2002 Grand Caravan battery issue

Twice in the last couple of weeks someone else using my van has gone to start it and been unable. Engauging the starter only resulted in rapid "clicks".
Attaching a battery booster both times easily started the car and all was well.
Yesterday (the second time) I grabbed a volt-meter along with the booster pack. The battery was reading 10v at rest, and dropped nearly to 9 under load.
I boosted it and the car started, drove it home and put it on a charger -- where it drew 6-8 amps for a couple of hours.
This morning I checked it at rest in the cold before doing anything and it read above 12v as it should.
With the engine running there is over 13v going across the terminals, so the alternator etc. seem to be fine.
I was sure there was a bad cell in the battery (only 37 months old, OEM), but then this morning seeing 12+V confuses me. Especially since my wife had charged her cell phone overnight using the car battery, I had expected it to read low again.
Thoughts? And would it be worth exchanging for another MOPAR battery with whatever proration credit or just go to my favorite battery store?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
just goto someplace like walmart or autozone they offer free install service, usually walmart is cheeper, but you will get a better quality and a lifetime warranty at autozone.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Actually I am perfectly capable of installing a battery and will use Costco as their price is comparable and service is beyond either walmart or autozone.
I was wondering if anyone knew the residual value of the OEM battery (38 months), and any other ideas on why it has twice run down so low. but then in even on a cold morning appeared okay.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
There is no residual value on an oem battery. It is covered 12 months under the basic warranty. then you are on your own. Get the Optima Redtop from Costco. best price around. And the regular batteries are the same as the other parts stores. There are only two main battery manufacturers. And they are very similar in quality. But they are only lead/acid batteries anyway.
-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have you taken the terminals off the battery to clean them? this could be your only problem.
Glenn Beasley Chrysler Tech
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

to
rapid
nearly
charger
and
so
my
had
whatever
be
Both (pos & neg) terminals are clean and tight.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Replace the battery.
Glenn
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.