Engine/Transmission (1998.5 - 2002) Why 2 batteries?

[tmckenzie]

Why do the 2nd generation and up trucks have 2 batteries? I was looking at mine the other day and they were 750 CCA each. Friends 92 12valve has one 1100 CCA. What makes the difference that requires my 24valve to have the extra juice? I was looking at options for air intakes and was wondering if I could loose one and convert to one high CCA battery? Anybody done this and whats the pros and cons?

 

[bmoeller]

Given your from N. C. , depending how cold it gets in the winter, you could probably get by with one big battery. If I remember right, I did see some posts that some people have done that when installing a different air filter setup.

 

[WebCrush]

my '95 12 valver has two batteries.

 

[tmckenzie]

Hey Adam,

I wasn't sure about the 12vavle 2nd gens but what would make the difference between the 92 12 valve and your 95, aren't they practically the same motor?

 

[WebCrush]

beats me, I'm a prime newbie with only 200 diesel miles before I blew my transmission.



MY guess about the dual batteries would be related to the grid heater and starter ampage.

 

[Big_Daddy_T]

750+750=1500cca. also the reserve is the same 2x140mins is 280 mins. The grids pull excessive amounts of juice. And the colder it gets the motor needs more juice to turn over. I think at -30 it takes 350% more juice to turn the motor over. Add the grids and your gonna need lots of amps.

 

[BarryG]

At least on my 01 24valve those batteries are mainly used for the grid heaters. There are two of them and if I recall they pull 95 amps each.

 

[JWhitcomb]

I am under the impression that two batteries will not give you any more power but will give you a reserve of amps in case you need it due to cold weather hard starting. Am I right here?

 

[Deezul1]

If you dont have cold weather then starting is ok with 1 battery. I know several guys that have removed the second battery and dont have any trouble as the grid heaters arnt needed in mild climate

 

[Thomas]

Two batteries will give you more power (watts). Power (in watts) is equal to volts X amps. The greater power comes from the ability of two batteries to pump out lots more amps.



The power ratings (model year 2000) of the gasser starter motors are 1. 4 kilowatts (1. 9 horsepower) and for the Cummins 2. 7 kilowatts (3. 6 horsepower).

 

[Gary - K7GLD]

Two batteries in parallel will give double the peak power, and for twice as long as a single battery - in cold climates where the grid heaters are used frequently, 2 batteries are a nice feature, as they are when lots of added power-draining goodies are likely to be attached, as in the case of towing RV's etc - and in my case, my Amateur radio stuff draws LOTS of current, so I'm real glad to have 2 batteries, and when they need replacement, will probably go with 2 more of the largest capacity I can find...



In warmer climates, and where additional accessories aren't in use, a single battery works fine, as it did for over 10 years in my '91 Dodge... But THAT was a BIG battery too...

 

[RO'neal]

I needed room where the pass side battery is to install my air compressor so I relocated the battery to the bed. It was supposed to be a temp spot until I had time to make a better place for it but I think it will stay. I used a marine battery box and didn't have to drill any holes in the bed or anything. I just routed the cables up through the tie down holes in the front corners of the bed. Just my $. 02

 

[BSowers]

Has anybody thought about isolating the two batteries and having one just for the grid heater and the other for the rest of the truck. The idea here is so that if the grid heaters really suck the energy there is still full power for the starter.

What about a good, low price for an isolator for these rigs?



Brian

 

[TomGolden]

Originally posted by RO'neal

I needed room where the pass side battery is to install my air compressor so I relocated the battery to the bed. It was supposed to be a temp spot until I had time to make a better place for it but I think it will stay. I used a marine battery box and didn't have to drill any holes in the bed or anything. I just routed the cables up through the tie down holes in the front corners of the bed. Just my $. 02

Pictures please!!!



Thanks

 

[BSowers]

My question actually pertained to JUST the two truck batteries... . Why not isolate the two so just one is for the grid and the other is for the cranker.

 

[bighammer]

Why not get rid of the extra battery and grid heaters all together? Then you could use a shot of ether if needed.

 

[TomGolden]

ether



I know the biggest problem with ether in our engines is the chance of it detonating if the grid heaters are on as the ether flows past them, but you can grenade the engine itself on ether too. Yes, I carry a can in my toolbox, but if I ever actually have to use it..... I hope it's a short walk to the nearest hotel so I'll have a place to spend a few nights until a new engine can be installed... .

 

[BV]

2 batteries

The new body style with a lower hood design could be one reason and another is the ever increasing power using electronics and last, maybe for weight distribution.



A battery isolator is an idea but it wouldn't be a cheap one to do it right with the alternator putting out over 100 amps.

 

[15w40]

I read somewhere that the grid heaters go off when the engine is cranking. I think it is the programming in the ECM that turns them off to allow maximum current available from the batteries for starting. Adding a battery isolator to separate the battery to the grid heaters and the battery to the starter might not be such a good idea.

 

[PRout]

Adding an isolator is just something else to go wrong. Its a fix where there is no problem. There is no reason for it unless you are pulling juice while the motor isnt running, and want to keep one batt charged for starting.



Another thing to consider if you plan on removing one batt is that you will wear the brushes in the starter faster. Using one battery means less volts to the starter under a load, which means its going to pull more current to use get the same power. This definitely will case the starter brushes to wear faster.



This is usually seen when people replace their automotive style batts with deep cycles. Deepcycles run at a lower voltage, and are a bit harder on starters.



Its not going to immediately kill your starter, but will take life off of it. Maybe 20% - something like that. I still like the deepcycles though, and dont mind replacing the brushes.



If youre not in a cold climate, you probably wont miss the second batt, but it will turn over slower on starts.



If you want, disconnect the ground on the second battery so you can test it for awhile without the current from that batt. Its a safe way to take it off-line to see how it works without it.