Details on new solar-specific AGM battery line from Trojan Battery

Trojan Battery Co., LLC, the world’s leading manufacturer of deep-cycle batteries, today announced the launch of its new line of maintenance-free, true deep-cycle absorbent glass mat (AGM) batteries specifically designed for solar and other renewable energy applications. The new Trojan Solar AGM line is manufactured in the U.S.

Solar AGM

Offering a three-year warranty for stationary applications, and tested to an eight-year design life under IEC 61427 standard for solar batteries, this initial release includes a wide range of Trojan Solar AGM models. With its non-spillable design, the new Trojan Solar AGM batteries enable installers to customize the use and position of the batteries in customer applications, and are certified for non-hazardous shipping per U.S. DOT/IATA regulations.

The Trojan Solar AGM line of batteries will be showcased at Intersolar Europe this week in Munich at the Trojan Battery booth B1.260.

“As we continue to see strong customer interest and demand in applications such as residential storage (both off-grid and grid-tied), solar home systems, microgrids, remote telecom, as well as oil/gas, Trojan’s new line of true deep-cycle Solar AGM batteries has been designed from the ground up and optimized for these types of solar applications and the need for frequent cycling in harsh environments,” said Ganesh Balasubramanian, director of new market development for Trojan Battery. “Trojan continues to remain the only global battery manufacturer to engineer, and produce only deep-cycle batteries, and now we have leveraged our 90 years of deep-cycle flooded experience into engineering and manufacturing the best cycling AGM battery line batteries for solar applications worldwide.”

Is there a PV storage solution between lead-acid and lithium ion?

The new Trojan Solar AGM battery line extends Trojan’s robust offering of maintenance-free, deep-cycle batteries specifically designed for renewable energy applications. This battery family joins Trojan’s current Smart Carbon deep-cycle flooded batteries which feature Trojan’s proprietary carbon additive that helps reduce the effects of Partial State of Charge (PSOC) or undercharging which is common in renewable energy applications. Operating at PSOC on a regular basis can quickly diminish the overall life of a battery, which results in frequent and costly battery replacements.

“With batteries being one of the most expensive components of a battery-based solar system, it is critical to maximize the life of the battery bank to reduce the total cost of ownership of a system,” said Michael Grundke, general manager of EMEA for Trojan Battery. “Trojan’s new Solar AGM line illustrates the company’s commitment to offering reliable energy storage solutions for a wide range of renewable energy market segments. Trojan continues its focus on being an innovative leader in the energy storage space.”

Trojan’s Solar battery line incorporates a wide range of advanced technical features including a robust proprietary paste, advanced plate design and premium separators for overall extended lifecycle, and optimized for total cost ownership. In addition, Trojan’s new deep-cycle Solar AGM batteries are temperature tolerant, shock and vibration resistant and have a low internal resistance for higher discharge current and higher charging efficiency. These features make it the ideal battery for the harsh and demanding environments of off-grid as well as grid-connected systems with frequent cycling needs.

— Solar Builder magazine

This new residential battery management system is available via Open Source License

Battery Bank

The Digital Microgrid Initiative P.B.C. (DMI), is a public benefit corporation organized to provide clean, reliable and inexpensive electric power to remote areas where grid power is unreliable or non-existent. All profits are reinvested to provide more cost-effective solutions to further the company’s mission of providing clean, low-cost electric power where the need is greatest. The first Digital Microgrid products will be shipped in June and will include a highly modular family of off-grid solar energy systems with a starting price of under $5,000.

DMI’s next move is to make its residential battery management system (BMS) available to battery manufacturers and others under an MIT Open Source License. The BMS hardware is used as a building block providing safety and longevity for batteries in residential energy storage applications. DMI’s hardware is designed to handle a variety of battery chemistries. Within DMI’s solar power systems, batteries of various capacities and characteristics can be mixed to allow simple expansion and system growth to megawatt and megawatt-hour capacity.

