Wire sizes and Fusing

[B and C]

We need to know exactly which batteries you have and what charger you are using. I have 12v AGM batteries (2-125ah) connected in parallel (+ to + and - to -) and have never heard gurgling from them. Hearing gurgling means you have the wrong charger connected to them or the batteries are not AGM. If these are 6 volt batteries connected in parallel and you are charging with a 12v charger, gurgling would occur. You are connecting the charger the correct way.

The 19 inch 4 ga cable is is good. Most people undersize the cables.

 

[dolomiti]

We need to know exactly which batteries you have and what charger you are using.  I have 12v AGM batteries (2-125ah) connected in parallel (+ to + and - to -) and have never heard gurgling from them.  Hearing gurgling means you have the wrong charger connected to them or the batteries are not AGM.  If these are 6 volt batteries connected in parallel and you are charging with a 12v charger, gurgling would occur.  You are connecting the charger the correct way.

The 19 inch 4 ga cable is is good.  Most people undersize the cables.

Actually, the batteries are 100ah, 12v WindyNation and the charger is a Schumacher speed/charge 1.5a.  The charger worked fine on the batteries when they were not in parallel.  

 

[B and C]

[font=Verdana, Arial, sans-serif]dolomiti wrote:[/font]
[font=Verdana, Arial, sans-serif]Actually, the batteries are 100ah, 12v [/font][font=Verdana, Arial, sans-serif]WindyNation[/font][font=Verdana, Arial, sans-serif] and the charger is a [/font][font=Verdana, Arial, sans-serif]Schumacher[/font][font=Verdana, Arial, sans-serif] speed/charge 1.5a.  The charger worked fine on the batteries when they were not in parallel.[/font]

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Just make sure that the batteries are wired in parallel, [font=Verdana, Arial, sans-serif](one cable + to + and one cable - to -).  Disconnect any other cables.  If you have them wired up in series (maintainer to + battery, - cable to + battery, - to maintainer) they will be at 24v.  [/font]

[font=Verdana, Arial, sans-serif]Do you have a meter to check the voltage where you are trying to connect the charger?  If it worked fine when charging individually, see the sentence above.  Wire the negative post to the negative post and the positive post to the positive post.  Your meter should read 12+ volts (not 24 volts) without the maintainer connected unless the battery is really dead.  Put the meter on the posts you were trying to charge from.  Connect the maintainer and read the voltage again.  Should be something like 13.2 to 13.8 volts with it plugged in.[/font]

[font=Verdana, Arial, sans-serif]The "battery charger" you pointed to is actually just a maintainer (for when a battery is not going to be used for awhile) or a really slow trickle charger.  "Schumacher Electric 1.5-Amp Battery Maintainer" is it says in the description.  That maintainer should not be able to boil those batteries.  I have a 30 amp charger and 30 amp solar charger connected to mine and they have never been discharged below 80%.  I have a Trimetric battery monitor connected to mine to see how many amps are going in and coming out.  The most it has ever drawn is 14 amps when charging.[/font]

 

[dolomiti]

[font=Verdana, Arial, sans-serif]dolomiti wrote:[/font]
[font=Verdana, Arial, sans-serif]Actually, the batteries are 100ah, 12v [/font][font=Verdana, Arial, sans-serif]WindyNation[/font][font=Verdana, Arial, sans-serif] and the charger is a [/font][font=Verdana, Arial, sans-serif]Schumacher[/font][font=Verdana, Arial, sans-serif] speed/charge 1.5a.  The charger worked fine on the batteries when they were not in parallel.[/font]

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Just make sure that the batteries are wired in parallel, [font=Verdana, Arial, sans-serif](one cable + to + and one cable - to -).  Disconnect any other cables.  If you have them wired up in series (maintainer to + battery, - cable to + battery, - to maintainer) they will be at 24v.  [/font]

[font=Verdana, Arial, sans-serif]Do you have a meter to check the voltage where you are trying to connect the charger?  If it worked fine when charging individually, see the sentence above.  Wire the negative post to the negative post and the positive post to the positive post.  Your meter should read 12+ volts (not 24 volts) without the maintainer connected unless the battery is really dead.  Put the meter on the posts you were trying to charge from.  Connect the maintainer and read the voltage again.  Should be something like 13.2 to 13.8 volts with it plugged in.[/font]

[font=Verdana, Arial, sans-serif]The "battery charger" you pointed to is actually just a maintainer (for when a battery is not going to be used for awhile) or a really slow trickle charger.  "Schumacher Electric 1.5-Amp Battery Maintainer" is it says in the description.  That maintainer should not be able to boil those batteries.  I have a 30 amp charger and 30 amp solar charger connected to mine and they have never been discharged below 80%.  I have a Trimetric battery monitor connected to mine to see how many amps are going in and coming out.  The most it has ever drawn is 14 amps when charging.[/font]

I definitely had it connected in parallel as, I could see it visually and voltages remain consistent across the parallel and the individual batteries (out of parallel connection) at about 13v.  I think that I did not tighten the leads enough.  I did that this morning and all went well.  Thanks for the help!!! 

 

[Sonyatech]

It is hard for me to pick out exactly what size wiring I should purchase after reading all the posts to this thread. I am building out a Ford E150 and already have one battery, one solar panel, a solar controller and an inverter/charger. My first step is getting the battery isolator hooked up....but after that I can’t decide. I have a whynter fridge, 2 12v fans and 5 devices to charge plus my laptop. I plan on getting another battery and one more solar panel but not right away. So....can I just use all 10 gauge? What about fuses? I already have 20ft of wire for the solar panel. 
Suggestions?
Thanks bunches in advance for any and all help.

