I saw this post: checking battery and charger earlier. I have a similar question...

I replaced my battery backup sump system with a Little Giant SPBS-10HF Battery Backup Sump Pump System in June of 2017.

I also bought a brand new Duracell Deep Cycle Marine battery.

Last weekend, when I was in the garage (where the sump is located) I saw the LEDs on the controller looked odd.. Only the 25% and 50% LEDs were lit (usually, it has 75% and 100% lit as well).

So, I took the battery out of the plastic box, uplugged the controller and disconnected the terminals (the Positive terminal had some corrosion/battery acid on it-- this bothers me) and checked the water level in the battery-- the plates were all submerged/didnt add any water

I cleaned up the terminals and connectors and reconnected everything. The controller lit up 'charging'. It also list up 75% and 100%.

I am wondering if I have a problem with the controller/charger or battery or both...

Not sure how to diagnose...

 

How old is your battery? Have you had your battery load tested?

With low voltage (like 12 volts DC) good connections are critical. The smallest bit of dirt or corrosion can have a huge affect. Thoroughly clean the battery posts until they are shiny. Also do the same for the inside of the battery connectors. Then re-connect. For an added measure you can also coat the posts and connectors with dielectric grease (available online or from auto parts stores) to help protect the connection from corrosion.

 

Hi! I should have specified-- the battery is also from June of 2017.

 

Hi, one other thing is to make sure the top of the battery case,handles etc are spotless, you can take a multi meter set at 12 VDC and put one probe on a terminal and drag the other probe across the top of the battery case ,you should not see any voltage.
May not be a problem with a 2017 battery but thought I would mention it.
Geo

 

thanks! I will try this check