Co-President Gene Krzywinski describes why DMI is sharing it’s technology: “Unlike other home appliances, residential grid independence is still dependent on proprietary solutions. We want replacing batteries in home energy storage to be as simple as putting an AA cell in your TV remote.”

Bill Southworth, DMI co-President, describes the market need: “All residential solar power in the future will live hand-in-hand with residential energy storage. Independent solar installers will continue and expand their role as the main retail provider of home solar. As the solar market continues to expand while net metering declines, the majority of new homes and apartments will incorporate solar independence into their construction. We all need simpler and more standardized solutions.”

Inside the system

For battery manufacturers and equipment developers interested in the Open Source program as well as other cooperation on standards, DMI will publish schematics, materials list, API specifications, PC layout and fabrication (Gerber) files. The 80×120 mm BMS is isolated for use in high voltage packs and will manage LiFePO4, lithium titanate (LTO), AGM, and NMC packs. Multiple BMS cards may be used with multiple 48 volt packs in a single high voltage battery. The BMS cards jointly report cell state-of-charge and provide cell balancing on each cell in the battery. A published API is provided describing the communication protocol. The BMS cards are programmed for maximum and minimum cell voltage, but can also be used with sophisticated learning systems for SOC optimization in a dynamic environment such as residential solar. In the DMI system, each battery has its own 8 kW charge/discharge controller and an unlimited number of batteries can be used on a 380 volt bus for megawatt level solutions.

Top 5 battery installation issues for solar installers

— Solar Builder magazine

Smart grid, battery storage companies see big jump in funding to start 2017

Mercom Capital Group, llc, a global clean energy communications and consulting firm, released its report on funding and mergers and acquisitions (M&A) activity for the Battery Storage, Smart Grid, and Energy Efficiency sectors for the first quarter of 2017.

Smart Grid

Venture capital (VC) funding (including private equity and corporate venture capital) for Smart Grid companies increased threefold in Q1 2017 with $164 million in 14 deals compared to $46 million in six deals in Q4 2016. In a year-over-year (YoY) comparison, in Q1 2016 $110 million was raised in 14 deals.

renewable energy investment

The top VC funded Smart Grid companies included: ChargePoint, which secured $82 million from Daimler, BMW I Ventures, Linse Capital, Rho Capital Partners, and Braemar Energy Ventures; Urjanet raised $20 million from Oak HC/FT; POD Point received $11 million from Draper Esprit and Barclays Capital; Blue Pillar secured $10 million from GXP Investments, Elevate Ventures, EnerTech Capital, Allos Ventures, Arsenal Venture Partners, and Claremont Creek Ventures; and Enchanted Rock raised $10 million from Energy Impact Partners.
Forty investors participated in Smart Grid VC funding rounds this quarter with Smart Charging of PHEV and V2G companies raising the most.

There were seven Smart Grid M&A transactions in Q1 2017 compared to two transactions in both Q4 2016 and Q1 2016.

RELATED: SEIA meets with Rick Perry to talk solar innovations, storage and future of the grid 

Battery Storage

VC funding for Battery Storage companies came to $58 million in eight deals this quarter compared to $156 million in nine deals in Q4 2016. YoY funding in Q1 2016 was lower with $54 million raised in 10 deals.
The top VC funded Battery Storage companies this quarter were: Primus Power, which raised $32 million from Success Dragon, Matador Capital, Anglo American Platinum, DBL Partners, I2BF, and the Russia Kazakhstan Nanotechnology Fund; NRStor received $8.4 million in funding from Labourers’ Pension Fund of Central and Eastern Canada (LiUNA) and NRStor founder, Chairman, and CEO Annette Verschuren; Ioxus raised $6.5 million in funding; and Faradion raised $3.95 million in funding from Mercia Technologies, Finance Yorkshire Seedcorn Fund, and Haldor Topsoe.

Fifteen investors participated in Battery Storage funding this quarter with Flow Battery companies raising the most. There were two debt and public market financing deals in Battery Storage this quarter totaling $22 million compared to $55 million in two deals in Q4 2016. There was one Battery Storage project fund announced in Q1 2017 for $152 million.

