I know there are some excellent mechanics on here, so I am hoping for some advice.

I thought that I had solved a battery problem by switching over to heavy cable lugs placed on the lead battery connector under a wing nut :


This combo has taken care of me for about a year on two other applications. It worked so well on a previously problematic automotive cable that I went out and stocked up on 40 of the wingnut style clamps because I expected to slowly switch over to it on my other equipment.

But now I'm stymied... I was replacing a few cables on a JCB 1400B backhoe and ran into one of the frustrating problems that remind me that I am a shadetree mechanic, not a real one. The backhoe had never had a starting problem... But I pulled the battery because I was doing a bunch of things to the machine and figured I'd trickle charge it for the week that I had it taken apart. I noticed that the existing cables were pretty small (1/0 I think, although I didn't measure.) The battery clamps were old and nasty.

I took out the old cables, cleaned up the frame contact spot, and then made up some monster heavy cables that are kind of ridiculously overkill. 4/0 cable, and heavy wall lugs hydraulically crimped. The frame contact was shiny... The bolt torqued correctly. The battery was fully charged up, and I performed a CCA test (790/850 CCA- pass.) The cables had been 1/0 with bolted lugs and now changed to 4/0 with hydraulically crimped lugs.

It worked great. For 5 start/stop cycles, cranked quickly. I drove it out into the woods for an important (time deadline approaching) project and worked it for a little bit then shut it off for lunch. When I tried to start it, it had the classic starting system symptoms that indicate a weak battery or tired starter. Put a jump starter on it and it almost started but not quite. Brought a generator out in the woods and charged the battery. The next time I had the jump starter, the boost from the charger and a freshly charged battery. Same thing. I suspected the battery even though it had tested fine because it is 6 years old (because you can't always be sure of the kind of cheap battery clamps that come with modern jump starters and battery chargers. I'm reaching, I know.) Hauled the charger and battery through the woods and back to the shop and the battery still tested fine. wth

I'm going to bring out a clamp on ammeter the next time I head out there just in case the starter is the problem. If it is the starter, that's some coincidence.

So last night as I sat pondering this mystery I Googled "best battery cables" and "make best battery cables" and several other searches along those lines.
I found out that the kind of battery clamp that I had been so happy with (with the wing nut in the photo above) is referred to as a cheap clamp. Ok. That article told me to buy cast copper tin-plated clamps at around $10 to $15 each.
Before I change from lead clamps that seemed to have worked all my life, may I have some ideas from some of you expert mechanic fellows on whether the lead clamps are too cheap for quality repairs?
Using heavy lugs with the wingnut introduces one more "contact" for a tad more resistance, but it worked fine for 5 starts, and for about a year on two other machines.
Any ideas here? I hate shotgunning something like this, especially when it involves working out in the woods away from the shop.

How many volts are you getting to charge your battery did you measure it with a meter?

Somebody found my JCB unattended on our treefarm a few years ago and destroyed my instrument panel so I have no instrumentation as it's being cranked and after running. ($1400 for full replacement, so I plan on building a panel with aftermarket gauges and alarms.)

Fully charged battery at about 12.8 volts, doesn't drop when hooked up in the backhoe. Calibrated Fluke multimeter.

Need to verify the alternator is functioning properly. Possibly it's not charging and the tractor is running off the battery. After running like this for a while the battery won't have the ampacity needed to turn the starter.
I've never had a problem with those stud type post clamps.

Like Ole said, what voltage is your battery charging at?
Kinda sounds like a bad diode in the bridge rectifier.
Measure the charging voltage, the voltage after charging, and the voltage an hour after charging.

I can't count the number of loose "fan belts" I've tightened to fix charging problems when the setup is using V-Belts. The alternator may be turning but if it's under load (charging plus accessory current it's providing) they slip and the output is greatly reduced. Rule of thumb, if you can rotate the alternator by it's fan blades and not have the belt move when the engine rotates slightly, you are too loose. The "poly-V" or flat belts pretty much don't have this problem.

