A while ago, I think I saw someone describing the use of copper bar or flattened copper tube as a connector for the ground terminals on battery banks. It would seem that that would get away from a lot of connections or overlaps on individual jumper wires, not to mention the savings of a fair amount of $$$ on 4/0 cable. But there are usually benefits or drawbacks on everything.
Any discussion on what you did (or plan to do)? I guess it would be pretty easy to convert 4/0 cable to metric CSA measurements and then re-convert the CSA to inch-measurements for thickness of copper used in this way, but again I'd appreciate info on what you've done.
Thanks, BH NC USA
(Edit - this is a house battery bank, BTW.)
I would probably do this using copper bar stock, not water tube, but as you say do the math and see what the cross-section comparison looks like. Here is an interesting article about connections and solutions in a different type of battery. Dealers are going to be hosing people with a whole new range of shoddy diagnostics soon...
http://www.autoblog.com/2015/02/17/fix-toyota-camry-hybrid-battery-vinegar-baking-soda/ (http://www.autoblog.com/2015/02/17/fix-toyota-camry-hybrid-battery-vinegar-baking-soda/)
Brian
I used battery connectors like this, where the cable passes through rather than terminates, to make-up a single cable that connected all four of my chassis batteries. The cable insulation can be removed and then slipped back on between each connector as well.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.vehicle-wiring-products.eu%2Fshopimages%2Fproducts%2Fextras%2FBT450Pb.JPG&hash=6eb07a2abe3e7bf0f693d7e514859ecd4f9209b0)
I dare say that crimped-on connectors are better - possibly these are even crimp versions of these available, but I didn't bother looking because I don't have a suitable press to do the crimping
Jeremy
I'm now making several busbars for my house system. I'm using 1/4" x 1" C-110 copper that has an ampacity of 400A (for a maximum 30C temperature rise): http://www.copper.org/applications/electrical/busbar/bus_table3.html (http://www.copper.org/applications/electrical/busbar/bus_table3.html) That works out to an even 100A per 1/4" square section, making it easy to calculate what will be needed. Even after drilling 5/16" holes where sections of busbars need to be connected with brass bolts and nuts, that still leaves me 275A ampacity there, more than sufficient for my house system that is designed around a minimum of 250A capacity for all its cables/pass-throughs/switches/etc. Incidentally, this copper is very sticky - the drill bits wants to grab and bind, but I found that using a sulphured cutting oil and very light downfeed on the drillpress works best.
However, I will not be using busbars to connect my house batteries themselves. I've heard stories of this causing the batteries' posts to weaken or even break due to movement or vibration between batteries while driving. For inter-battery connections I'll use 4/0 welding cable and tinned closed-end lugs, with adhesive color-coded heatshrink - this will allow for any slight movement between batteries, and will also permit changing to different makes of batteries that may have slightly different post locations.
I did use some short lengths of flattened copper water pipe to make short connections for my charge controllers. These will only carry a maximum of 60A each, so water pipe is OK for those light loads. Copper water pipe does not have the same electrical properties as C-110, so it's not recommended for heavy loads. There's a good discussion about this exact subject on the Northern Arizona Wind and Sun forum - when I get home I'll try to send you the link to it.
John
Quote from: Iceni John on February 18, 2015, 08:28:31 AM... However, I will not be using busbars to connect my house batteries themselves. I've heard stories of this causing the batteries' posts to weaken or even break due to movement or vibration between batteries while driving. For inter-battery connections I'll use 4/0 welding cable and tinned closed-end lugs, with adhesive color-coded heatshrink - this will allow for any slight movement between batteries, and will also permit changing to different makes of batteries that may have slightly different post locations. ...
Thanks, that's something that I was thinking about and I can't see a good way to avoid this with a solid bus bar. I appreciate that comment, John.
OK Bruce, here's three threads from NAWS about busbars and batteries:
http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/off-grid-solar-battery-systems/6495-battery-interconnections?7629-Battery-interconnections= (http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/off-grid-solar-battery-systems/6495-battery-interconnections?7629-Battery-interconnections=)
http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/general-solar-power-topics/13285-busbar-as-battery-interconnects?14879-Busbar-as-Battery-Interconnects=&highlight=copper+pipe+busbar (http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/general-solar-power-topics/13285-busbar-as-battery-interconnects?14879-Busbar-as-Battery-Interconnects=&highlight=copper+pipe+busbar)
http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/general-solar-power-topics/525-using-copper-pipe-for-busbar?498-Using-copper-pipe-for-busbar= (http://forum.solar-electric.com/forum/solar-electric-power-wind-power-balance-of-system/general-solar-power-topics/525-using-copper-pipe-for-busbar?498-Using-copper-pipe-for-busbar=)
The NAWS forum has lots of good advice and ideas posted on it, well worth a read.
John
Quote from: Iceni John on February 18, 2015, 07:39:15 PMOK Bruce, here's three threads from NAWS about busbars and batteries:
... John
Thanks! That's very interesting -- I've got a few hours of travel this AM but I'll give those a read this evening. Appreciate the help. BH
Bus bars are pretty cheap to just buy. Making one from copper bar stock might cost more than buying one.
www.vtewarehouse.com (http://www.vtewarehouse.com) sells 250 amp bus bars for under $10. They also have 700 amp ones. If you don't trust these cheap ones then you could pay more for a Blue Seas bus bar.
Bruce I think you are talking about someone was using copper pipe to make cable ends?
I did and they are great. I used Copper steam pipe red strip. A bit more than standard water pipe but thicker also. I had a big piece here so just cut a few pieces of 1/2" and some 3/4" flux them heavy on the inside and the stranded wire cable I was using for batteries and inverter. I slipped the wire into the pipe until it met the wire insulation, crimped them a few time each with standard cable crimpers. Then I smashed the pipe together with a hammer on an anvil.sniped the corner and made the ends round. I melted lead into the wire end until full. Let it dry and then drill the proper size hole in it for wherever it was to go. Have checked them and all is good. They work real well and a whole lot cheaper the the store bought ones. I also put shrink wrap over the transition points where they meet the insulation. HTH
Dave5Cs
Buss bars are great for multiple, high amp connections, but not for batteries. As Ooo posted they need to move.
If you use a copper strip buss bolt it (insulated from) a bulkhead and attach all the batt and other leads to it.
Just make sure there is nothing metal loose nearby to come in contact with it!