The newly upgraded WattCycle 5120Wh server rack battery delivers stronger performance at the same price. It uses BYD Grade A LiFePO4 cells, support 1C charge/discharge speed, 3A active balancing, and a 100A intelligent BMS, all supported by touchscreen, Bluetooth, and CAN monitoring.

WattCycle battery Black Friday deals start on Nov 5 to Nov 28. Offering up to 60% off for LiFePO4 batteries plus an additional 8% code when you subscribe. Visit the WattCycle black Friday sale special page for daily flash sale times. It’s perfect timing to lock in Black Friday battery deals before holiday trips. Get your additional Battery Coupon Code: BlackFriday8% Enter the battery coupon code to receive an additional 8% discount at checkout. At-a-glance Deal Highlights Quick snapshot: WattCycle Black Friday batteries event runs Nov 5–Nov 28. Offer up to 60% off for LiFePO4 batteries, ideal for anyone hunting black Friday battery deals. Double and triple points: Earn 2X Wattpoints during the sale and 3X on Black Friday (on Nov 28). Points are redeemable for coupons, batteries, and limited rewards. Instant signup bonus: Subscribe by email for an immediate 8% code and a free spin on the Lucky Wheel. Lucky Spin wheel: Win batteries (12V 8Ah, 20Ah, 50Ah), monitors, or 8%–10% discount codes. Accessories clearance: All accessories are 15% off during the event, include fuses, switches, monitors, and lithium battery chargers. Flash sales: Daily timed flash deals offer the year’s lowest guaranteed prices on selected items; stock is limited. Extended Cyber Monday window: Nov 28–Dec 1 brings restocks and extra accessory bundles to help finish your energy system. Price protection: A 30-day price protection policy ensures you lock in the best price or receive an adjustment. How Wattpoints work and how to get the most value Wattpoints is WattCycle member point rewards currency you earn with each order. During the Black Friday window you get 2X points, and on Black Friday purchases get 3X. Points are redeemable for discount coupons, replacement batteries, or limited rewards such as a limited edition WattCycle T-shirt valued at $189, a baseball bat valued at $159, a 200A fuse, or a 500A monitor. Lucky Spin wheel Signing up gets you an instant 8 percent discount and entry to the Lucky Spin wheel. Prizes include LiFePO4 lithium batteries such as 12V 8Ah, 12V 12Ah, 12V 20Ah, and 12V 50Ah batteries, monitors, plus 8% or 10% discount codes. Coupons won on the wheel typically have long validity and can be used later or gifted. Use any spin prize as a way to cover shipping or a small accessory so your main battery purchase keeps its coupon. Even modest wins add up when combined with Wattpoints and accessory discounts. Recommended Accessories Discount Sale Accessories are 15% off during the main event, which is the fastest way to finish a system affordably. The sale covers fuses, switches, circuit breakers, monitors, lithium chargers, and mounting kits. Suggested bundles to consider: Marine starter kit: 200A/250A fuse ($15.99), 14.6V 20A LiFePO4 battery charger ($109.99), 12V 100Ah BT trolling motor battery ($199.99) to get a simple 12V install. RV essentials: 200A battery switch ($39.99), charger, 500A LiFePO4 battery monitor ($79.99) and 12V 100Ah Group 24 battery ($169.99) for reliable on-road power. Solar backup pack: 14.6V 40A LiFePO4 battery charger ($159.99), 30A MPPT solar charge controller ($119.99), 500A LiFePO4 battery monitor ($79.99) and 12V 314Ah Mini battery (399.99) to pair with your solar system. Buying compatible accessories during the event reduces troubleshooting later and often costs less than purchasing items singly after the season ends. Lowest Price Guarantee WattCycle offers 30 days price protection policy during the promotion. All user are covered by a 30-day price protection policy to ensure they secure the best available price during the promotion. Get Your Discount Now Earn 2X Wattpoints during Nov 5 to Nov 28 and get 3X points on Black Friday to stack further discounts. For product-specific flash sale times and exact listings, visit the official WattCycle US site. Whether you need a 12 volt marine deep cycle battery, a modular pack for solar backup, or an RV and camper van 100Ah battery, the event makes it easier to complete your setup affordably and with confidence.

