Which cables to buy?

[dcampbell999]

I want to order 12" cables to hook 2 Valence batteries together. When I went to my local Ace Hardware to figure out if I needed 3/8 or 5/16 lugs I was told the posts were metric M6x1. When I measured the posts with tape measure it looked really close to 3/8". Do the lugs have to fit perfectly? I also want to order cables to go from battery to Gentech inverter. I was told those posts were metric M5x.8. They look a little smaller than the battery posts. Will a cable 3/8 " on one end and 5/16" on the other end work for that? Thought maybe some of you pros may have made these same connections at some point. Thanks for any help.

 

[John Frum]

I want to order 12" cables to hook 2 Valence batteries together. When I went to my local Ace Hardware to figure out if I needed 3/8 or 5/16 lugs I was told the posts were metric M6x1. When I measured the posts with tape measure it looked really close to 3/8". Do the lugs have to fit perfectly? I also want to order cables to go from battery to Gentech inverter. I was told those posts were metric M5x.8. They look a little smaller than the battery posts. Will a cable 3/8 " on one end and 5/16" on the other end work for that? Thought maybe some of you pros may have made these same connections at some point. Thanks for any help.

M10 is nearest metric size to 3/8"
M8 is nearest metric size to 5/16"
M6 is nearest metric size to 1/4"

6mm to inches - Google Search

 

[HRTKD]

I make my own cables. In part, it's an OCD thing but cost, logistics and planning are also factors. Pre-made cables are expensive, they take time to ship and the assumption there is that you know the exact length needed for a connection. You can fudge on the last point by ordering all your cables ~10% longer than you think they need to be. But then you end up with excess cable that can be difficult to arrange/orient.

I ensure that each ring terminal (aka cable lug) is the appropriate size for what it's going on. 3/8" lug for a 3/8" stud. In a pinch, if the terminal hole on the lug is too small, I'll drill out the hole to fit. This isn't easy to do and can be a bit dangerous if you don't secure the terminal. Don't ask how I know this. I don't like having sloppy fittings, meaning that a 3/8" lug on an M6 terminal isn't OK in my system.

Pre-made cables are constructed with the assumption that there won't be a curve near the end. A curve near the end puts some stress on the lug. When I know my cable will curve at the end, I put the curve in the cable before crimping the lug to the cable. That way there isn't any stress on the lug.

I keep a good inventory of cable lugs in various gauges and terminal sizes within each gauge.

 

[Hedges]

I bought these:

4/0 Solar Battery Cables 10" Long Waterproof SEALED WIND/ LOT OF 10 USA | eBay

Lot of 10 Solar Battery Cables 4/0 10" Long Waterproof SEALED Marine USA MADE QTY: 10 CABLES @ 10" 4/0 Gauge Copper Battery Cable Power Wire Auto/Marine/Inverter/RV/Solar CONNECTORS USED: TINNED COPPER CABLE LUGS STUD HOLE:3/8 EACH END IS CRIMPED WITH A HYDRAULIC AIR CRIMPER 6 TON FORCE EACH END...

www.ebay.com

 

[MichaelK]

I just make my own out of copper tubing. I've made as large as 4/0 copper wire connections out of 1/2" copper pipe. I first flare one end to receive the wire, flux the wire, insert it about half-way, then crimp it in place with a Zurn crimping ring. After flattening the other end, I solder the wire in place with acid-free rosin solder. I finally drill a hole in the flattened end to bolt down the connection.

They've worked flawlessly for years now.