There were two Battery Storage project funding deals in Q1 2017 that raised a combined $5 million compared to one deal that was undisclosed in Q4 2016. There were no Battery Storage project funding deals in Q1 2016.
There was one M&A transaction involving Battery Storage companies in Q1 2017. In Q4 2016, there were two M&A transactions. In a YoY comparison, in Q1 2016 there were two transactions.

RELATED: Here’s the price of residential solar-plus-storage systems, according to DOE research 


Energy Efficiency technology companies increased VC funding to $213 million in 14 deals this quarter compared to the $170 million in five deals in Q4 2016 and $211 million in 14 deals in Q1 2016.

The Top 5 Efficiency deals included: $100 million raised by View (formerly Soladigm) from TIAA Investments, an affiliate of Nuveen; the $65 million in funding raised by Kinestral Technologies; the $15 million raised by Sense from iRobot Ventures, Shell Technology Ventures, Energy Impact Partners, Capricorn Investment Group, Prelude Ventures, CRV, and hardware accelerator Bolt; and SparkFund raised $7 million from Energy Impact Partners and Vision Ridge Partners.

Twenty-two investors participated in VC funding this quarter. Within the sector, Efficient Home/Building companies brought in the most funding.

Debt and public market financing for Efficiency companies fell to $301 million in three deals this quarter compared to $928 million in five deals in Q4 2016.

There were four M&A transactions in the Efficiency sector this quarter compared to two in Q4 2016. In a YoY comparison, there were three M&A transactions in Q1 2016.

Head here for a copy of the report.

— Solar Builder magazine

LG Chem debuts residential battery system in the U.S.

LG Chem Ltd., a global leader in lithium-ion batteries for automotive, stationary and consumer applications, has formally launched its range of award-winning residential battery systems in the North American market.

LG Chem battery

Battery details

LG Chem’s North American residential battery range offers AC- and DC-coupled solutions with capacities up to 9.8 kilowatt hours (kWh). Two voltage options are available, pre-matched with compatible inverters and suitable for both indoor and outdoor installation:

  • Low-voltage 48V: with capacities of 3.3, 6.5 and 9.8kWh; and,
  • High-voltage 400V: with capacities of 7.0 and 9.8kWh.

The 400V RESU10H (9.8kWh) product is compatible with SolarEdge’s StorEdge, which is a DC-coupled storage solution based on a single inverter for both PV and storage. Additional inverter compatibility options will become available later in 2017 to provide homeowners with a range of pre-tested solutions from the industry’s leading suppliers.

LG Chem’s residential batteries will be available via a number of leading solar/storage providers in North America. Following last year’s announcement of a partnership with LG Chem, Sunrun – one of the leading U.S.-based residential energy system providers – will be supplying LG Chem’s RESU systems. Sunrun already has installed initial systems in both Hawaii and California.


— Solar Builder magazine

Top 5 battery installation issues for solar installers

Battery Bank

With the right installation, battery banks can provide reliable power for years. In this article, you’ll discover how to avoid costly, hard-to-diagnose battery installation mistakes, and you’ll learn a holistic approach that prevents costly errors long before installation.

1. Not Starting with Efficiency

Each additional kWh of energy demand requires extra solar or wind generation, battery storage and backup generation. Thus, it’s cost-effective to start by increasing efficiency.

First steps include replacing inefficient electronics and appliances with Energy Star models, eliminating vampire loads using switchable power strips and adjusting thermostat settings seasonally.

Next, consider adding blown-in insulation to walls and attics. Since nearly half of household energy is used for space heating and air conditioning, this can drastically reduce heating and cooling demands.

Finally, whole-house fans and nighttime ventilation offer inexpensive comfort. And compressor-less Variable Refrigerant Flow HVAC reduces electricity usage by ~90 percent.

2. Improper Sizing

Oversized panels, turbines and batteries waste money, but undersized systems can make everyday living frustrating — and shorten battery life due to deep discharging. The solution? Calculate accurate electrical loads.

