Question about power setup.

[Ceeze90]

Hi I am building a new system for a 99 Tahoe. I’m 90% sure it’s gonna be 2 crossfire c7 18s. I’m between two amplifiers, either a crossfire 4K or the crescendo 4K. Is one amplifier better than the other? Also I’m looking at a 370 alternator, will one xsD3400 under hood and one in the back be sufficient or should I get two in the back? 

[stingray72]

skip agm batteries and get this it will take up less room and weigh less and handle your power very well.  Youll need to delete your front battery though and run the lithium in the trunk  They dont like mixed battery chemistry's and excessive heat.

 

https://store.soundsolutionsaudio.com/ces-custom-electric-service-40ah-lto-battery-cased-lithium-10-spot-terminals-actively-balanced/

[Ceeze90]

2 hours ago, stingray72 said:

skip agm batteries and get this it will take up less room and weigh less and handle your power very well.  Youll need to delete your front battery though and run the lithium in the trunk  They dont like mixed battery chemistry's and excessive heat.

 

https://store.soundsolutionsaudio.com/ces-custom-electric-service-40ah-lto-battery-cased-lithium-10-spot-terminals-actively-balanced/

How many of these batteries would be sufficient for about 4K, just one? Also would there be any other equipment needed for a setup using lithium batteries. I’ve never used them. Thanks for the recommendation also. 

[Dafaseles]

In my opinion, you'd be happy with either of those amplifiers. 

If you insist on going AGM, I'd go at least 3. That's a lot of space. Lithium is a favorable alternative. 

That battery with that alternator would most likely be plenty, but they do make an 80ah version to for just over $1000. I don't know your budget though. 

What year Tahoe? If you have a 2006 or above, you might have a voltage management system and that will change how you wire your grounds. 

[Ceeze90]

1 hour ago, Dafaseles said:

In my opinion, you'd be happy with either of those amplifiers. 

If you insist on going AGM, I'd go at least 3. That's a lot of space. Lithium is a favorable alternative. 

That battery with that alternator would most likely be plenty, but they do make an 80ah version to for just over $1000. I don't know your budget though. 

What year Tahoe? If you have a 2006 or above, you might have a voltage management system and that will change how you wire your grounds. 

It’s a 1999 Tahoe. If that one battery would be good for me then I’ll definitely look into it. As it would be cheaper and less space. I just don’t know what all would have to be done. As I’ve never used lithium before. 

[Dafaseles]

I was a little intimidated by the whole lithium thing as well, but it's easy once you dive into it. 

First, you can't put lithium under the hood. It gets too hot. 

Second, you shouldn't mix battery chemistries. Only use lithium, or only use AGM, or only use lead acid, so on and so forth. That battery is an LTO. So if you want to add a second battery down the road. You should only use lithium LTO, not lithium Lifepo4. Different chemistries. They have Different resting voltages, so with the truck off, they'll do nothing but leach of each other, trying to balance themselves out, and it can be detrimental to the lifespan of the batteries. 

So, what you have to do with lithium is run a battery delete under the hood. With that year truck, you can just do the big 3 like normal. You'll need 2 runs of 1/0 from the alternator to the battery delete, which will be where your stock battery sits. There are different ways to achieve the battery delete. I used a battery terminal bolted to a piece of wood. I've seen people use fused distribution blocks, I've seen people use solid distribution blocks. LAF even has an empty battery case you can use. Basically, you'd attach your alternator to that, along with the vehicle stock electrical, then from there, 2 runs of 1/0 back to the battery. Then just ground to the frame like you would if it where under the hood. 

Now, I would fuse the 2 runs of 1/0 for safety. They will be running wherever you put them, but I'm guessing they will be hidden (like 99.999% of builds). So 1/0 OFC is rated to usually handle about 350 amps of current. So, if you're using 1/0 OFC, as close to the battery delete location as you can get, the closer the better, you'd use 2 350 amp fuses. Then, as close to the battery as you can get, you'd use 2 more. Because electricity isn't linear, it'll move in both directions, you have to fuse it in 2 locations so the cable between those 2 sections is protected. 

[Ceeze90]

4 hours ago, Dafaseles said:

I was a little intimidated by the whole lithium thing as well, but it's easy once you dive into it. 

First, you can't put lithium under the hood. It gets too hot. 

Second, you shouldn't mix battery chemistries. Only use lithium, or only use AGM, or only use lead acid, so on and so forth. That battery is an LTO. So if you want to add a second battery down the road. You should only use lithium LTO, not lithium Lifepo4. Different chemistries. They have Different resting voltages, so with the truck off, they'll do nothing but leach of each other, trying to balance themselves out, and it can be detrimental to the lifespan of the batteries. 

So, what you have to do with lithium is run a battery delete under the hood. With that year truck, you can just do the big 3 like normal. You'll need 2 runs of 1/0 from the alternator to the battery delete, which will be where your stock battery sits. There are different ways to achieve the battery delete. I used a battery terminal bolted to a piece of wood. I've seen people use fused distribution blocks, I've seen people use solid distribution blocks. LAF even has an empty battery case you can use. Basically, you'd attach your alternator to that, along with the vehicle stock electrical, then from there, 2 runs of 1/0 back to the battery. Then just ground to the frame like you would if it where under the hood. 

Now, I would fuse the 2 runs of 1/0 for safety. They will be running wherever you put them, but I'm guessing they will be hidden (like 99.999% of builds). So 1/0 OFC is rated to usually handle about 350 amps of current. So, if you're using 1/0 OFC, as close to the battery delete location as you can get, the closer the better, you'd use 2 350 amp fuses. Then, as close to the battery as you can get, you'd use 2 more. Because electricity isn't linear, it'll move in both directions, you have to fuse it in 2 locations so the cable between those 2 sections is protected. 

Hey thanks that’s what I was unsure about was the whole delete situation and how to connect the alternator and stock electrical. So I would ground the battery in the back of the vehicle? What about an engine ground? Thanks for the help. 

[Dafaseles]

So, there's different ways to do it, it just depends on how crazy you want to go. If I'm wrong about anything, or anyone has something to add, please correct me or add information. We can all stand to learn right?

Some people will actually do a run of huge cable from the negative post all the way to the alternator ground, then alternator ground to engine block, then engine block to frame. Others, just negative to frame, then engine block to frame. Technically, the alternator is already grounded to the engine block through the bracket, but some people like that added cable to the engine block. Some might actually go alternator to frame as well. 

You might already know, but if you don't, your alternator is basically where your electrical system starts and ends. So technically, you don't have to ground anything to the frame. But if you do ground anything to the frame, you need to upgrade all your grounds in order to stay away from bottle necks and to make sure your electrical flows freely throughout the vehicle. People generally ground to the frame because it's solid metal, so it's a good on that front, and it's easier than sending huge, let's say 4/0 cable, or multiple runs of 1/0, all throughout the vehicle and then grounding all that back into the alternator. Unfortunately, I have a 11 Silverado and have to deal with a voltage regulator controller that doesn't like it when you ground to the frame. So yeah, I have to send 2 runs of 4/0 from the back and ground them to the alternator, then also sending a 1/0 run from the negative post to the front, sending it through the stupid little donut (VRC) then into the engine block. But I don't think a 99 has that, so that's a plus. 

[Ceeze90]

Hey thanks again for all the information. I’ve been watching videos trying to learn more about the lithium batteries. 

[Ceeze90]

Mechman sells a harness that will raise the charging voltage to  15-15.3 volts. Is that required for the lithium lto battery?