Battery FAQ battery bank

Re: Battery FAQ battery bank

I have no clue who the folks at Concord / Lifeline were, but that is total Internet BS. 90 % of what you read out there is either made up or Parroted from one site to another. Tell me how a 100 amp hr battery would have the same discharge capacity as a 300 amp hr battery, the 100 amp hr battery would be dead and gone and the larger one would still have 2/3 rds capacity left. The same goes for charging requirements in reverse. It's a recipe for disaster. Age, the worse that going to happen is the older weaker will drag the new down to their level, in a short amount of time.

Have I hooked a couple together in float service for the winter where there is no activity ?? Sure I have and have 4-5 that way that right now. This would be a different story. This is not even the smartest thing to do, one goes bad it'll cause a issue for them all. That said, they are in a place they are monitored daily and the charger has a fixed float voltage and limited capacity.

Oh , by the way, if you read it on a marine / boat forum should tell you that they know probably less that the RV crowd about Batteries. It's good for a Guy like me or wouldn't have a job.

I have many Battery stories over the years, a couple years ago I go to a guys boat and his battery bank was flatlined. He says he turned the Inverter off for the winter because the year before it used $15.00 of electricity and he thought he'd save some money. I said, you didn't turn off the DC loads and they killed your batteries. he's like yeah, but I saved the $15, $800 later he was still happy he saved $15, go figure.
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Re: Battery FAQ battery bank

Shadowcatcher wrote: »

My understanding is that it is fairly common to mix sizes on boats, I would assume because of size/location constraints. My view of electric current is the similarity to water, If you have two ponds of unequal size they will self level.

BUT this does not answer the question I posed, I need a web site or explanation that is easy to understand.

I btw agree with caraiboocoot, one of the responses given to what do you carry in your tool kit is too often responded to with "a credit card and a cell phone". You have folks with a $200,000 RV's looking for a free place to stay.

The devil is in the details, if your talking about using a smart combiner to charge multipal size batteries off a common source. There plenty of ways to charge at 12 V then combine to 24 V or charge at 24 V then split to 12v. The idea of having a bank of batteries then inserting a battery of different capacity in it is crazy, of course there uninformed people every where. As Coot said 5-10% difference, no big deal. If you want to test it, take your car battery and hook it to your deep cycle battery and see how it does next summer.

There a few Boat chargers that will also charge 3 different batteries at the same time with different chemistry's, different capacities and different voltage settings at once. I am trying to come up with a reason to have different capacity batteries on a boat that require a bank of different capacities that you'd charge. A Bass Boat might have trolling batteries that might charge with a dc-dc charger from the starting battery and motor. A big boat might have 2 starting batteries for each engine, a battery for the generator, a couple house batteries, a big bank or two for the Inverter systems. generally each one would have their own charging sources. Even with 21 batteries on my boat, there no mixed capacities doing any one thing, except working me to death.

I'v seen a boat or two in the last 50 years that had a 32 v and a 36 V systems in the day's before the modern diesel, Most of them were pushed off in a hole and burned years ago. Before there were battery started engines, there were gasoline starter engines you hand cranked and started first and then started the diesel main engines with a clutch system.
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