Biggest battery to fit my 81 Caddy?

[btc3076]

I'm running a red Top in my Caddy,  no problems  so far





Battery Type:   Sprial AGM
BCI Group Size:   34/78
Cold Cranking Amps:   800 amps
Cranking Amps:   1000 amps
Deep Cycle/Starting:   Starting
Height:   7 13/16 in
Length:   10 in
Maintenance Free:   Yes
Reserve Capacity:   100 min
Terminal Type:   Dual Termimal
Voltage:   12 v
Weight:   41 lbs
Width:   6 7/8 in

[92EcoDiesel Jetta]

Nice! What did it cost?

I'm running a red Top in my Caddy,  no problems  so far





Battery Type:   Sprial AGM
BCI Group Size:   34/78
Cold Cranking Amps:   800 amps
Cranking Amps:   1000 amps
Deep Cycle/Starting:   Starting
Height:   7 13/16 in
Length:   10 in
Maintenance Free:   Yes
Reserve Capacity:   100 min
Terminal Type:   Dual Termimal
Voltage:   12 v
Weight:   41 lbs
Width:   6 7/8 in

[bbob203]

Nice! What did it cost?

I'm running a red Top in my Caddy,  no problems  so far





Battery Type:   Sprial AGM
BCI Group Size:   34/78
Cold Cranking Amps:   800 amps
Cranking Amps:   1000 amps
Deep Cycle/Starting:   Starting
Height:   7 13/16 in
Length:   10 in
Maintenance Free:   Yes
Reserve Capacity:   100 min
Terminal Type:   Dual Termimal
Voltage:   12 v
Weight:   41 lbs
Width:   6 7/8 in

 only 200 bucks

[homerj1]

Any thought about running two batteries?  I suspect that there isn't enough room on the pass. side. for another battery.

[8v-of-fury]

I have thought about it, tons of room depending on your setup. What does your passenger side look like? For me, I'd need only to move my washer bottle, and run a shorter intake with my cone filter.. possibly up in to the rain tray. One could run the biggest battery desired in the trunk with a pair of huge gauge cables running to the other battery.. For you in the bed, with a nicely done box.. Run the cables and some heat sheathing down the exhaust tunnel.. good to go.

Electricity always takes the path of least resistance, so the starter will still pull its majority from the native battery being the path is much shorter. If that battery should drop below what the starter wants to take then it will start pulling from the back battery. It is not an exact on/off switch.. but it is how it works more or less.


ps. I once had a person tell me that running two batteries would fry all the electrical in my car... and that running a 120A alternator in a car originally designed for a 50A would also fry everything and start fires... Really? This guy was a self-proclaimed electrical guru too...

[hillfolk'r]

Aah the old red top,those were the days.at my old generator job we used those and replaced them after 4 years for safety.i had tons of em and gave em to friends.i ended up buying one at the time and it lasted just shy of 11 yrs.amazing.im runnin a blue top i got at a job and its 4 yrs old,itll be ok another 4 probably.if i had to buy one i would but i keep getting them free.
the model pictured is nice,dual post,you can hook up extra accys easier.
it was 5 out the other morning and sooty didnt crank 2 seconds and was lit.it idled at about 39 to 42 rpms for about 3 minutes though.
best bang for the buck,optima.they are around 200-220@advance,try online somewhere else.they can be shipped ups ground they are termed dry.
now for my race car,im gonna use an odyssey i think the model is 680u or somethin.....its half the width of a lawnmower battery and hits with 680cca for 5 seconds.oh it weighs like 14 pounds..not a winter battery but for a dude lookin to lose weight in summer its ok.
i see them statr the big ol lycoming 6 cyl plane engines all the time,itll do a vw diesel in the summer

[92EcoDiesel Jetta]

