Hi there! Our X-Type used the H7-790 CCA, can I use a bigger battery H8-900 CCA? Would it do any harm to the car wiring and components? Its width is the same, but the length is 1.5 inch longer which fit right in space without the box.

 

Thang, it should be just fine in the car. If anything, it should help things out as it is going to filter the noise from the alternator just a little better. The only time that it will be "hard" on the car is if you have to crank and crank the car before it will start. This will cause the alternator to have to work that much harder to return it to a full charge. So, the alternator is going to spend more time at 100% and this can cause a shortened life of the alternator due to heating. But, I would not worry about that.

 

Thanks Thermo, I know you always have the answer, now another question: With such a heavy battery, lift it up to put it in a snugly space is quite a job, if I put it in the right side corner in the trunk, beside I have to find a cable long enough to run to the engine compartment, is there any thing else I need? Do I just bolt the negative terminal to the body in the back and bolt the engine negative cable to the frame in the front? or do I have to run both pos. and neg. cable to the front? Thanks again Thermo and any body give any suggestion.

 

If you're running a longer cable from the trunk, you'll probably need a thicker cable /lower gage. I'd have a look at what the XJ cable standards are as some of those used to place the battery in the rear of the car.

 

Thang, you only need to run a new positive cable from the front to the rear of the car. You can tie the negative cable to the body of the car. Just make sure that you have a good connection point (ie, about 1" of surface on the connector to bare metal on the car. Any sort of resistance and you are going to see the outcome (how does BBQ kitty sound?).

As for cable size, assuming you are running 15 feet of cable, a 4 gauge wire is the minimum that I would recommend. That is going to be at the limit of what is deemed an acceptable voltage drop across a wire. Stepping up to a 2 gauge wire would be better.

 

You should run both the positive and negative cables to the front of the
car. Connect the negative cable to the engine block. You should not
depend on the body to carry such heavy currents. The existing engine
to body straps may not be adequate.

Pete.

 

Why do it at all?

 

Jagger, with the car running, the current going through the body of the car will be the same, regardless of where the battery is located/grounded. The only difference will be a few amps to keep the battery topped up and the current needed to restore the battery to 100% following a starting of the engine.

When you turn on the seat heater, that goes through the body of the car. The stereo goes through the body of the car. The headlights go through the body of the car. Now, how much of the car that it goes through is going to shift a little bit, but there is enough steel in the body of the X-Type that it won't affect anything. It would be a different story in say my 2012 XJ where most of the body is aluminum and it not being the best of conductors.

 

When he cranks the the car a lot current will flow through the body
of the car. That is why the heavy cable from the battery is bolted
to the engine and not the body. The current from the second battery
could be a 100 amps during starting. When the primary battery
fails then the full cranking current will run through the body to
the probably inadequate engine grounding straps.

I remember the days when most auto accessories were grounded
to the closest point on the body. On older cars like I had you
were forever chasing down bad grounds. That is why that
system is no linger used.

Pete.

 

Was wondering the same thimg. Just seems like a lot of work for......what benefit? Normal battery does a great job if everything else is working properly. Not there is anything wring with what you want to do, just maybe that I would not be that ambitious.

 

The idea of shifting the battery to the rear of the car is to get a near 50/50 weight distribution to the X-Type. while the battery may not seem like a major thing, it is a significant bit of weight. Moving it from one end to the other can help with letting the front and rear of the car both start sliding at the same time instead of having an oversteer or understeer issue. But then, how many people are pushing their cars to the point that this would make that big of a difference?

 

In that case I would run both cables. By all means a local earth strap too.

Clamp the battery down so that it is secure (in case the car is rolled for example).

 

Yeah, I understand the weight distribution part of putting a battery in the trunk, but in this particular case it sounds like the reason Than was going to do that was because the biiger battery was too heavy and too hard to maneuver into position. That is why I wondered why go to all that trouble just for that. Just get a regular OEM style battery as there seeemed to be little advantage to going to all that trouble with a bigger one.

 

OK I made other people wonder why would I do it? Here, since I read that the Jags. are susceptible to the battery voltage, and with higher CCA batteries will give the electrical system some slack and the battery life will be longer, but bigger mean heavier, like I said in the first post, carry up a 60-70lbs to put in a snugly space is quite a job for a small old guy like me (I might need a battery crane), so by the same time it benefit of distribute the weigh to put the big heavy battery in the back. As Thermo said it will slide both front and rear, even I don't drive that fast, but it could happen when the road is slippery, that what I thought. Thanks every body.

 

Why not just use a ctek or the like? Cheaper and a whole lot easier.

 

JagV8, what is ctek?

 

https://smartercharger.com/

 

Do not know how a more powerful battery will do any harm to a healthy vehicle's charging system. Have always used the most powerful battery that will fit in the space provided, with nothing but good results, in cars, trucks, and motorcycles.

 

Wingrider, the only "damage" that can possibly happen is with the heavier battery, this puts more stress on the battery tray and can potentially cause it to fail (say during an accident) where the normal battery may have remained in place.

As for benefits, there are two that I can think of. The bigger one being that the battery will filter the pulsating DC coming from the alternator better, leading to a more flatline DC for the car, making things last a little longer and the computers will appreciate it as they are not having to compensate as much. The other thing being that when the car starts, the voltage drop is not going to be as bad, so it will be easier on the components as they won't be pulling as much amperage (except for maybe the starter) and the motor will be spun faster, resulting in less time rolling the engine over with the starter (getting minimal lubrication).

I am like you, I like to get the biggest battery I can for my vehicles.

 

Cold weather sure makes them shine, when yours starts easily, and many others crank slowly if at all.