GoneDiving
Senior Member
My new to me steel ex prawn trawler has been on a pole mooring essentially unattended for 2 weeks. Yesterday, I went to check on on it to find the 12v SLA 300ah house bank dead flat at 0.3v. The 400w solar panels and no frills mppt charger were not charging the batteries and were switched off.
My guess is that I have left a small 12v draw turned on and after 4 overcast days the solar has not kept up and finally the system has stopped charging when it turned itself off due to low voltage cutoff. The drain has then continued, pulling the bank down to near zero volts.
As the solar was not recharging the system, I made up some long jumper leads and used my dive boat to "jump start" the system. At 6v the solar reconnected and started recharging at 15 to 20 amps.
The only concern I do have is that when connecting the "jumper" cables I would get sparks when connecting the first (negative) lead BEFORE the positive was even connected to the house bank. Note both leads were connected to the applicable terminals at the dive boat end.
Why was there sparking with only one alligator clamp being connected? How was the circuit being completed?
Is "jump starting" from one boat to another's starter or house battery a good practice?
Thanks
My guess is that I have left a small 12v draw turned on and after 4 overcast days the solar has not kept up and finally the system has stopped charging when it turned itself off due to low voltage cutoff. The drain has then continued, pulling the bank down to near zero volts.
As the solar was not recharging the system, I made up some long jumper leads and used my dive boat to "jump start" the system. At 6v the solar reconnected and started recharging at 15 to 20 amps.
The only concern I do have is that when connecting the "jumper" cables I would get sparks when connecting the first (negative) lead BEFORE the positive was even connected to the house bank. Note both leads were connected to the applicable terminals at the dive boat end.
Why was there sparking with only one alligator clamp being connected? How was the circuit being completed?
Is "jump starting" from one boat to another's starter or house battery a good practice?
Thanks