Battery cable question

[FNQCairns]

FNQ,

What did you end up with?

It appears that I will be looking for some as well, the person who had my boat before me put a part of my battery cable through a bulkhead below the floor and the rubber hose he used for insulating slipped off, resulting in the aluminium wearing through the insulating rubber of the cable.

And here was me wondering if I had a voltage leak in the wiring!

Cheers

Geoff

Hi mate I didn't get very far, the ready made ones were too short and I have not bothered to commision someone to make a proper one up for me, I end up using a couple I saved from a twin battery setup in a 4wd before I sold it.

They are only the low grade cable with the compression ends, need to change them before too long.

Sorry no help,

Thanks for all the good replys above I forgot about this post in the meantime, will print it out now to save me asking the same again

cheers fnq

[Handyman]

I bought some of this cable from Whitworths about 18 months ago. Actually bought the cable by the metre with the lugs seperate as I needed more length than the standard.

I must admit I was disappointed at the size of it when it turned up - about 6mm or 1/4", but used it anyway as there was a fishing trip on the next day.

I use it to run my Minn Kota 55 from a relocated deep cycle battery approx 1800mm away. It's still there and the battery /electric motor is still working just as well as it did when the battery was connected via the original 1m cables attached to the motor. No sign yet of voltage drop, battery drain or corrossion of cables/lugs.

Of course is not be the same as starting a decent sized outboard, but it is constant work, often for hours at a time.

[Hamish73]

I checked some specs at work today
16mm2 cable 125 amps continuous 245 amps 20% duty cycle $unsure as we dont stock it
25mm2 CABLE 160amps continuous 330 amps 20% duty cycle $5.50/metre
35mm2 CABLE 205 amps continuous 410 amps 20% duty cycle $9.00/metre

Crimp lugs are about $2each.

[finga]

Gees Hamish those specs are different to the one's us everyday house and industrial sparkies use.
16mm is 83A continuous if surface mounted or 97A if air gapped and seperated.
25mm is 115A and135A respectively
35mm is 135A and160A respectively and thoese numbers are taken from the MM cables little orange book. (referenced to AS3000, 3008)
If you go XLPE in the insulation the current carrying capacity goes up a tad but not up to the figures you quoted.
Where are those figures from??

[plaztix]

I'm struggling with a similar issue at the moment.

I just got a new 50lb Minn Kota transom mount and am keen as to get out and use it but want to wire it up properly before i do, otherwise, well we all know that if its not done properly the first time it wont get done.

I am running an 85Ah deep cycle (firstly is this big enough for half day trips, mainly just to hold ground around structure etc., the 2 stroke does the hard work) and will mount the battery in the middle of the boat so i can run cable to bow and stern for the option of bow or transom mounting.

The distance i am running the cable is about 2m each way (to bow and stern from the battery) into an anderson plug at either end and then connect it to the the 1.4m cable out of the motor.

I've been told that 8B&S should do it but this sounds like it is at its max recommended load when at full throttle. So am thinking about going up a size to 6B&S, which is the biggest size you can use for 50amp anderson plugs. Also driveon (another helpful ausfisher) has informed me that B&S stands for Brown and Sharpe, as BM also said, and there is also B+S which is battery and starter. Just to make things confusing

Anyway, what does everyone think, What size cable should i run?

The more opinions i get the more informed (or is it confused) i get.

Cheers

Mat

[Hamish73]

Finga I got those from the cable manufactrer
Our welding cable is all fine strand 'flex' double insulated, so that may effect it.
Some general electrical specs I had at work were more like what you quoted.

Plaztix I have no idea re BS sizing, but 16mm2 would be sufficient, and 'should' fit into a 50amp anderson plug

[FNQCairns]

Yeah that would be right hamish I remember for the same cross-sectional diameter the number of strands made all the difference.

Hamish are those cables tinned?

[finga]

Finga I got those from the cable manufactrer
Our welding cable is all fine strand 'flex' double insulated, so that may effect it.
Some general electrical specs I had at work were more like what you quoted.

Plaztix I have no idea re BS sizing, but 16mm2 would be sufficient, and 'should' fit into a 50amp anderson plug

yep, absolutely correct there.
I've stuffed up again and looked up the wrong cable
Thanks for letting me know matey

[sea raider]

Now I'm really confused,

Have a look at this site:

http://http://www.narva.com.au/Terminals_26.html

I can get some of the 5802-30BK and 5802-30RD (255 amp, 32 mm2) for around $10 per metre. Would that do the job?

Cheers

Geoff

[Hamish73]

Yeah that would be right hamish I remember for the same cross-sectional diameter the number of strands made all the difference.

Hamish are those cables tinned?

nah mate, bare copper

[sea raider]

Also,

What do you use to crimp the lugs on with?

[Hamish73]

Also,

What do you use to crimp the lugs on with?

The correct tool is ideal (auto electricians etc will have one) , but big hammer and sharp impliment will work if thats all you have. Vise crips are a last resort

[Handyman]

Sea Raider, I filled my lugs with solder and then lightly crimped them. The theory was to keep out salt water and other gunk which I thought might accumulate around the crimped join. I'm no expert though - hope there's no reason this may be overkill and somehow counter-productive.

Plaztix, As I mentioned in an earlier post, I have been running the 2BS cable in a similar situation to what you are considering and have had no problems for 18 months. With regard to battery, I have a 100 ah deep cycle and I t will run my Minn Kota 55 all day for normal intermittent use, especially on the lower speeds, but probably only for two or three hours max with heavy use of top speed (i.e. in heavy current or windy weather)

[plaztix]

Cheers hamish,

i went to the local welding supplies shop and they are sorting me out with some 16mm2 cable. They are cutting it to the required lengths, fitting it with lugs and waterproof heat shrinking it for less than i was paying just for cable originally. its all orange (no red and black) but who gives a toss, once its fitted with anderson plugs its fool proof.

Thanks also handyman, i didn't want to go all the way to 2B&S as its a bit of an overkill for me. One thing that was mentioned to me in my search for info was that you have to be careful when soldering, as if the cable gets hot enough to melt the solder it can burn back through your insulation. Probably not a worry if your running cable a lot bigger than required as it wont get hot enough but something to keep in mind. Dont know if it is true but i know that cable can get pretty hot especially when your drawing around 50amps.

I ended up taking the battery back and upgrading to a 115Ah. they did it no questions and it was only $30 extra.