BigBattery ETHOS Parallel Kit Includes:
- 2 × Ethos Parallel Power Cable 4.9 ft (1500mm)
- 1 × Ethos Parallel Comm Cable 4.9 ft (1500mm)
- 1 × ETHOS Rack Base
BigBattery ETHOS Parallel Kit — Multi-Battery Connection Hardware
Parallel-Ready Connectivity for Your ETHOS Battery Bank
- FREE System Design Consultation -- Engineers size your system for your actual consumption
- FREE Shipping -- Ships free — no surprise freight charges
- Compatibility Guarantee -- Pre-vetted to work with ETHOS batteries
$254.95
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In the box
- 2 × Ethos Parallel Power Cable 4.9 ft
- 1 × Ethos Parallel Comm Cable 4.9 ft
- 1 × ETHOS Rack Base
Parallel-Ready Connectivity for Your ETHOS Battery Bank
Scale your off-grid battery bank with the BigBattery ETHOS Parallel Kit. This kit includes everything needed to connect multiple ETHOS batteries in parallel — two 4.9 ft power cables for current transfer between units, one 4.9 ft communication cable so the BMS systems stay synchronized, and a rack base to keep the stack secure. It's a field-tested approach to building a grid-independent power system without guessing at wire gauges or communication protocols. Ships free.
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Parallel Power Link
BMS Comm Cable
Rack Base Included
Ships Free
4
Pieces Included
4.9 ft
Cable Length
1
Rack Base
Parallel Expansion Without the Guesswork
Buying random cables off a marketplace and hoping your batteries talk to each other is how you end up with a silent BMS and a dead bank at 2 AM. The BigBattery ETHOS Parallel Kit eliminates that risk. Every cable and connector in this kit is engineered specifically for ETHOS parallel configurations — the power cables carry the correct current, the comm cable enables battery-to-battery BMS communication, and the rack base provides a stable foundation. At Off Grid Vault, we only carry kits we would install on our own cabins. This parallel kit is pre-vetted for ETHOS compatibility, so you connect your batteries, confirm communication, and move on. No engineering degree required — we already did that work.
BMS Communication Keeps Your Bank Balanced
When you parallel lithium batteries, BMS communication is not optional — it is what keeps your cells charging and discharging at the same rate. Without it, one battery hogs the load while another sits undercharged, accelerating degradation and reducing your usable capacity. The ETHOS Parallel Comm Cable included in this kit links the BMS of each parallel battery so they operate as a single coordinated bank. Your inverter sees one large battery, not a collection of individuals competing with each other. For anyone building a serious off-grid system, this is the correct way to scale storage.
Rack Base for a Clean, Stable Install
A parallel battery bank is only as reliable as its physical installation. The included ETHOS Rack Base gives your stacked batteries a stable, level platform — no stacking directly on a concrete floor, no wobble, no stress on the cable connections. For homestead and cabin installations where temperatures swing and vibrations from equipment are common, a proper rack base prevents connection fatigue over years of use. This is the kind of detail that separates a system that holds up from one that fails at the worst possible moment. Off-grid proven hardware, built to sit in your battery enclosure and do its job quietly for a decade.
Compatibility Check
This parallel kit is designed specifically for ETHOS battery systems. Confirm your setup meets these conditions before ordering.
- Compatible with ETHOS series batteries configured for parallel operation
- Supports up to 4.9 ft inter-battery spacing with included cables
- Requires ETHOS rack-mount battery configuration
Where This Kit Fits
Designed for builders expanding an existing ETHOS battery bank to meet growing energy demands.
