Wire size please

[Cbprov]

Hi installing a garmin 8622 and a 1222xsv to a dedicated 140ah lithium ,could anybody tell me wire size I would need thank u

[MichAngler]

All depends on location of battery and graphs

If the battery is in the back with the rest of the batteries and one or more graphs are at the bow you want to run 8 or 6 awg to a fuse block under the dash and 10awg from the fuse block to the graphs
You also might want a cutoff switch between the battery and fuse block

If the battery is in a compartment up front you can run 10awg from battery to both graphs
make sure to include a fuse on each

One note not all wire is the same you want pure copper not copper clad and tinned is always best in a marine environment

Last every size wire comes in several classes with different numbers/size strands

Example 10AWG comes in 3 options
37/26 – 37 strands of 26 gauge wire
49/27 – 49 strands of 27 gauge wire
105/30 – that’s 105 strands of 30 gauge wire – this is also called Hook Up Wire used by the high end auto sound system techs and is tinned

The smaller the strands the less resistance/voltage drop so in this case you want the 105/30

[lpugh]

^^^^^^ plus 1

[mikeky]

All depends on location of battery and graphs

If the battery is in the back with the rest of the batteries and one or more graphs are at the bow you want to run 8 or 6 awg to a fuse block under the dash and 10awg from the fuse block to the graphs
You also might want a cutoff switch between the battery and fuse block

If the battery is in a compartment up front you can run 10awg from battery to both graphs
make sure to include a fuse on each

One note not all wire is the same you want pure copper not copper clad and tinned is always best in a marine environment

Last every size wire comes in several classes with different numbers/size strands

Example 10AWG comes in 3 options
37/26 – 37 strands of 26 gauge wire
49/27 – 49 strands of 27 gauge wire
105/30 – that’s 105 strands of 30 gauge wire – this is also called Hook Up Wire used by the high end auto sound system techs and is tinned

The smaller the strands the less resistance/voltage drop so in this case you want the 105/30

Also, the 6ga or 8ga wire will need a fuse or breaker at the battery.

[Cbprov]

Thanks guys

[justinp61]

Hi installing a garmin 8622 and a 1222xsv to a dedicated 140ah lithium ,could anybody tell me wire size I would need thank u

How far from the units to the battery?

[Cbprov]

20ft

[yupitsme]

20ft

DC - double that distance 40'.

[justinp61]

20ft

Doing a little digging we find that those units will draw a maximum of 7.9 amps together. Using one of the many online DC ampacity wire charts we also find that for 10 amps and a 40' run will need an 8awg wire. Google is your friend.

[leo13]

The wire sizing is based on an efficiency rating not the wires actual capacity. For instance for that load 16ga wire would be adequate but just have a higher voltage drop. 8ga is bit on the large size and 10ga would probably be more than adequate for 8amps.

[justinp61]

The wire sizing is based on an efficiency rating not the wires actual capacity. For instance for that load 16ga wire would be adequate but just have a higher voltage drop. 8ga is bit on the large size and 10ga would probably be more than adequate for 8amps.

I agree. When I ran 8 amps on one of the online calculators it came up 10 gauge. For 10 amps it calculated 8 gauge. All of the charts I looked at were in 5 amp increments.

[CJ1]

You also have a bit higher voltage with the LI battery and little to no loss as the battery is used. I run 10 gauge for most electronics with no issues as of yet. May need to go larger as more and more stuff is added. CJ

[bobcoy]

Maybe because I am old, but I don’t want to upgrade down the road. The price difference between 8 and 10 AWG is not that big a deal. JMO Bob