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1.1 Dual Battery System

Vehicle: 2012 Jeep Wrangler JKU, 3.6L (not a Rubicon)

Kit: Genesis Offroad JK Dual Battery Kit, an older generation (earlier than the current Gen 3), with the Genesis smart isolator

Part Number: Not recorded

Install Video: Genesis Offroad installation videos

Charging Between Batteries: Genesis smart isolator only. There is no DC-DC charger. The Nissan NV's Genesis tray pairs with a REDARC BCDC Alpha 50 (NV Batteries & Charging), but the JK does not use one.

Batteries: Two Odyssey AGM Group 34, the same as the Nissan NV

How It Works

The older kit's smart isolator connects the batteries once the cranking battery reaches 13.2 V, so the alternator charges both batteries. It separates them when the cranking battery falls to 12.7 V, which keeps enough charge in the cranking battery to start the engine1.

Accessories on the kit's power and ground bus bars run from the AUX battery1.

Start Boost button: pressing it connects both batteries for 1 minute, like built-in jumper cables. The system then returns to automatic mode1.

Specifications

These figures are for the older kit, from a reseller listing1.

Item Value
Isolator rating Sold with either a standard 85 A or an upgraded 200 A isolator. Which one this JK has is not yet known.
Isolator connect / separate Connects at 13.2 V; separates at 12.7 V (cranking battery)
Inter-battery cable Flexible 2 AWG
Bus bars Power and ground. High-amp loads such as a winch go on the large center post; smaller loads go on the screw terminals.
Batteries Any Group 34
Kit contents Tray, top lid, smart isolator, boost switch, power and ground bus bars, all wiring, fuse box mount, evap solenoid mount and hoses

Current Gen 3 specs do not apply

The current Gen 3 kit (P/N 131-JKDBK2AG3) has a 300 A combiner and an Auto/On/Off boost switch2. This JK has the older kit, so use the 85 A or 200 A rating printed on the installed isolator instead.

Loads

Load Connection State Notes
SwitchPros SP-9100 Direct to the AUX battery posts, not the bus bars Planned Supplied 4 AWG cable with a 125 A in-line fuse. See SwitchPros SP-9100
Power and ground bus bars - Nothing connected (2026-09-24) -

The SP-9100 connects to the AUX battery, not to the isolator, so its load never passes through the isolator.

Outstanding Items

  • Read the isolator's rating (85 A or 200 A) off its label, and record the kit's part number if it is marked
  • Record the exact Odyssey model number and Ah rating of both batteries
  • Record where the Start Boost button is mounted, and confirm it works
  • Identify which physical battery in the tray is AUX, so the SP-9100 lands on the correct posts

  1. Toys For Trucks listing, "JK Dual Battery Kit 200 Amp Isolator 07-11 Wrangler JK Genesis Offroad" (P/N GEN-131-JKDBKE2A-FWMW), https://www.toysfortrucksofficial.com/product/jk_dual_battery_kit_200_amp_isolator_07_11_wrangler_jk_genesis_offroad (accessed 2026-09-24). This is the older, pre-Gen 3 kit in its 2007-2011 fitment. It is the source for the 85 A and 200 A isolator options, the 13.2 V and 12.7 V thresholds, the 1-minute Start Boost, the AUX-side bus bars, the 2 AWG inter-battery cable, and the kit contents. The 2012+ version was not checked separately. ↩↩↩↩

  2. Genesis Offroad, "2007-2018 Jeep Wrangler JK Gen 3 Dual Battery System" product page, SKU 131-JKDBK2AG3, https://www.genesisoffroad.com/products/gen3-jk-dual-battery-kit (accessed 2026-09-24). ↩