Second, if you suspect a loose connection, after trying to start the engine and it fails to do so, start looking for hot connectors. Careful, they get real hot if they're loose so just touch quickly, don't wrap your hand around them. Connections at the starter stud, solenoid (if a separate one is used) and at the battery. When installing this type of clamp the post and inside of the clamp should be "shiny metal". I used to actually cut all the oxidized lead off the surface of the posts when installing fresh cables or clamps. I never coat the terminals with any "preparation-H", I just make sure to clean the terminals once per year, at least. Oil, Grease, or terminal coating sprays just work their way into the contact surfaces and turn into insulation.

As the others have stated I suspect that you have a charging problem. Now as to your cable ends.....the lead ones are junk. You can either use hydraulic compression or solder on ends and solder the ends on yourself using a propane torch. As to the size of your cable.......I use larger cable then #4. The larger the cable the less resistance. I am using 000 cable on one of my cars that requires a high torque starter.

Once you get a good set of cables made for you rig they will last a lifetime.

I like the Military Style battery terminals myself. Bit pricey at ~10 bucks each but worth it to me.

As for the cable 4/0 is huge and should be perfectly fine. Remember a lot of cars/trucks these days only have 4 gauge! But bigger never hurt anything.

As for your problem...sounds like some sort of charging problem. Id bring the Fluke back out and just start poking around.

The battery was fully charged with the battery charger and generator, plus added Boost and a jump starter.

The cables are 4/0, not #4... What I did with cables is like replacing a 5/8" garden hose with a 2-1/2" fire hose.

The resting voltage of the battery has been checked ( 12.8V . )
CA and CCA have been checked and pass specs. (790 CCA / 850 , and 960 CA / 1000.)

deadshot2, you may be on something. After I tried to start it the last time, I did check the battery posts for warmth, but not the other ends. I should have. The (+) post was warm (not hot) and the (-) post was ambient. I chalked that up to having two ring terminals stacked on top of the heavy lug and the (-) having only the heavy lug. That doesn't make sense in hindsight.

Thanks Lew- glad that it's not likely to be the lead battery clamps with wing nut. Has to be a loose or poor contact somewhere unless the battery has some failure mode that is escaping me. The CA and CCA tests were done with a non-loading tester, #6 on this list.
http://dabestreview.com/top-10-best-car ... y-testers/

I wasn't aware that there was a military style. I'm going to look that up. Thanks.



It's possible that there is a charging problem in addition to my starting problem, but when I am starting out with a fully charged battery it doesn't make a lot of sense to me how the charging system is at fault. See what I am saying?

The tin coated copper is the way to go. They make them in crimp or solder. I would go solder unless you have the crimpers. Batteries plus had them. Solder type are sometimes brass. Also get good glue filled heat shrink to seal the connection. Ill send a pic later of the ones i build.

Military style might not be the right word....more i mean "Mil-Spec" ones. This is the one i used in my dual battery setup (the A52425 is the mil-spec number the 1 is positive 2 is negative)
https://www.amazon.com/Fastronix-Milita ... B005260K2A

Just my preference on terminals though...plenty of other good options.





Ahhh i just reread your post a bit more clearly and see what you mean

Matt, still waiting on the pics.
I crimp with a hydraulic press, the hexagonal dies. The lugs are tin coated copper. The battery post clamp is lead with an embedded 3/8" bolt for attaching lugs. Makes for one extra resistance point over the traditional battery post clamp crimped/soldered to the cable.

Here's a pic of one of the 2 cables I made up for the backhoe. 4/0 cable with a 30-06 for size comparison.

Hm. Something seems odd about that now that I see the pic. Is it really 4/0? Seems kind of small next to that '06.
I'll check it again.

Yesh, it says 4/0.


Hm.
Oh my. Silly me.
Now it is compared to a 30-06. haha


I did make the cable about 6" longer than was required... Shouldn't make any difference with 4/0 cable.
So why'd I make it 6" longer than required?
As I was measuring out the cable I recalled something my wife had said to me recently. "You need 6 more inches" ... Not sure what she meant, but I moved the loppers 6" up the cable and whacked it off.

I did not say that.
I need to start monitoring his internet usage.

Don't get too tangled in your jockeys over wire size. Most runs in vehicles are so short that #4 wire does a fine job. The reason one goes to the larger like #2 or even 0, 00, is to eliminate voltage drop over LOOOONG runs. If the battery is within an arms length of the starter what you showed in your picture will work just fine.