 2 12V batteries, but you have one 24V battery. The 24V battery should be grounded. if you ground both 12V (-) to a common ground while connected in series, you will get a short circuit.

They seem to charge fine. Just waiting for the smart battery sense to arrive to confirm they are charging correctly. Thanks in advance

How do you envision the smart battery sense determining if they are charging correctly? SBS gives only voltage and temperature information. Yes, the voltage reading will be more accurate than the IP22 because the IP22 voltage reading is influenced by the output current, but probably not by a significant amount.

 

[Brucey]

Hey gang, quick question. I have 2 12v Lithium batteries hooked up in series for my trolling motor. Question is when I hook the charger up to the batteries, positive to positive, negative to negative, when I hook up the last negative to the second battery I get arcing. Can I use 1 ground for both batteries because they are hooked up in series? They seem to charge fine. Just waiting for the smart battery sense to arrive to confirm they are charging correctly. Thanks in advance

Do you have a 12V or 24V IP22? Is it a three output version?

To charge the 24V battery attach the positive to the positive and the negative to the negative. At the locations where you would draw from the trolling motor. Don't connect anything to the midpoint terminal.

 

[Brucey]

Your question is confusing. You may have 2 12V batteries, but you have one 24V battery. The 24V battery should be grounded. if you ground both 12V (-) to a common ground while connected in series, you will get a short circuit.

Which would be a possibility if he was using a three output IP22 which has three positive terminals and a single common ground.

 

[OzSolar]

I have several of the IP67 models and they always make a pretty healthy "pop" when I hook them after from being stored hooked up to nothing. Then when I disconnect them and move them to the next battery, within ~2 minutes or so of being powered down, they don't do that. I just assumed it was normal.

 

[l00semarble]

we need to know what specific IP22 charger you are using. Provide Victron part number please.