Aah the old red top,those were the days.at my old generator job we used those and replaced them after 4 years for safety.i had tons of em and gave em to friends.i ended up buying one at the time and it lasted just shy of 11 yrs.amazing.im runnin a blue top i got at a job and its 4 yrs old,itll be ok another 4 probably.if i had to buy one i would but i keep getting them free.
the model pictured is nice,dual post,you can hook up extra accys easier.
it was 5 out the other morning and sooty didnt crank 2 seconds and was lit.it idled at about 39 to 42 rpms for about 3 minutes though.
best bang for the buck,optima.they are around 200-220@advance,try online somewhere else.they can be shipped ups ground they are termed dry.
now for my race car,im gonna use an odyssey i think the model is 680u or somethin.....its half the width of a lawnmower battery and hits with 680cca for 5 seconds.oh it weighs like 14 pounds..not a winter battery but for a dude lookin to lose weight in summer its ok.
i see them statr the big ol lycoming 6 cyl plane engines all the time,itll do a vw diesel in the summer

PM me if you still get free used Optima's. Maybe we can do some trading?

[theman53]

x2

[8v-of-fury]

Aah the old red top,those were the days.at my old generator job we used those and replaced them after 4 years for safety.

[btc3076]

Yep 200

Nice! What did it cost?

I'm running a red Top in my Caddy,  no problems  so far





Battery Type:   Sprial AGM
BCI Group Size:   34/78
Cold Cranking Amps:   800 amps
Cranking Amps:   1000 amps
Deep Cycle/Starting:   Starting
Height:   7 13/16 in
Length:   10 in
Maintenance Free:   Yes
Reserve Capacity:   100 min
Terminal Type:   Dual Termimal
Voltage:   12 v
Weight:   41 lbs
Width:   6 7/8 in

[hillfolk'r]

Unfortunately I don't work at that place anymore
I occasionally get one here and there where I work now but not like I did.
Do they still make the 800 u I think it was?
It has side and top post which makes it nice to hook up your accessories to, and the 800 is plenty.

[ToddA1]

A group 49 should fit without issues.  I think it was the same price, too.

My Passat TDI called for a 41 and i wanted bigger.  49 measures just under 14" wide... I could have easily gone 16" wide.  The terminals are properly oriented, although the battery needs to be shimmed about 1/4" up so it's not loose in the tray.  1000ca/875cca. 

I think I had a Deka AGM 34/78 that lived for almost 10 years.  Incorrect terminals, though.

-Todd

[hillfolk'r]

Hey 8v that electrical guru wasnt totally wrong. You should upgrade the charging harness to some fat 8 or 10 guage because yea if you have a 120 amp alt and the batteries ask for a lottA amps to recharge yes it will overload he factory wiring. You could probably cheat and run a fat cable from the alt to the battery and thatll remedy a potential burnup

[8v-of-fury]

Hey 8v that electrical guru wasnt totally wrong.

He didn't mean Alt-to-battery charging wire.. he meant the interior stock wiring.. lol! I was like yes,, because all of the sudden everything is now pulling more power than before haha.

[vanbcguy]

Hey 8v that electrical guru wasnt totally wrong.

He didn't mean Alt-to-battery charging wire.. he meant the interior stock wiring.. lol! I was like yes,, because all of the sudden everything is now pulling more power than before haha.

Lots of older American stuff routed the full charging current of the alternator through an in-dash ammeter (Chrysler stuff in particular)... So there definitely have been quite a few vehicles manufactured where his statement would be 100% accurate.  I've owned several of them!  On those vehicles dramatically increasing the alternator output either through additional draw or through a larger alternator could quite easily fry stuff, especially with the crappy bulkhead connectors they used to use.  I had a vehicle or two where we had to punch out the burned/corroded bulkhead connector pins and then rewire with some heavy gauge copper instead.

Our VWs don't have anything like that - they run directly from the alternator to the battery.  It's not a bad idea to increase the size of that wire either way, but if you are running a larger battery/alternator then it'd be almost a requirement.