Table of Contents
Advertisement
TPD 1399E
Chapter 7
Starter battery
The performance of starter batteries is commonly
expressed by the current in amperes that they will
supply under specified conditions.
A suitable battery for the M65 and M85T, if specified
by BS3911, will supply a minimum current of 340A (for
60 seconds, with the voltage not falling below 8.4v, at
minus 18
C).
O
A similar battery, specified by SAE J537, will supply
a minimum current of 540A (for 30 seconds, with the
voltage not falling below 7.2v at minus 18
C).
O
If auxiliary loads are considerable, an additional
battery should be fitted, with a split charge relay as
shown on page 22. This will ensure that the engine
starting battery is kept in a good state of charge at all
times.
Starter cables
The total resistance of the two leads from the battery
to the engine should not exceed 0.0017 ohms. In
practice, this means that the total length of the starter
cables (positive and negative) should not exceed 6
metres if the commonly available 61/.044 cable is
used. Longer cable runs, which should be avoided if
possible, will require either double cables or a heavier
cable, in order to comply with the total resistance of
0.0017 ohms.
Mounting the batteries close to the starter is very
much the preferred option.
Grounding the battery negative
It is recommended that the battery negative busbar
should be grounded as close as possible to the
battery, by a substantial connection to the bonding
system within the boat. This will reduce the likelihood
of interference between items of electrical and
electronic equipment fitted to the boat.
Page 29
Hide quick links:
Advertisement
Table of Contents
