Batteries: 6 volt vs 12 volt, series vs parallel

[whoofit]

[quote source="/post/11361/thread" timestamp="1432592110" author="@david"]The perils of hooking up two 6V batteries in series to make 12V seems to have died. Let me drive a stake through its heart.

There is essentially no electrical difference between two batteries with 3 cells each hooked up in series to make 12V vs a single 6 cell 12V battery. Tens of thousand, maybe hundreds of thousand boaters use 2,4,6+ golf cart batteries hooked up this way and have none of the problems that fasteddie noted when he tried to charge two 12V batteries with a 24V charger.

I suspect that one or more of the cells in fasteddie's experiment were bad which when charged by a high output charger caused the current to skyrocket, heated the battery up and it was destroyed. This can happen whether you have 1,2,3,6 or 12 cells in a battery.

David

[/quote][p]Just to elaborate the likely scenario is an individual cell went to high resistance, saw reverse polarity because of it and overheated...[/p][p]
[/p][p]This can happen in parallel circuits as well. But in series we are feeding overvoltage on a battery by battery basis already.
[/p]

[fasteddieb]

[quote source="/post/11361/thread" timestamp="1432592110" author="@david"]The perils of hooking up two 6V batteries in series to make 12V seems to have died. Let me drive a stake through its heart.

There is essentially no electrical difference between two batteries with 3 cells each hooked up in series to make 12V vs a single 6 cell 12V battery. Tens of thousand, maybe hundreds of thousand boaters use 2,4,6+ golf cart batteries hooked up this way and have none of the problems that fasteddie noted when he tried to charge two 12V batteries with a 24V charger....

David

[/quote]David,

I made much much the same arguments when confronted with the allegation that there were hazards to charging two seperate batteries in series.

Anyway, I had one bad experience I wanted to share as a cautionary tale, is all.

[charliem]

[font size="3"]Hmmmm?

Strange GFCI interrupts and hot skin?

Mysteriously overweight tongue?

Exploding batteries?

Mineral Bluff?


Eddie, have you checked your water?  
[/font]

[fasteddieb]

Well, they do have these signs at the city limits:

[fasteddieb]

In the interest of full disclosure I did have a 12 V battery hooked up to a 12 V charger explode in my garage a few years back as well.

 One lesson I took from all of this is that battery boxes are a good idea, even when charging out of the vehicle.

[whoofit]

[quote source="/post/11429/thread" timestamp="1432659024" author="@fasteddieb"]In the interest of full disclosure I did have a 12 V battery hooked up to a 12 V charger explode in my garage a few years back as well.

 One lesson I took from all of this is that battery boxes are a good idea, even when charging out of the vehicle.[/quote][p]Wind up toys are still a good idea sometimes.[/p][p]
[/p][p]I had one blow. Was working on my girlfriends dads car. Set a wrench down and boom. I married her. He never did get over either me marrying her or blowing his battery.
[/p]