Battery Problem

[Midnightsun]

Seems like no matter what you buy nowadays just does not seem to last any more. Oddly enough we have an electric fork lift at the shop, Original batteries are 10 years old now and the lift still performs flawlessly. Even the service tech cannot figure out how the batteries are holding up so well after all this time. We do top of the water every week and plug her in over the weekend so they are definitely not neglected.

Will find out late next week what is wrong with the set I am replacing.

[bud37]

I installed a house bank of Rolls Surrette 4x6 volt in the last boat, it was nice stuff....monitored with a Victron BMV702.....bonus, I think they are from the east coast .

[KandJ72]

Something I noticed looking at the specs of the batteries you posted, what stood out to me is the recommended charge rate "50" AMPS per battery, so it's very possible your 12volt 10 amp (5 amp per battery) is somehow the cause. Just too slow/low of a rate of charge. It might be causing the batteries to sulphide up.

[Midnightsun]

Source of the post Something I noticed looking at the specs of the batteries you posted, what stood out to me is the recommended charge rate "50" AMPS per battery, so it's very possible your 12volt 10 amp (5 amp per battery) is somehow the cause. Just too slow/low of a rate of charge. It might be causing the batteries to sulphide up.

The 10a circuit is only being used as a top off during the times when 220v shore power is not available on the hard. My normal everyday unit is a 50a. I am at the boat now with new batteries in hand. Voltage reads 11.5 on the house bank right now. Will be swapping out today.

[Midnightsun]

Fixed. You learn something new every day. Turns out the breaker from the charger output to the house bank was tripped. Oddly enough this caused the current to somehow show negative input on my SOC meter which is what threw me off. even with the other charger hooked directly to the bank the isolator somehow took away this charge and my SOC meter with charge was showing negative input. I really do not comprehend what went on but once the breaker was reset the main charger now showed +48 amps into the battery via the SOC meter and voltage climbed rather quickly. Looks like I my have a 870a battery bank now for the house assuming the batteries are still in decent shape.

Bottom line is its fixed and we can now go on to enjoying the boat.

[Midnightsun]

Learned some new in all this mess. I have a 50a charger as a standard charger on board and an aux 10a charger for those times when only 110v is available usually on the hard. When both are on I only get an input of 10a to the house bank, Shut down the 10a charger and the main charger now outputs 43a. Hmmm, what happens with solar? Does the solar input confuse the large charger? I always thought they were smart enough to adjust accordingly and output the max, obviously not the case.

[Viper]

I've come across charge conflicts before that end up shutting down chargers. A prime example is running the genny with the charger on and one of the outputs is charging the genny battery at the same time the genny is charging its own battery. Not every charger can handle that, some will shut down when they see a conflicting charge. That's the only condition I've seen that happen in, probably because you rarely see two charging sources running at the same time. If the ability exists to do that, one source should be shut off.

[Midnightsun]

So what happens while underway when using the generator. You end up with the main charger now getting power and supplying a charge. Alternators from both main engines and generator are also active and then throw in solar panels that are trying to charge. Yes shutting of the main charger and the solar is definitely an option however never heard of anyone doing this.

In our case we rarely use the gen while underway unless we need the stove/oven to prepare a meal so I see no purpose in shutting off the main chargers. I am going to start shutting down solar when connected to shore power or under way though. Pretty simple to do as I have a 50a breaker that runs the solar system.

[bud37]

Not sure exactly how you are measuring this......does your meter have a shunt and if so, that would require all the grounds to be in the right places or the readings are not accurate and will be misleading. That said IMO I think your smart charger is doing what it was designed for, it sees some resistance and voltage created by the little charger as a good battery then shuts down. You just appear to have a draw and the little charger can't keep up as you found out with the big one off. I wonder what tripped that charger ?

Just because it is a 50A charger doesn't mean you will get 50A all the time.....you will only see the max when the charger is connected to a dead bank, anything more and it ramps down quickly as resistance increases.

[Viper]

When I say some chargers shut down, I'm not talking moving into a float cycle for example, they completely shut down, no output on any leg and all indicators are either off or doing weird things. Even after removing the conflicting charge, it seemed the only thing that would put things back to normal was rebooting by shutting the power off to the unit.

Unless you're sure your charger is okay with seeing conflicting charges, don't hook it up to the genny battery as that will trigger a conflict. The genny should be able to maintain its own battery but if you want to hook up the charger to it, you can hook up a switch to shut down that charge leg when the genny is operating. If you run your genny often though, you shouldn't have to hook up the charger to the genny battery.

I don't leave anything switched on at the panel if it's not in use at the dock or underway. I turn on one thing at a time when it's needed. Leaving all the breakers on is a certain way to cause spikes when source power is finally applied which can take out sensitive electronics. This is why surge suppressors are a good idea. When I have a power failure at home, I go to the panel and shut off most breakers until the power comes back on and then I turn on one breaker at a time. When things fail after a power failure, it's not when the power shuts down, it's when it comes back on and everything is trying to turn on at the same time, they'll either suffer from a spike or a brownout, neither is good.