Cabin Battery Bank Expansion
Homestead Parallel Scaling
Backup Power Capacity Increase
Full specifications
At a glance
- Power
- 4.9 ft (1500mm)
- Warranty
- See product page
Full specifications5 data points across 4 categories
Dimensions
| Power Cable Length | 4.9 ft (1500mm) |
|---|---|
| Comm Cable Length | 4.9 ft (1500mm) |
Power & Performance
| Configuration | Parallel |
|---|
Materials
| Rack Base | See product page |
|---|
Compliance & Warranty
| Warranty | See product page |
|---|
The Off Grid Vault Promise
Every product we carry is vetted for real-world performance. If it doesn't meet our standards, it doesn't make the cut.
30-Day Performance GuaranteeIf it doesn't perform as specified, we make it right — uninstalled returns accepted within 30 days in original packaging.
Free System Design ConsultationOur engineers size your system for your actual consumption — no guesswork, no incompatible components.
Free ShippingShips free on all orders, including LTL freight on large systems. No surprise freight charges.
★★★★★
“I parallel two ETHOS batteries for my cabin system using this kit. Cables were the right length for my enclosure, the comm cable synced both BMS units immediately, and the rack base is solid. No compatibility headaches — just connected everything and it worked. Exactly what I needed to scale my storage without starting over.”
Frequently Asked Questions
Individual cables from a marketplace listing carry no guarantee they match your ETHOS battery specifications. Undersized wire means voltage drop, overheating, and potential fire risk in your battery enclosure. This kit is purpose-built for ETHOS parallel configurations — the power cables are correctly gauged, the comm cable matches the ETHOS BMS protocol, and the rack base fits the battery footprint. At $254.95, you are paying for verified compatibility, not a handful of unknown wires that may or may not work when you need them.
Off Grid Vault is an authorized dealer for every brand we carry. When you purchase the ETHOS Parallel Kit from us, your warranty claims go through us directly — not through a third-party ticket queue or a marketplace seller who may not exist next month. We stand behind the products on our shelves because we vetted them before listing them. If a component does not perform as specified, our 30-day performance guarantee covers uninstalled returns, and manufacturer warranty support continues through us as your dealer.
This kit includes the cables and rack base needed for a standard parallel connection. The exact number of batteries you can parallel depends on your specific ETHOS model and its BMS parallel capacity — consult your battery's documentation for the manufacturer's maximum parallel unit count. If you are unsure about sizing your battery bank for your daily kWh consumption, take advantage of our free system design consultation. Tell us your loads and setup, and our engineers will spec the correct configuration before you buy.
No. The ETHOS Parallel Kit is designed specifically for BigBattery ETHOS series batteries. The power cable connectors, comm cable protocol, and rack base dimensions are matched to ETHOS form factors. Using these components with a different battery brand creates compatibility risks — incorrect connector fit, no BMS communication, and potential electrical faults. If you are running a different battery line and need a parallel setup, contact us. We carry parallel kits for multiple battery platforms and can point you to the correct hardware for your specific configuration.
This kit ships free via standard ground shipping. Processing and transit times vary based on your location, but most orders arrive within 5–10 business days. Larger system orders that include LTL freight may have different lead times — we communicate real timelines, not fabricated estimates. If you need this kit by a specific date for an installation, reach out before ordering and we will confirm current stock and shipping windows honestly.
The ETHOS Parallel Kit is manufactured by BigBattery specifically for ETHOS series batteries, so connector fit is not a guessing game. However, if you receive a kit and anything does not match your battery model, our 30-day performance guarantee covers uninstalled returns in original packaging. We are also here to verify compatibility before you order — send us your ETHOS model number and we will confirm this is the correct kit for your units. That is what an authorized dealer does.
The Off Grid Vault Promise
Every product we carry is vetted for real-world performance. If it doesn't meet our standards, it doesn't make the cut.
30-Day Performance Guarantee
If it doesn't perform as specified, we make it right — uninstalled returns accepted within 30 days in original packaging.
Free System Design Consultation
Our engineers size your system for your actual consumption — no guesswork, no incompatible components.
Free Shipping
Ships free on all orders, including LTL freight on large systems. No surprise freight charges.
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About bigbattery battery kit
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