Combine House bank

Roc · October 26, 2009, 04:40:38 AM

I recently installed 4 golf cart batteries. They are still wired separately (i.e. Battery #1 and Battery #2, like the original 4D's). I'm installing a 'reserve' battery on position #2, so I now want to combine the golf carts into one whole house bank. I don't know if either way matters, but I figured I would thow this out if anyone sees any difference (pro or con) with either way. I can combine them by connecting the two positive poles with a short red wire, then lead one existing red wire to the #1 stud on the battery switch. I then could remove the second existing wire from the run and use that for the reserve battery leading to the #2 stud. The other way would be to simply take the wires, at the battery switch, and connect them both to the #1 stud on the battery switch, This would have both batteries connected 'at the battery switch stud' in lieu of them connected at the batteries themselves, and would have (2) wires leading to the battery switch insead of just one. Any thoughts?

Thanks!

Ken Juul · October 26, 2009, 04:57:08 AM

there is not alot of room or stud length on the battery switch. I suggest you combine your batteries in the battery box and only run one wire to the switch. Re using the cable off the #2 position may or may not be an option. It depends where you place the new reserve battery. The fewer connections the better.

Stu Jackson · October 26, 2009, 08:07:00 AM

There's a third alternative: abandon the second wire and use a new one for the reserve bank since it'll be in a different location and the existing wire is 20 years old with ?-ble crimps.

But it really doesn't matter, as far as current carrying capacity. The OEM #4 red wires are more than adequate to carry the way less than 30 A you'd ever use on the DC load side. Your boat, your choice, just document it properly for the next guy or for you for next season! You may remember my self powered woofer wiring story.

Ron Hill · October 26, 2009, 03:03:45 PM

Roc : You can get an "extension" for the battery selector switch if you want to connect there.

However, I'd do as Stu suggested and combine the golf carts in the battery compartment. Then you can use that "extra" positive wire (alreadt there) for the new single battery if you want to locate it in the battery compartment.

A thought

Roc · October 27, 2009, 04:24:28 AM

Ron,
Good point about combining at the battery...however, where have you seen an 'extention'. Do you mean to extend the threads on the stud?

Thanks!

Ken Juul · October 27, 2009, 10:13:51 AM

depending on the length of you connectors and the thickness of your cable ends here are a couple different ways you can connect the your batteries. Applies to both pos and neg, only one side shown.

Ron Hill · October 27, 2009, 03:22:17 PM

Roc : I found an "extender" in an auto part store (may have been Auto Zone?). It has a female thread on one end and a male thread on the other end - about 2 " long. Look by the batteries. Hope this helps.

canuck · October 28, 2009, 05:12:57 PM

Hi Roc, i am looking to replace my 6 year old Exides and would like to know what brand you installed. Did they fit into the existing space and did you have any height issues?
Anybody with a MKII do anything similar?
Thanks
Latitudes #1678

John Langford · October 28, 2009, 09:24:26 PM

See the following for advice re lengthening the MkII battery boxes to accommodate 4 Trojan T105s or any other golf cart batteries: http://c34.org/bbs/index.php/topic,5188.0.html

There are no height issues

Roc · October 29, 2009, 04:30:39 AM

I could have extended the existing battery boxes, but I found it was easier to take them out and I used 4 group 24 battery boxes instead (golf carts fit inside each one of them). I screwed each one down in a 2 x 2 arrangement. I did need to move the water heater outboard about an inch and cut way at the plywood that the water heater sits on along that edge to give the batteries more room in the length. Width and height are not an issue.

Roc · November 18, 2009, 07:15:02 AM

Another question I have.. When combining the batteries to create the 'House Bank', has anyone put a 100 amp fuse between the two positive connections?

Thanks for your help!

Stu Jackson · November 18, 2009, 09:18:00 AM

Roc, not that I know of. In fact, remember that the fusing is a "newer" ABYC recommendation, so that our earlier boats did not have fused batteries at all. I ran my boat without fuses for the banks until I started installing modern chargers, inverters and the high output alternator. One could go crazy with fusing, but I'd stay with fusing just the banks, not the individual batteries.