## How Battery Capacity for Cranking Amperes Combines In Parallel

Electrical and electronic topics for small boats
MATTANZA II
Posts: 2
Joined: Thu Dec 27, 2018 9:23 pm

### How Battery Capacity for Cranking Amperes Combines In Parallel

If I have two [identical] batteries with [a rating of] 550-Ampere [of current at a particular temperature and duration known as "cold cranking Amperes], and they are [connected] to a [common OFF-1-BOTH-2] battery switch, and [the battery switch] is set to [BOTH], will they produce 1,100-Amperes?

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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### Re: How Battery Capacity for Cranking Amperes Combines In Parallel

In the proposed arrangement (of two batteries connected in parallel by the BOTH position of the battery switch) each battery will produce the same current it would by itself. This ability of a battery to supply current really does not change because it is connected in parallel with another battery. Assuming each battery can produce 550-Amperes, then when two are combined in parallel they could, together, produces 1,100-Amperes, as long as the batteries are truly identical. And, of course, the batteries have to be at full-charge and in as-new condition to meet their rated peak current capacity