This bulletin describes how to correctly maintain the connections on new modular batteries. Connections should be checked with two 5/16" inch wrenches whenever the battery is watered. If the nut loosens the discharge current will not properly travel through the connectors from cell-to-cell. Connections will then smoke, arch and possibly melt. This is especially important in high discharge current applications such as starting.

If it is determine that connections are coming loose we suggest using an 18-8 stainless steel 5/16” Nylock nut. Because the cells are to be removable we do not supply the modular units with this type of nut.

Bolt-Tightening Procedure

The stainless steel bolts will break at a torque of 35 ft-lbs. We recommend the nuts be torqued to 25 ft-lbs. Strongly tightening the bolts with wrenches will get the torque to 25 ft-lbs.

1. Remove the cell-to-cell cable(s). This will stop any cell-to-cell shorts if a wrench slips and forms an electrical path from one side of the battery to the other.
2. Double check each bolt for tightness and re-tighten if necessary.
3. Replace cables and tighten.

Caution: The cell posts are quite close together and it is easy to short the cell by touching both posts with a wrench. Remember you are working around a live lead acid battery and should take all the precautions outline in bulletin 607, Basis Lead Acid Safety Principals.

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