Dual battery answers

[davepl]

I was trying to figure out for the longest time what happened if you ordered BOTH the dual battery option and the HD battery option. Was the second one also an HD battery?

I decided not, so I'm running the big Delco Cadillac battery as main and the smaller R59 as the aux.

According to the Heritage center docs:

Batteries
- TP2 Aux: 45-amp-hr, 9 plate
- T60 HD Battery: 80-amp-hr, 15 plate

There's no mention of the TP2 Aux ever being the 15 plate battery, so I think my hunch was correct.

[Mike C]

That's cool info. You don't see a whole lot of dual battery setups. I added one to my Jimmy, and it's equipped with the dual Optima blue top option.

[Steve Hafner]

. . . .

I've wonder that, myself . . .

. . . would you get TWO heavy duty batteries ?

I guess not !!!

I'm working on having two in my truck right now.

I don't need two, so I'm going to have a " dummy " for the second one.

[Keith Seymore]

Correct.

TP2 gets you two standard batteries. Still that way today.

Incidentally, the dual batteries on a diesel are wired so both assist with cranking the engine.

The TP2 (gasoline) option is not configured that way; only the primary battery cranks the vehicle. The secondary battery is for running 12v accessories, like a camper or trailer.


K

[Keith Seymore]

Originally Posted by Mike C

That's cool info. You don't see a whole lot of dual battery setups. I added one to my Jimmy, and it's equipped with the dual Optima blue top option.

You've reminded me of another quick story:

During the squarebody era RPO TP2 was available only on pickups, not on Blazer/Suburban.

One day while I was at Flint Assembly I got a call. Someone from headquarters asked me to grab a secondary battery tray from lineside and bring it to the executive garage poste haste.

So I dropped what I was doing and hopped in a company vehicle, and drove from Flint down to the GM Building and ran that battery tray up to the 14th floor.

Turns out Roger B. Smith wanted a dual battery setup on his Suburban and was doing it one piece at a time. That's the closest I ever came to meeting him.

K

[SS Tim]

Dave, Take a look at your build sheet box 53.
Late last night I did a little digging and found a Cheyenne Super/30 build sheet that has both battery options and a big block.
Being a 72 it of course had side terminal batteries but the code "R89WY" could be interpeted as a R89W (the known T60 battery) and a production Y89 as the lighter duty aux. battery.
I'm not up on 59 series battery codes but I suspect there may be an answer for you there in that box 53.

[davepl]

I have TP2 and T60 options as well but box 53 reads R69Y5.

The R59 is 61 amp hr, 2900 cranking amps.
The R69 is 70 amp hr, 2150 cranking amps.

R59


R69


Y77


R89

[SS Tim]

Originally Posted by davepl

I have TP2 and T60 options as well but box 53 reads R69Y5.

The R59 is 61 amp hr, 2900 cranking amps.
The R69 is 70 amp hr, 2150 cranking amps.

Interesting and certainly "seems" right for a 70 truck.
As far as the box 53 breakout there is the possibility it is for a R69 and Y59 batteries.

Did you check the owners manual to see if it shows recommended replacement batteries for a T60 and or TP2 equipped truck?

The 71 Custom Camper brochure shows the following specs. for T60 and TP2 options.

In the end an email or call to Tom at Restoration Battery might dig something out of their data base.

[monte0185]

Any Chance I can get a few pics of how and where the secondary Battery tray is mounted? Trying to install a NOS one in a 68 Blazer and would appreciate it.

[Steve Hafner]

Originally Posted by monte0185

Any Chance I can get a few pics of how and where the secondary Battery tray is mounted? Trying to install a NOS one in a 68 Blazer and would appreciate it.

. . . .

Here are a few pictures of ORIGINAL trays, mounted on the driver's side core support . . .

. . . the last two were said to be from a 69 truck.

. . . .

[jocko]

Thanks for sharing Dave, I plan to do this at some point also - good info!