I'm looking to build a power box like this one:

enter image description here

The battery that I'll use is 12V 35Ah deep cycle battery, which has an initial current of <= 10.5A:

enter image description here

Devices that I plan to connect are:

  1. On 12V Outlet Socket will be connected device of 7A
  2. Two devices on 2 USB ports will draw 3.1A
  3. Flashlights will draw 1A
  4. A device on 2-Way Banana Plug will draw about 10A

Total of 21A.

Do that mean that I cannot connect all devices at the same time on this battery because of the initial current of 10.5A?

  • 3
    \$\begingroup\$ i think that rating refers to charge current ... consult the datasheet \$\endgroup\$
    – jsotola
    Jun 4 '20 at 6:01
  • \$\begingroup\$ The rules for use are determined by the battery you use inside the box, \$\endgroup\$
    – Jasen
    Jun 4 '20 at 7:55

The 'initial current' mentioned is not related to its load. It is the maximum permissible charging current when a charger is first connected.

35AH would be the C10 rating (continuous 3.5A for 10 hours).

Going by the specifications for similar batteries, the C5 rating would be 30AH, C3 25AH, C2 24AH & C1 20AH.

The number of charge/discharge cycles over the life span of a deep cycle battery would be 150-200 cycles at a depth of discharge of 100%, 400-500 cycles at 50% and 1000 or more cycles at 30%.

Reference: https://batteryuniversity.com/learn/article/lead_based_batteries

This battery may be used with those loads staggered and with low duty cycles.

  • \$\begingroup\$ I would not assume that 35Ah is the C10 rating. It might very well be C20. \$\endgroup\$
    – StarCat
    Jun 4 '20 at 14:10

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