Dual battery setup

[cnadler3]

Hello everyone!

​I've read through the majority of the threads regarding this topic, but would apprecaite a sanity check that my understanding is correct. I currently have two batteries and a perko switch configured in the following manner:

cable from starter going to common terminal
terminal 1 and 2 on Perko going to different batteries
ground from engine going to battery 1
cable connecting both negative battery terminals
2 positive leads from amps going to battery 1
2 negative leads from amps going to battery 1
1 positive lead from hydraulic pump to battery 1
1 negative lead from hydraulic pump to battery 1

This all works, but I think it's not ideal. Based on what I've read, it be recommended to use a 2ga cable to connect a bussbar to the common terminal on the perko, then connect everything that is now connected to battery 1 to the bussbar. Then mount another bussbar, connect the ground coming from the engine and then connect the rest of the negative cables there, still leaving the cable between the two negative terminals on both batteries.

With this config, everything will run off of which ever battery the perko switch is set to. I'd designate one of the batteries as a backup, but still leave it switched to all when the engine is running.

Thoughts?

Thanks!

Chris

 

[NicoPags]

Yes you are correct, you can run from COM to a buss bar, however use a fused block instead for your positive. Unless you want to individually add a fuse to each accessory. You can use a buss for the grounds.

This topic, almost identical, has been covered many times within this forum

 

[cnadler3]

I don't understand what you mean by a fused block. I am looking at this for the positive leads

http://www.amazon.com/Blue-Sea-Syste.../dp/B000K2MA9M

Both amps have fuses in them, not sure about the hydraulic pump. And wouldn't using a buss bar be similar to what I'm doing now, just cleaner? On second thought, I'm not sure the buss bar for the negatives is necessary as the grounds don't need to be battery specific, meaning I can just connect the accessories to either battery and the positive matters more.

 

[NicoPags]

you're correct about the grounded accessories.

iBoats sells exactly what you need for a cleaner set up. the link you provided is marketed as a grounding bar, and yes you could supply power to it and feed off of that. With an electrical background, no one would recommend. You want to individually protect your accessories with their own fuses. Furthermore, what if there was an issue and an unprotected accessory shorted, not only would it be hard to isolate your issue, but could damage the whole system. Any job worth doing is worth doing right.

http://www.iboats.com/Fuse-Block-AT...241047--session_id.882220065--view_id.1263668

 

[cnadler3]

So I decided to leave the grounds connected to the batteries and ordered this:

http://www.amazon.com/gp/aw/d/B01BV1MS1K/ref=mp_s_a_1_2?qid=1463445956&sr=8-2&pi=AC_SX236_SY340_FMwebp_QL65&keywords=fuse+block&th=1&psc=1

I also ordered a 12 inch 2ga cable to connect it to the common terminal on the perko switch. This will leave me one extra terminal for growth, look ok? Also, what size fuses do you recommend for the accessories? Both amps are around 500w and not sure the power draw from the pump.

Thanks!

 

[NicoPags]

To determine fuse you just need to know what the current draw is on your accessories. Should be in the manufacturer specs on the respective accessories

 

[cnadler3]

Well, received the fuse block today and found that is only recommended for 10awg....one of the amps has 8awg and the other is 4awg. Do you have another solution you recommend? If the amps have a fuse inline (within 12 inches of battery), couldn't I just connect them directly to the common terminal? I'm not sure about the hydraulic pump, recommended to have a fuse inline as well? It is connected directly to the battery now without an inline fuse.

 

[NicoPags]

No Title

You can still use 8 and 4 awg on the fuse block. Its what I use on mine (same fuse block). If anything, its just overkill. Your amps could connect directly to the com as they are protected but your negating the purpose of the fuse block. Anything that isn?t feeding power from the fuse block. Should have a separate fuse installed. Take a look at this diagram I've seen on this forum. I think it was from the member ALLDODGE