Adding a 2nd Battery?

Dennis,

If comparing the warranty on a battery installed when a vehicle is built vs aftermarket one, the answer is that the OEM gets a price break for specing a shorter warranty term. Same for shocks and other items.

Why is it NEW car batteries only carry a TWO yr warranty but when you replace it with an IDENTICAL battery it carries a FIVE yr warranty??? Asking for a friend...:)....Dennis

Alan_Hepburn wrote:
...and like any socialist society, all the individuals will eventually balance out to the lowest common denominator. In other words: weak batteries will prematurely weaken good batteries...

I have seen no evidence of this in 15 years of doing it. Now batteries have multiple failure modes. SHORTED. yes a SHORTED battery will "Suck down" the rest of the set.. Don't matter if it's a week old (Had it happen) or 5 years (Never had it happen).. But the most common failure is what I call high resistance or loss of capacity... And in those cases the battery simply disparages and causes no damage.. Replaced 2 of those last month. Out of 3 (the 3rd passed load test with flying colors)..

So not As I said it's not a people socialist, it's a PERFECT socialist arrangement. Something not possible with people.

I've been doing this for a long time..

I had one battery (Car starting) fail within a week of purchase. .The identical replacement lasted many years.. Which goes to show "identical" is not always identical.

I've never had a bad battery in a parallel arrangement take down the others.

Yep, Unbelievable.

Only took 2 pages for a post about parallel batteries to get political.

wa8yxm wrote:
The batteries form a perfect commune.. The ultimate Socialist society.. (Works for batteries. I won't comment about where it does not work) in that when charging each takes what it needs and when working gives what it can.. they all remain at precisely the same state of charge relative to each other (If one is at say 90%. then all are) at all times.

...and like any socialist society, all the individuals will eventually balance out to the lowest common denominator. In other words: weak batteries will prematurely weaken good batteries...

I have to ask the OP... What brand/model of Class A only comes with one house battery and so small that running the furnace sounds problematic? :h

ScottG wrote:
get every last coulomb of juice out of a battery ..

Ooh.. don't see that word very often! good one

We had a floor sweeper at work that had wildly mis-matched batterys in it and it did fine.
If you're trying to get every last coulomb of juice out of a battery system then all the matching and extreme gymnastics is helpful. Otherwise, it's no big deal.

Plattpd,

If you parallel two 12V jars that are less than identical, your result will be way less than the sum of the capacity. How much less? That depends on many things, too many to go into here.

As a short term fix, it might be good, but carry a new box of baking soda. You may need it. I have seen very few battery explosions that did not involve jars in parallel.

For reference, for a time our coach had a single 4D house jar. It could run the heat all night if I did not start it until we went to bed. We now have a pair of GC2 (actually T105s now) and that will run the heat evening into the next morning, but they are done.

Matt