This guide covers the gear that keeps a boat battery safe and connected: battery boxes and trays, isolator and selector switches, switch panels, marine cable, lugs and terminals. Our battery accessories are in stock at our Auckland warehouse and shipped NZ wide, generally next working day.
Quick answer
- Best battery box for larger batteries: Tenob TUFF Large Battery Box, NZ made for 11 to 15 plate batteries.
- Best for tight spaces: Moeller Battery Tray with Hold-Down Bracket, no metal parts to corrode.
- Best battery isolator switch: BEP Battery Switch, isolator and selector versions.
- Best for switching between two batteries: Perko and TMC 2-Battery Selector Switches.
- Best marine battery cable: Tenob TUFF Marine Battery Cable, tinned and multistrand, sold by the metre.
- Best switch panel: BEP Switch Panels, Contour and Splashproof series.
Battery accessories comparison
| Product | Type | Best for | Key facts |
|---|---|---|---|
| Tenob TUFF Large Battery Box | Battery box | 11 to 15 plate batteries | Internal 350 x 185 x 280mm, buckle, strap and two floor cleats included |
| Easterner Battery Box and Strap | Battery box | Popular starting and deep cycle sizes | Medium 265 x 278 x 208mm (H), Large 327 x 178 x 229mm (H), strap included |
| Moeller Battery Tray | Tray with hold-down | Confined spaces | Max battery 260 L x 171 W x 206mm H, no metal parts |
| Easterner Battery Tray | Tray with cross beam | Where a box will not work | 280 or 320mm long, 178mm wide, bottom fixing points |
| BEP Battery Switch | Isolator or selector | Main battery isolation | Easy Fit model surface mounts or fits through a panel up to 19mm, spare 701 Series keys |
| Perko, TMC and Red Key Switches | Isolator or selector | Two battery setups | Red key isolator rated 500 amps intermittent |
| Tenob TUFF Battery Cable | Tinned cable | Battery and starter runs | 3mm² to 95mm², single or twin core |
| Tenob TUFF Cable Lugs | Closed-end lugs | Sealed crimp connections | Tinned copper, 6mm² to 95mm² cable, 5mm to 16mm stud holes |
| Bus Bar | Bus bar | Tidy 12V or 24V wiring | BU905 rated 100A, BU910 rated 150A |
How to choose battery boxes, switches and cable
- Measure the battery first. Compare length, width and height with the box internal size or tray maximum, and allow a little room around it.
- Box or tray. A box contains the battery fully. A tray with a hold-down suits spaces too small for a box.
- Isolator or selector. An isolator simply turns the battery on or off. A selector switches between two batteries.
- Size cable by area. Marine cable is sized by cross-section area in mm², not diameter, and should match the electrical load. Use tinned multistrand cable, which resists the marine environment far better than automotive cable.
- Match lugs to cable and stud. Choose the lug by cable size and by the stud hole on your battery or switch.
Battery boxes and trays
The Tenob TUFF Large Battery Box is made in NZ with extra-heavy moulded plastic to handle knocks on boats and trailers. The Easterner Battery Box comes in medium and large, with different footprints, so check your space as well as your battery. If you need a replacement, the Easterner Hold Down Strap comes with two cleats and four screws and suits small to medium boxes.
Where space is tight, the Moeller tray has an overall size of 283 L x 197 W x 257mm H. The Easterner tray uses a cross beam to secure the battery and fixes down through the base.
Battery switches
The BEP 700 Series comes as the 701B isolator and 701S selector, plus the Easy Fit model. In our isolator and selector range, Perko housings are fibre-reinforced polycarbonate and the Perko selector uses make before break technology, so you can switch batteries with the engine running. It handles 250 amps continuous or 360 amps intermittent. We are the NZ distributor for Perko.
The Osculati Battery Switch has a hinged flap and removable key, and suits disconnecting accessories such as capstans. Contact us for availability.
Switch panels
BEP Switch Panels come in Splashproof 4, 5 and 6-way, and the Contour 6-way. The Contour has green LED backlighting, a red indicator light for each switch and pop-off front covers for easy installation. The fused version includes 3 inline fuse holders.
Cable, lugs and terminals
Tenob TUFF cable runs from 3mm² to 95mm², covering most needs up to large inboard starting. Finish it with closed-end lugs, crimped with a hex or indent tool and sealed with adhesive-lined heat shrink. At the battery post, Projecta brass terminals are sold individually in 8mm or 10mm bolt sizes, while Easterner terminals come as a lead or zinc pair with wingnuts.
Common questions
What size boat battery box do I need?
Measure your battery and compare it with the box’s internal size. Our Tenob TUFF large box is 350 x 185 x 280mm inside and suits 11 to 15 plate batteries.
Which BEP battery switch should I buy?
The 701B is the standard isolator and the 701S is a selector switch of the same size. The Easy Fit model can be surface mounted or fitted through a panel up to 19mm.
What battery cable size do I need for my boat?
It depends on the electrical load. Our tinned cable is sized by area. As a guide, 6mm² is about 10 AWG, 25mm² is 4 AWG, 50mm² is 1 AWG and 95mm² is 3/0 AWG.
Are lead or zinc battery terminals better?
Lead needs relatively little maintenance. Zinc has higher conductivity but needs a little more upkeep. Clean and grease all terminals regularly.
Do you sell boat battery chargers in NZ?
We carry the Quick SBC three-stage charger, with charging regimes for liquid electrolyte, gel and AGM batteries. Contact us for availability.
Need help wiring your batteries? Call us on 0800 273 9180 or visit our Burswood warehouse, Monday to Friday 8:30am to 5pm.
