Check those Delco batteries

[Mark Rinker]

I am a fan of Delco batteries, but often forget that some over-the-GM-parts-counter replacements (http://images.wrenchead.com/smartpages/partinfo_resize/DUS/78-7YR.jpg) may require periodic maintenance.

The other day, I popped the caps and found them to be slightly low on water. Not suprisingly, the passenger/firewall battery was a little lower than the driver/headlight side, most likely due to extra heat soak it receives.

Added ~1pt of distilled water across both batteries. They have been in service about 18 months.

[More Power]

Hey Mark, Are you using batts with removable caps?

I've not attempted to remove the caps from the original (9+ year old) ACDelco maintenance-free batts in my 2001.

Jim

[Mark Rinker]

Yes - the latest set of OEM Delcos (P/N 79001632) I purchased at my local GM parts counter in fall 2008 have removable caps (http://images.wrenchead.com/smartpages/partinfo_resize/DUS/78-7YR.jpg). They are 6yr batteries with 675 cold cranking amp rating.

OEM (sealed, maintenance free factory Delcos) battery life with constant towing/hauling, resulting in higher underhood temps - combined with winter snowplowing duty (lots of battery drain at low RPMs) averages about 36-48 months in my experience. I have purchased 3 new over-the-counter replacement sets with removeable caps for the 2001, 2002, 2006 Duramax trucks listed in my signature block below. All three trucks were used for year around towing, and plow truck duty.

After a quick review of the warranty information here http://www.acdelco.com/html/bn_battery_warranty.htm?c=eNews06_APR_GM_battery_w arranty_txt , I should probably have the 7yr batteries, for free replacement out to 50 months, rather than 30 months, based on my replacement history. Here is the replacement pro-rate table: http://www.acdelco.com/parts/battery/battery-warranty.jsp

[DmaxMaverick]

All GM OEM batteries for light trucks and cars are NOT serviceable. Been that way for nearly 30 years now. They have caps, but are buried under a sticker and recessed in the case, and are not intended to be removed (they are lock-tabbed in place). What you get over the counter at the GM dealer may or may not be OEM. Delco offer several "types" of battery replacements. If you have a non-OEM battery with service caps, it is a very good idea to check them periodically, more often during summer months.

[Mark Rinker]

Sorry for any confusion.

These are Delcos, but I they are not 'OEM' - i.e. they are replacement Delco batteries, NOT 'OEM' or sealed/maintenance free like the first set from the manufacturer/GM factory.

That was my point - that it is easy to FORGET to check Delcos that are not sealed (http://images.wrenchead.com/smartpages/partinfo_resize/DUS/78-7YR.jpg), when we become accustomed to the first set of sealed, maintenance free batteries.

I believe there is an advantage for some Duramax owners, especially those from HOT southern climates, or those that tow heavy frequently, to have removable cap batteries so water can be re-added throughout the life of the battery. I have seen OEM Delco sealed units weeping from the vent (most often on the passenger side battery) and there is no way to replace that lost electrolyte. Not suprisingly - that battery tends to fail first, of the pair.