We have released an official Bluetooth App update that resolves the reported parallel “Take Turns” discharge issue and adds two parallel modes to the WattCycle App. This update improves reliability when batteries are used in parallel and makes mode selection clearer. The core changes are: device name display fixed, a parallel on/off control added to the App, and two selectable parallel modes: ExactMatch Mode and Compatibility Mode. Below is an WattCycle official guide to the update and correct usage. Key updates at a glance Device name display fixed. Each battery now shows its correct name in the App for easy identification. Parallel on/off control added. Turn parallel operation on or off from the device settings. Two parallel modes added: ExactMatch Mode and Compatibility Mode. BMS over-current protection remains active in both modes and will protect the battery and connected equipment as needed. Why we fixed the parallel-discharge issue After user reports, we audited the App to BMS communication logic and corrected the interaction that could lead to alternating discharge behavior. The fix is included in this official versions. Please ensure your App and battery firmware are updated to the latest version before returning your system to production use. Parallel modes and recommended use ExactMatch Mode Intended use: Parallel groups composed only of WattCycle batteries of the same voltage. In this mode the App and BMS apply tuning that matches cell chemistry, internal resistance, and capacity so charge and discharge are coordinated across the battery bank, minimizing voltage and SOC (state-of-charge) divergence and improving balancing speed and thermal uniformity for LiFePO4 cells. For best performance and longest service life choose ExactMatch when every parallel unit is the same WattCycle battery. Standard BMS protections, including over-current protection, cell over-voltage and under-voltage protection, and low-temperature cutoff, still remain active in this mode. Compatibility Mode Intended use: Parallel combinations where WattCycle batteries are mixed with batteries from other brands or with different models and capacities. This mode uses more conservative balancing thresholds and coordination logic to allow safe interoperability, so packs with differing characteristics can operate together with reduced risk of conflict; when there is a large mismatch in capacity or internal resistance the battery bank may show a brief delay between reaching full charge and the start of discharge, an uncommon effect that is usually negligible in normal use. Use Compatibility Mode only when mixing brands or models is necessary and monitor battery voltages and SOC regularly. As always BMS over-current and cell protection functions remain enabled to safeguard the system. Safety and best practices Before paralleling, confirm each battery is healthy and that voltages and state of charge are similar. Prefer ExactMatch Mode for long term parallel use when all batteries are the same model. If you must mix batteries, use Compatibility Mode and check battery bank behavior regularly. Avoid long term mixing of batteries with large capacity or health differences when possible. BMS over-current protection will remain enabled and will act to protect the battery and connected loads in abnormal conditions. If you experience any unexpected behavior after updating, please contact WattCycle support with your device model and serial number. We will continue to monitor feedback from this internal release and refine parallel handling as needed. Thank you for using WattCycle and for your help testing this update.

