I'm replacing the cole hersee battery isolating solenoid because it's been working intermittently. The replacement is the exact part except the studs are about 1/8 shorter, and I can't fit all three of the lugs on the stud with room enough to screw the nut on top of them to hold them down.I'm thinking I need to buy a heavy duty bus bar in order to get these connected, but I don't know what size. Since the starter battery delivers 975 cca do I need a $130 1000 amp bus bar? Or am I going down the wrong track?

What I would do is just get a short #1AWG and bolt (really tight!)all four lugs together, then put the #1's other lug on the solenoid. Wrap the bolt and four lugs in tape for insulation.Of course everyone will be appalled and want you to spend the $130 :)

BFL13 wrote:What I would do is just get a short #1AWG and bolt (really tight!)all four lugs together, then put the #1's other lug on the solenoid. Wrap the bolt and four lugs in tape for insulation.Of course everyone will be appalled and want you to spend the $130 :)Not at all, Macgyver. That's simple and brilliant. :C

Another option is to get a short length of copper water pipe, flatten it in a vice, and drill suitably.The bus bar or whatever simply needs to be sufficient for the current flowing through it, not for the theoretical rating of the starting battery. At least in my RV that would be determined by the master fuses at either end of the solenoid, or something like 175A if I recall. Failing that, the wire sizes give some clues as to what to expect.

BFL13 wrote:What I would do is just get a short #1AWG and bolt (really tight!)all four lugs together, then put the #1's other lug on the solenoid. Wrap the bolt and four lugs in tape for insulation. Of course everyone will be appalled and want you to spend the $130 :)Great recommendation. I have done this and it works great but over time encountered a bit of corrosion where the wires are grouped together. Still a good solution.

Depending on the size of the lug.... There is a product you can get at a battery store that is a bolt/nut.. Basically it's a lug extenderIt may have long enough threads or you can put one lug under the extender and tighten it down then put the other 2 on it (or the other way around)

Not enough space for lugs on post of battery isolator

4aSong
Explorer
Jan 27, 2020
BFL13 wrote:
What I would do is just get a short #1AWG and bolt (really tight!)all four lugs together, then put the #1's other lug on the solenoid. Wrap the bolt and four lugs in tape for insulation.

Of course everyone will be appalled and want you to spend the $130 :)

Great recommendation. I have done this and it works great but over time encountered a bit of corrosion where the wires are grouped together. Still a good solution.
DrewE
Explorer II
Jan 27, 2020
Another option is to get a short length of copper water pipe, flatten it in a vice, and drill suitably.

The bus bar or whatever simply needs to be sufficient for the current flowing through it, not for the theoretical rating of the starting battery. At least in my RV that would be determined by the master fuses at either end of the solenoid, or something like 175A if I recall. Failing that, the wire sizes give some clues as to what to expect.
MDKMDK
Explorer
Jan 27, 2020
BFL13 wrote:
What I would do is just get a short #1AWG and bolt (really tight!)all four lugs together, then put the #1's other lug on the solenoid. Wrap the bolt and four lugs in tape for insulation.

Of course everyone will be appalled and want you to spend the $130 :)

Not at all, Macgyver. That's simple and brilliant. :C
BFL13
Explorer II
Jan 27, 2020
What I would do is just get a short #1AWG and bolt (really tight!)all four lugs together, then put the #1's other lug on the solenoid. Wrap the bolt and four lugs in tape for insulation.

Of course everyone will be appalled and want you to spend the $130 :)

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Not enough space for lugs on post of battery isolator

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