Boat lithium upgrade kit, small (single house bank)

Description

Everything that goes around a single lithium house bank on a 12V boat: main fuse holder, switch, battery monitor, two busbars, a 12-circuit fuse block and the lugs.

For a boat with one lithium house battery, charged at the dock or by solar. Bring your own battery or add one from the list below. Example, our math: a 100 Ah lithium battery used to 80% gives 80 Ah, about 20 hours of a fish finder, plotter and LED lights drawing 4 A together.

Add all parts to cart. Already own a part? Set it to 0 below.

What’s in the box

Swaps on this page: Victron BMV-712 Smart battery monitor, black. Set the part you don’t need to 0 and the swap to 1.

Add a battery (optional): Pro-Guide 31M180-DP 12V 180Ah Dual Purpose Lithium Battery; Pro-Guide 24M100 12V 100Ah Group 24 Lithium Battery. Set the one you want to 1. Check its manual for charge voltages and the main fuse it calls for: the class T holder here takes 225 to 400A fuses.

Not in the box

• The battery, unless you add one above
• A charger with a lithium setting (shore or solar), if yours doesn’t have one
• Battery cable (cut it to your boat’s lengths)
• Fuses: the class T fuse, the ANL fuse and the blade fuses. Size each one to the cable it protects and to your battery maker’s spec
• Lugs with a 5/16 inch hole for the busbar studs

Who it’s for

Boat owners swapping one lead-acid house battery for lithium who charge from shore power or solar and don’t need alternator charging into the house bank. It’s the parts list for diagram 1 in our wiring guide.

Good fit if: You’re moving one boat house battery to lithium and you charge it from shore power or solar, not the engine alternator.

Not the pick if: Your engine alternator charges the house bank: get the large boat lithium upgrade kit, which adds a DC-DC charger.

How it goes together

You can do this. Here’s how.

1. Turn everything off and disconnect the battery, negative first.
2. Mount the class T holder as close to the battery positive as it fits. Battery positive to the fuse, fuse to the switch.
3. Switch to the positive busbar.
4. From the positive busbar, the ANL holder feeds the 12-circuit fuse block. Fuse it for that cable.
5. One circuit per blade fuse. Run the small negatives to the fuse block’s ground bar, then one wire from the ground bar to the negative busbar.
6. Battery negative goes to BATTERY MINUS on the shunt. Nothing else goes there.
7. Run one cable from SYSTEM MINUS on the shunt to the negative busbar. Every other negative lands on that busbar.
8. Connect the shunt’s thin fused red wire to the battery positive. That’s how it reads voltage.
9. Fit the fuses, reconnect the battery (positive first, negative last), and set the SmartShunt and your charger to your battery maker’s numbers in the apps.

Read next: Boat lithium battery wiring diagram · Upgrading a boat to lithium

Fit rules

• If the engine alternator charges this battery, this kit is the wrong one. Use the large kit, which adds a DC-DC charger. (Guide 1)
• Main fuse first, as close to the battery positive as you can fit it, then the switch. Many lithium makers name a class T fuse there. Check yours. (Guide 1)
• The Egis 3912 holder takes only 225 to 400A class T fuses. If your battery maker calls for 200A or less, you need a smaller holder (not in this kit).
• The XD switch is rated 225A continuous on one 2/0 cable, 300A on 4/0, and 500A only with two 4/0 cables (Egis XD Series brochure). Rate it by the cable on it.
• Only the battery negative goes on the battery side of the SmartShunt. Every other negative lands on the negative busbar on the system side (Victron SmartShunt manual).
• The Victron busbar has 5/16 inch (8 mm) studs and a 70V DC limit (Victron busbar datasheet). The 2/0 lugs in the kit are 3/8 inch, for the battery, shunt and switch.

Maker’s pages: Victron SmartShunt · Egis class T holder · Egis XD switch · Egis 12-circuit fuse block

Questions

Does this kit include a battery?

No. Use your own and follow its manual for charge settings and the main fuse.

Can I swap the SmartShunt for a monitor with a screen?

Yes. The BMV-712 is listed on this page. Set the SmartShunt to 0 and the BMV-712 to 1 before you add to cart.

Why isn’t there an alternator charger in this kit?

This one is for boats that charge from shore or solar. If the engine needs to charge the lithium bank, pick the large kit, which adds a DC-DC charger.

Why are fuses and cable not included?

Their sizes depend on your cable lengths and your battery. Getting those wrong is the most common lithium mistake, so we leave them to your measurements and your battery maker’s spec.

Each part ships from the maker’s distributor, so a kit can arrive in more than one box.