 

[akrvbob]

No, you have many different devices with different power draws and lengths. I'd suggest you take each one individually and post it here with the details and we'll help you.

But, what we will all do is take the information you give us and plug it into a cable calculator which will tell us the size.

If you google "cable gauge calculator" you'll find many and you can use whichever one you like. Many of us like the one on the Blue Seas website.

Some of the terminology is tricky, if so post here and we'll walk you though it.

 

[JohnnyK]

Preparing for stage 1 of our electrical upgrades. I'll be replacing the single deep cycle 12v battery that came from the dealer with 4 - 6v Interstate 105 (made by Trojan) and adding a 1500 w inverter. Where and what size should I fuse it at? It will be wired in Series/Parallel to achieve 12v and 220ah. Batteries will be clustered so series cable will less than 1 ft. Parallel cables should be under 4 ft. Inverter calls for 2 awg. What gauge would be good for the other runs? I will also be adding a battery monitor. 

Solar addition is in the future. Likely to be between 600-900 watts. 

Thanks for any help you folks can provide.

 

[Weight]

Are you sure the inverter calls for 2awg. That seems small. As far as the battery connections. Keep all the negative cables the same length, and all the positive cables the same length. It is good practice to use negative and positive bus bars. My recommendation is to use the largest cables you can for the battery inter-connections. 2/0 is fairly easy to use and can be ordered custom made from various suppliers. I use; http://www.genuinedealz.com/custom-cables/custom-battery-cable-assembly (or) https://baymarinesupply.com/wiring/custom-battery-cables.html

 

[JohnnyK]

Are you sure the inverter calls for 2awg. That seems small. 

Yes that is what it calls for, but it seemed small to me also, so I'll likely upsize it to 1awg or 0/1. I was leaning toward 2/0 for the battery connections, so thanks for confirming that. I'll make all of my own custom cables, but appreciate to supplier link. Still unclear as to fusing. (Where, size, and wondering if I could use breakers instead.) Battery cables will go to lugs for distribution. Thanks for the info.

 

[Suprasoup]

1500w/12v= 125a

Use the critical load tables as you want to minimize voltage drop to under 3%. 1awg would be fine for your application.  

https://www.bluesea.com/support/art...oosing_the_Correct_Wire_Size_for_a_DC_Circuit

For fuse sizing use this:

https://www.bluesea.com/support/art..._Fuse_Holder_For_Your_DC_Product_Installation

Your batteries are wired 2s2p which should give you 12v @440AH.

 

[Suprasoup]

Yes that is what it calls for, but it seemed small to me also, so I'll likely upsize it to 1awg or 0/1. I was leaning toward 2/0 for the battery connections, so thanks for confirming that. I'll make all of my own custom cables, but appreciate to supplier link. Still unclear as to fusing. (Where, size, and wondering if I could use breakers instead.) Battery cables will go to lugs for distribution. Thanks for the info.

Fusing should be done at the battery positive terminals.  So in your case you’ll need 2.  1 for each battery string.  Breakers, while convenient, are mechanical devices and can fail. 

Unless you are a sparky you should have your cables premade.  120a is a lot of current.  A failed crimp

 

[Weight]

I like these for the battery positive catastrophic fuse. I have 6 GC2 batteries with three sets of 12 volts going individually to a buss bar. So for me three fuses, one at each 3 battery positives. https://shop.marinehowto.com/products/blue-sea-marine-rated-battery-fuse
I take my other draws from the bus bar with appropriate fuses. The same MRFB as linked.

 

[John61CT]

Just be careful to avoid heavy stresses at battery posts, mount wires for strain relief.

ANL and Class T types are also excellent, and can be mounted a few inches away from batts if your box design allows for that.

 

[BobW55]

Most interesting post.
I am about to install a 12 volt solar system. 3 x 100 Watt panels.
I will be using a single deep cycle battery and an MPPT controller.
Finding 8 gauge or heavier wire is not to easy. But I do have more than enough 10 Gauge.
My 750 Watt inverter has it's own 8 gauge wires on it already, and will only be about 4' from the battery.
I will only be running LED lights and a Lipo battery charger that tops out at 15 amps.

I was going to double up the 10 gauge to run to my fuse/buss block, which may be about 6-8' from the battery.
Question is:
Is it better to run each 10 gauge run into it's own crimped ring, or would you just use one large enough to hold both strands together?

 

[Weight]

Not good to double wire as one wire will always have different resistance and carry more current than the other. You can find quality wire at most Marine Supply retailers such as West Marine. I use genuine dealz for custom cables, fast turn around. http://www.genuinedealz.com/custom-cables/custom-battery-cable-assembly

 

[highdesertranger]

where are you located that you have a hard time finding wire? order it online. highdesertranger

 

[BobW55]

I am in Michigan, about 3 hours North of Detroit.
Closest Marine place is about and hour away. The run from the battery to the fuse block is only 5-6 feet.
Will check at a local auto supply place. See if they have some ready made starter cables, or may just relocate the fuse block.

 

[John61CT]

Genuinedealz.com is an excellent solution, just spec the length very carefully, add some slack.

 

[Weight]

The auto parts store will have battery or jumper cables. But I think it is well worth the time to drive to marine store.

 

[highdesertranger]

most battery cables and jumper cables are inferior to good wire. highdesertranger