We have a boat with 3 batteries installed and are using a Blue smart ip 22, 3 outputs 30 amp for charging the batteries. A few weeks back one of our batteries were dead and could not be fixed. I bought a new and after a while another batteri failed. We then startet looking af batteri draining to understand why the batteries suddently dies. We found out that there was no draing and charger showed all good and did complete steps bulk, abs, flot and storage with no problems and stood in floating mode. Inspecting the charger a bit more i saw that the voltage did change when charging state changes from one to another but amp said 0. I measured this with the Victron app and also with an multimeter. I then tested with another charger which said instantly 25 % battery capacity and started to charge with a lot of amps. So why shows the Victron charger all good despite batteries are nearly dead?. I found out! A fuse near the terminals were blown. After replacing fuse, the charger started to work properly.
My question is therfore, why do the charger show that all is good when i fact its not working?
The problem is when you are on a boat, its very important to be able to trust you charger and batteries or else you could get in serious problems!
Is this really just a bad design or bad luck?