Batteries--series or parralel?

[k1vsk]

Like many things, this is largely a matter of opinion - there is no absolute answer to the issue of paralleling multiple batteries being good or bad.

There are some fundamental considerations which should influence the decision more than the fear of a shorted cell:
Would you rather lift, move or replace large 8Ds or smaller 6V batteries?
Will one bad cell lead to a total power failure or do you have a spare/emergency power source?
How unlucky are you?

[Bene505]

Following the spirit of the more advanced theme of Architeuthis' post, I often think that there's a place onboard for Edison batteries as part of the total capacity on board. Yes, they lose 1% of their capacity every day (and DON'T EVER OVERCHARGE THEM), but they last virtually forever. There are Edison batteries that are 50 years old still working perfectly.

The way to do it would be to figure out your daily usage, the amount you draw down on your lead-acid batteries each day. Then use Edison batteries for that load and keep your lead-acid batteries protected from any discharge cycles on typical days. The lead-acid batteries will last for decades, depending on how much you do draw them down. And since only the typically-used portion of your bank is Edison batteries, you won't be appreciably impacted by the 1% loss per day drawback.

Edison batteries are what the WWII subs used to provide power when underwater. They were also used by railroads.

Regards,
Brad

[Architeuthis]

Originally Posted by Bene505

Following the spirit of the more advanced theme of Architeuthis' post, I often think that there's a place onboard for Edison batteries as part of the total capacity on board. ...

Oh yeah! I would love some of those but as I recall cost and size work against them, banks get very large and heavy compared to lead acid. They also outlive the equipment they power so industry is not that keen on them.

But heavy is not so important in a boat so might be worth it if designed in.

The only ones I've seen have been when they are removed from old equipment. Some of those are dead so they can be killed but some were still kicking after decades in use. You don't see much of that these days.