Not convinced the Noco is working

[shortroyd]

I have a Noco Genius 5 that I wired direct to the house battery.

When I plug it in and watch it over the course of a day with the batteries turned on, it will eventually get to about 13.0V, sometimes up to 13.2V.

I leave it plugged in and turned on all week (battery switched off). Next weekend I check and the batteries are down to 12V, sometimes 11.8 or so.

I was expecting it to maintain them around 13V. Is this normal?

Next time I am on the boat I will get the details of the batteries in case that makes a difference.

 

[Judge]

Something is going on..... 11.8V is basically a 0% State of Charge with no load on the batteries.

Do you have wet / flooded batteries or AGM (or something else)? How old are your batteries?

If you have AGM, you want to make sure you have that selected on the charger. Otherwise it will try to equalize the batteries occassionally and the higher voltage used to equalize wet / flooded batterues will hurt AGM batteries over time.

If the charger is operating normally and the batteries are fully charged, the Float Charge Voltage should be in the 13.4V - 13.6V range.

When the charger is in the Adsorption mode you should be seeing a little over 14V.

 

[tdonoughue]

First thing I would try, however, is unplug it and disconnect it from the batteries. Come back the next day and hook it all back up. I had mine (Minn Kota, tho) do something odd and when I disconnected it entirely, everything was good again.

 

[shortroyd]

They are Interstate wet cell batteries, they came with the boat, about a year old.

I believe this is the starter battery but not sure what the house battery is.

I used the Noco eyelet connectors to wire it direct to the house battery (black).

 

[shortroyd]

Come to think of it, maybe the issue is where I am reading the voltage. I am going off the Connext screen shows the voltage of both batteries. I notice a USB port I wired in always shows a different voltage - usually 0.2-0.3v higher than the Connext screen. Maybe I have enough voltage drop between the batteries and the Connext that it’s not reliable.

Next time I go there I’ll hook up a multi meter direct to the terminals and see what it reads.

 

[lazergeek]

Make sure you check voltage with all accesories turned off too. full charge on good battery will show 12.8 volts.

 

[Bottom Bracket]

Disconnect all wires from the house battery except the charger. dsvr thingus off. I use the alligator clips. Works for me....

 

[Bruce]

Why do you have a single battery charger when you have two batteries?

Get something like this and charge both batteries. NOCO - 2-Bank 10A On-Board Battery Charger - GEN5X2

Your batteries should be at 12.6 volts when fully charged.

Trying to charge dissimilar batteries in parrallel is not going to work well even if you bridged the positives for charging. They need to be charged independently.

This is how my batteries are setup. I run a refrigerator from the batteries 24/7. I am on my 10th summer on the same pair of AGM group 31 batteries.

https://jetboaters.net/threads/my-unusual-alternate-dual-battery-setup.5632/