Multiple connections to pos terminal on battery

[Tigerbug]

I tried the search function but came up empty. Not sure I'm using the best search words.

I have multiple connections made to the positive terminal (bus) for multiple amplifiers, lighting, battery tender for when it is flat towed, as well as trailer tow lighting harness. As a result I'm stacking a number of pos rings onto these posts.

I wondering how many is too many?

I'm not great with electrical but wondering if anyone has added a secondary bus bar for spreading out some of these connections. Is this an option?

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[Bschurr]

You can stack all you want - the issue is usage. What is the total amperage draw of the accessories that you are using together/simultaneously? And this needs to be measured against the rated amperage of the battery - that’s how you can determine how much is too much.

 

[HighVelocity]

Think of the length of the studs as a dare, not a limitation.

 

[Tigerbug]

You can stack all you want - the issue is usage. What is the total amperage draw of the accessories that you are using together/simultaneously? And this needs to be measured against the rated amperage of the battery - that’s how you can determine how much is too much.

I understand the limitations for amp draw on the battery. I have been reading on a few automotive sites for 12V electrical that "stacking" can create issues. I'd have to find those sites again but I thought it had to do with resistance. Here is just one of many that I found searching online

Resistance is the concern. By stacking ring terminals you create multiple contact areas where current passes through. These areas will go through thermal expansion and contraction with current flow. This will result in your connection loosening over time increasing resistance.

I am curious to my other question if anyone HAS added a positive bus bar off the pos battery post in addition to what Ford has already provided?

 

[flip]

I understand the limitations for amp draw on the battery. I have been reading on a few automotive sites for 12V electrical that "stacking" can create issues. I'd have to find those sites again but I thought it had to do with resistance. Here is just one of many that I found searching online

Resistance is the concern. By stacking ring terminals you create multiple contact areas where current passes through. These areas will go through thermal expansion and contraction with current flow. This will result in your connection loosening over time increasing resistance.

I am curious to my other question if anyone HAS added a positive bus bar off the pos battery post in addition to what Ford has already provided?

Folks that do major audio upgrades do it routinely, my suggestion would be to fuse on each circuit so you're not relying on a mega fuse or heavy circuit breaker to protect a small device. Wires will let out the magic smoke well before blowing. Maybe something like this.

https://www.amazon.com/Circuit-Wate..._r=44D27AMAT0FAFC72FTZD&qid=1714562436&sr=8-6

 

[Tigerbug]

Folks that do major audio upgrades do it routinely, my suggestion would be to fuse on each circuit so you're not relying on a mega fuse or heavy circuit breaker to protect a small device. Wires will let out the magic smoke well before blowing. Maybe something like this.

https://www.amazon.com/Circuit-Waterproof-Indicator-Waterpoof-Automotive/dp/B096Z1WNLW/ref=sr_1_6?content-id=amzn1.sym.3e23f907-b859-4094-8b45-cf96f8c9286b:amzn1.sym.3e23f907-b859-4094-8b45-cf96f8c9286b&dib=eyJ2IjoiMSJ9.3b6ttLil4IxOJHFCQMpnycEOo0gl3t7j9XhjiEsLtIcrlZAMxO7ENZZ58ZGOcbl7sUk7c8fY38T13kRRaA-VFELx8pMaG_QBv2BXesoaHp4u5m4BhXpCDUiEwe136b8fxA8kLy7C41cEaVf3pt_oxdLt2b4XFuD9JYRJkiPxkvM_XkGFhVASzREGnFTYCsBhbklFn1pqAg3AsP98zw_keIMYAuSk95Oh8XSRKWfOyk8.OHomvR9Oy-m3Wkjqw0nC7AcWLeAkEbNYWgSw8k0o1HE&dib_tag=se&keywords=fused+power+distribution+block&pd_rd_r=c29f5e3c-6a80-4e3d-9a46-10a138b51280&pd_rd_w=ZT4Ep&pd_rd_wg=snKXU&pf_rd_p=3e23f907-b859-4094-8b45-cf96f8c9286b&pf_rd_r=44D27AMAT0FAFC72FTZD&qid=1714562436&sr=8-6

Thanks for sending the link. Right now all the various add ons to the pos 12V side of the battery all have their own inline fuses. They have a variety of amps from a low of 5 up to 60 for one of my audio amps. So for now I guess I'll still stack the rings onto the Ford bus bar but space does get tight with the size of the wires/ring connectors. I'll keep looking for the right bus bar if I feel the need to go that route. In the meantime I frequently check that all of these connections are tight to avoid any possible resistance that might occur.

 

[Brian_B]

Ring terminals have pretty good surface area for stacking. Make sure the nut is tight. Electricians usually recommend no more than 2 if you can help it, but that is mostly just due to the fact that the crimps are thicker than the terminal lug and they can have issues stacking if you aren’t careful with it — any air gap at all is bad, they have to be completely flat and flush on the terminal with the nut properly tight.

It also isn’t hard at all to add another terminal strip - they are readily available at auto stores and Amazon. Yes, each wire needs its own fuse or breaker, as close to the battery as you can manage.

 

[ZapMflash]

I added positive and negative bus bars under the fender lip of the driver's side fender. I have a lot of additional connections and this just cleaned it up. They can be found on Amazon.

 

[Tigerbug]

I added positive and negative bus bars under the fender lip of the driver's side fender. I have a lot of additional connections and this just cleaned it up. They can be found on Amazon.

 

[Tigerbug]

What gauge wire from battery to bus bars?

Also do you know what the max length of these wires should be?

I flat tow my Bronco and the area you mounted your bus bars is not available to me as it has an air tank that is used to engage the braking for being towed. I'm going to have to investigate mounting options/locations if I add bus bar (s)

 

[ZapMflash]

I used standard(4 gauge) battery cables 24" long. Unless you're pulling abnormally high amps you can go several feet with that size. You can search Google for cable amperage sizing, it's a fairly simple calculation.

 

[Brian_B]

What gauge wire from battery to bus bars?

Also do you know what the max length of these wires should be?

The length of the run and the total number of amps you want to carry determine the gauge of the wire. Those numbers are whatever you want them to be based on what you are installing and where you are installing it - and yes, @ZapMflash is correct - there are plenty of charts on the internet to help you cross reference the gauge you should be using (try searching for automotive ampacity)

You do not have to size for the max amps of the bus bar or fuse panel or relay box. You can go smaller if you want, and in fact, most do. It’s unusual to have a fuse box where the max sized fuses are installed in every slot and they are all turned on at the same time. Going bigger is always better for electrical, but it is more expensive and is harder to run and makes a bigger boom if it shorts, so trade offs. Size for what you expect to use, plus some margin and some room for future stuff.

That said, you absolutely should fuse the wire based on the gauge you pick, so that the wire itself doesn’t become the fuse. A four foot run of #4, for example, could go up to 200A - so it should have a fuse or breaker that size or smaller to protect it.

The fuse or breaker should be as close to the battery as you can reasonably get it.

And last tip - if you are doing a ground bus - make the ground connection the same gauge as your hot lead. It has to potentially carry the same number of amps. A lot of equipment will ground to chassis locally, but if I were doing a ground bar I wouldn’t assume that and size the cable any smaller than the fuse on the hot lead can protect.

 

[Tigerbug]

All great & helpful information from evryone. Thanks

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