After taking steps to improve efficiency, check the past year’s utility bills to estimate power requirements. Affordable devices like Kill-A-Watt accurately monitor individual appliances’ energy usage and reveal vampire loads. From there, the basic calculation for a system’s power needs is: Watts = amps x volts

For instance, if 1,000 watt-hours (1 kWh) a day are needed, a 12-volt / 84 Ah battery bank (1,008-watt capacity) will not address power demands because the battery would be exposed to 100 percent depth of discharge every cycle.

Experts recommend sizing your system based on a maximum of 50 percent depth of discharge (DoD). In the example above, the battery bank would need to be sized to 12 V / 168 Ah — double the estimated Ah requirements.

Note that some battery manufacturers size systems based on 80 percent or 100 percent DoD. This assumption can provide inadequate reserve power for heavy loads during heat waves and frigid winters or for cloudy or foggy days with low solar production. Batteries discharged by more than 80 percent lack reserve capacity to power high-energy appliances or even keep the lights on.

3. Choosing the Wrong Batteries for the Application

There’s no one-size-fits-all battery. Instead, key factors include ambient temperature, technology, desired voltage, maintenance, sustainability/recyclability and cost.

Lead-acid batteries are the most common for renewable systems. Refined over 100-plus years, they’re longer lasting and 50 to 90 percent less expensive than other technologies. According to the EPA, lead-acid batteries are 99 percent recyclable — more recyclable than an aluminum can.

Options include flooded batteries, which offer the highest ROI but require periodic water adjustment and other preventive maintenance, sealed valve-regulated lead-acid (VRLA) batteries and zero-maintenance options that are more expensive.

RELATED: Is there a PV storage solution between lead-acid and lithium ion? 

Lithium-ion batteries don’t require maintenance and offer the highest power density (and thus, lightest weight). For lithium-ion batteries, battery management systems (BMS) are required to prevent overcharging and to reduce the risk of house fires and explosions caused by thermal runaway. Li-ion’s cost per Ah is the highest and they are zero to 60 percent recyclable.

BMS is not required for lead-acid and many other battery chemistries, but BMS is beneficial because features like temperature-based charging, total and per-cell voltage and DoD monitoring help increase capacity and minimize damage caused by temperature extremes.

Whatever technology you choose, only buy deep-cycle, renewable batteries designed specifically for heavy cycling.

4. Improper Wire Sizing

Wire size varies based on amps carried and how many feet electricity must travel. Often, undersized cables are the hard-to-diagnose cause of system failure.

Just as water needs enough pressure to travel through a garden hose, an electric current must have enough voltage to travel. And much like a garden hose, electrical current must exceed pressure (impedance or resistance) caused by wire shape, thickness, length and other variables.

When cables are too small, voltage drops and makes the load work harder. This can cause lights to flicker, heaters to underperform and motors to burn out early. Worse, undersized cables can generate heat and even start fires. A smaller AWG means a larger cable. To calculate ideal wire size, use a “wire gauge calculator” and specify no more than a 3 percent voltage drop.

5. Improper Storage

Batteries last longest at or around 77˚ F. Every 18° F temperature increase drops available cycles by 50 percent. The cold reduces available capacity exactly when solar production is lowest and energy demands are highest.

The only solution to this problem is protecting batteries, but common storage solutions such as insulated coolers and old refrigerators offer little buffer against the cold, and they trap so much summertime heat that battery temperatures often exceed 140° F.

A better solution is storing batteries in a well-insulated, enclosed structure, either inside the home or in a properly vented box in a garage or shed. To do this, arrange batteries to ensure 1/2-in. air gaps and allow for easy maintenance. Never install breakers, switches or spark-producing devices inside an enclosure — this could cause an explosion.

The best approach uses standalone systems such as EMPUS, an insulated structure that maintains ideal operating temperatures year-round, to maximize the lifespan of batteries and electronics.

John Connell is VP of Crown Battery’s SLI Products Group.

— Solar Builder magazine