I'm sorry, but it is clear that you have no idea what you are writing
about. The 2 batteries are connected in parallel when a relay or
separator is used. The alternator charging current to the aux battery in
no way passes through the primary battery. No matter how discharged, the
aux battery will not draw more charging current than the alternator can
supply, and none of it need go through the primary battery first. In
addition the 1315 separator senses the voltage on both batteries and if
the aux battery is pulling more current than the charging system can
supply and still keep the voltage correct on the primary battery, it
will disconnect the aux battery from the charging system.

Mark

TC wrote:

>>A-the battery must always be recharged at the proper voltage as spec'd by
>>mfg   it must be maintained at FULL charge at all times.
>>B-under/over charge will damage a battery
>>C-a batteries current demand(amps) is directly related to is discharge
>>
>>
>level
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>>2) Each batt gets it volts/amps directly from the alternator
>>    -the aux battery current demand (amps) is supplied from the alternator
>>     not from the alternator AND the 1st battery
>>     in heavy discharge state the aux may not  get the required amps/volts
>>it needs for recharge
>>
>>
>Sorry but I was reflecting on these comment & realized I forgot another
>point
>if the Aux battery is in the heavy discharge state
>it will pull the higher amperage that will pass through the
>primary battery leading to possible over charge conditions on the primary
>
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