When your vessel will be idle for an extended period, we recommend disconnecting the boat battery to prevent parasitic and accidental discharge and to prolong LiFePO4 service life. If constant power is required, consider a dedicated battery switch, a LiFePO4 compatible charger, or a small solar array with controller. Why Disconnect? Even when your boat is “off,” small electrical draws continue: navigation displays on standby, alarm and monitoring circuits, battery management systems, bilge pump float switches, and wiring faults can all create a continuous (parasitic) drain. Over weeks or months that steady draw lowers state-of-charge (SoC), increases the number of partial discharge-recharge events and if left unchecked can allow the pack to reach the BMS low-voltage cutoff. That sequence shortens useful service life and may leave you with a depleted marine battery the next time you head out. Disconnecting the battery eliminates these parasitic loads at source. For LiFePO4 chemistry, which already benefits from low self-discharge and robust cycle life, removing continuous standby drain prevents unnecessary shallow cycling and reduces the chance of repeated low-voltage events that stress cells and trigger BMS protective actions (low-voltage disconnects, balancing activity, or over-current lockouts). A simple real example: during a multi week marina layup or winter storage, an unattended alarm or a slow parasitic leak can pull enough current to take a 12V deep cycle marine battery from a healthy SoC down to the BMS cutoff over a few weeks. For longer storage (several weeks to months), best practice is to disconnect or isolate the battery and store it at a moderate SoC (commonly around mid-charge) rather than fully charged or fully discharged. This approach reduces stress on the cells and makes a reliable restart far more likely. When you Should Keep the Battery Connected Some onboard systems must remain powered even when the boat is idle. Typical always-on loads include bilge pumps and float switches, alarm and intrusion sensors, GPS/telemetry or tracking devices, and automatic battery chargers or monitoring equipment. If any of these circuits are required for safety or regulatory reasons, you should not fully isolate the battery. Keeping a LiFePO4 house battery connected is acceptable when you apply the right safeguards: Separate critical loads: Put safety circuits (bilge pump, alarms, tracker) on a dedicated branch or a separate starter/backup battery when possible so a single parasitic fault cannot drain all marine batteries. Proper over-current protection: Fit a battery side fuse or circuit breaker sized to protect the cable and to coordinate with the battery’s BMS rating. As an example, a WattCycle 12V 314Ah battery with Bluetooth and a 200A BMS should use a suitably rated 200A ANL or equivalent breaker and heavy-gauge cable (short runs commonly use 2/0 AWG); always confirm with wiring Ampacity tables and installation distance. Reliable float/maintainer source: If the battery stays connected long-term, provide a LiFePO4-compatible shore charger or a correctly configured solar charger. Set float/maintenance voltage in the 13.4–13.6 V range for most LiFePO4 systems and use a charger that supports a dedicated LiFePO4 battery. Isolation and switching: Use a quality marine battery switch, voltage sensing relay, or DC isolator so you can quickly disconnect non-essential circuits without disturbing required safety loads. Monitoring and periodic checks: Pair the battery with WattCycle Bluetooth/BMS monitoring or other telemetry so you can see SOC, temperature, and any BMS events remotely; check the system periodically (weekly or biweekly for extended stays). These measures let you leave essential boat systems powered while minimizing the risk of unintended discharge and preserving the long-term health of your LiFePO4 marine battery. Practical Options and Recommendations For most recreational boat owners the single best starting point is a marine rated battery disconnect switch for simple isolation. We recognize that fully removing battery cables is often impractical and time consuming for many owners, and that some onboard systems such as bilge pumps, alarms and trackers require continuous power. Physically disconnecting and reinstalling wiring usually requires tools and careful handling, and there is a real risk of forgetting to reconnect the battery before your next trip. If the boat must remain powered for safety systems, use a dedicated LiFePO4 maintainer or a correctly sized solar array with an MPPT controller. Always pair any arrangement with a WattCycle smart battery that includes BMS and Bluetooth monitoring, and protect circuits with fuses or breakers sized to the battery and cable run. Battery disconnect switch Install a marine rated battery disconnect such as a terminal lever, rotary, or removable key type sized at or above your BMS continuous rating. A quality switch is an inexpensive, low complexity solution that immediately eliminates parasitic draw, requires minimal maintenance, and greatly reduces the chance of arriving to a discharged boat after a multi week or winter layup. Note that a switch isolates the battery but does not maintain the state of charge, so include it in a broader storage checklist. Small solar system with charge controller For off grid system, a modest PV array paired with an MPPT charge controller configured to LiFePO4 float voltages will provide automatic, maintenance free topping. Estimate panel watts from your expected standby draw using daily Ah = standby A × 24 and convert to required watts using peak sun hours and a conservative system derating. As guidance, allow roughly 20 W for about 0.1 A standby draw, 50 W for about 0.5 A, and 100 W for about 1.0 A. Use marine grade panels, an MPPT controller rather than PWM, correct float settings of 13.4 to 13.6 V, properly sized fusing, and sealed connections. An undersized or poorly configured solar system can become a single point of failure. WattCycle BMS and Bluetooth monitoring Real time telemetry from WattCycle’s BMS and Bluetooth interface provides visibility of SOC (state of charge), voltage, temperature, and charging/discharging switch so you can identify parasitic drains or abnormal conditions before they cause operational problems. Monitoring is most effective when paired with a disconnect strategy or a maintainer or solar arrangement. Use monitoring to validate float settings, receive early alerts for over-current or low voltage conditions, and support proactive maintenance that improves long term performance and availability of your LiFePO4 marine battery. When the battery must remain connected If a battery must stay connected long term, for example to supply a bilge pump, alarm system, or tracking device, apply deliberate protections so the battery remains available and the LiFePO4 battery bank is not exposed to unnecessary risk. Key measures include correctly sized over-current protection at the battery positive, a reliable isolation method so nonessential circuits can be taken offline, redundancy for safety loads, and a regular inspection routine. Situation Recommended Strategy Key Safeguards Short-term absence (<2 weeks), no required always-on loads Disconnect battery or use a battery switch to isolate Basic isolation only; store at mid SOC if removed Short-term absence (<2 weeks), essential safety loads present Keep connected with small solar controller system Inline fuse/breaker, monitoring, weekly checks Long-term storage (≥2–4 weeks), no essential loads Fully isolate or remove battery from vessel Battery stored at ~40–60% SOC; periodic top-up every 3–6 months Long-term storage (≥2–4 weeks), essential loads present Solar + MPPT and monitoring Battery-side breaker, dedicated circuit for safety loads, redundant pump battery recommended Boat in water (moored/anchored) with bilge pump Keep safety circuits powered; consider dedicated pump battery Dual-battery or isolated pump battery, fuse, VSR/isolator, remote alerts Boat out of water (on trailer/hoist) and no loads Disconnect battery Store in dry, moderate temperature; periodic SOC check When your boat will be idle for more than a short period, the safest and most effective practice is to disconnect the battery or use a proper marine battery switch. This prevents unnecessary standby draw, protects the LiFePO4 cells, and ensures your system is ready for the next trip. The only safe exceptions are when critical devices such as bilge pumps or alarm systems require continuous power, safeguards such as correctly sized fuses, isolation methods, and monitoring become essential. WattCycle One-stop Solution WattCycle offers a full line of 12V deep cycle marine batteries designed with advanced BMS features, Bluetooth monitoring, and over-current protection to support safe operation whether the battery is disconnected or left connected for essential loads. We invite you to explore our WattCycle marine battery product pages, download detailed datasheets; WattCycle 12V 100Ah trolling motor battery, purpose-built for water environments with an IP67 waterproof rating and built-in Bluetooth monitoring, or the 12V 100Ah marine dual purpose battery, which combines starting capability (1200 CCA) with deep cycle performance, smart Bluetooth and IP67 waterproof rating also. Whether you are upgrading a single 12V deep cycle marine battery or planning a complete lithium boat battery system, WattCycle experts are available to help specify the right setup and answer installation questions.

The behaviour is the expected result of deliberate BMS protection logic (designed to protect individual cells) interacting with parallel system electrical conditions.

Both overcharging and undercharging sneakily sap your battery’s strength over time. Pushing voltage too high without the right cut-off can stress cells, leading to capacity fade or safety risks, even when your BMS over-current protect is in place.