Category Archive: Battery

How to Connect Batteries in Series and Parallel

Sager Power Systems, a specialized group of Sager Electronics, offers a dedicated sales force of power systems sales engineers concentrated on power, thermal management and battery solutions with the unique position of providing traditional distribution services and value-added design. Sager is focused on bringing our customers the newest products, technical design information and design support to support our customers’ application requirements.

Series, Series-Parallel and Parallel is the act of connecting two batteries together. By connecting two or more batteries in either series, series-parallel or parallel, you can increase the voltage or amp-hour capacity, or both to allow for higher voltage applications or power hungry applications. Power Sonic explains these connection types below.

Connecting Batteries in Series

Connecting a battery in a series is to connect two or more batteries together to increase the battery system’s overall voltage. Connecting the batteries in a series does not increase the capacity only the voltage. For example, connecting four 12-volt 26Ah batteries you will have a battery voltage of 48-volts and a battery capacity of 26Ah.Contact Sager Power Systems for Your Battery Requirements

To configure batteries with a series connection, each battery must have the same voltage and capacity rating. Connecting batteries of different voltages could result in damage to the batteries. Connecting two 6-volt 10Ah batteries together in a series is a strong example of proper connection, while connecting one 6-volt 10Ah battery with one 12-volt 10Ah battery is not.

To connect a group of batteries in series connect the negative terminal of one battery to the positive terminal of a second battery and so on until all required batteries are connected. From this stage, connect a link or cable to the negative terminal of the first battery in the battery string to the application. A second cable is then attached to the positive terminal of the last battery to the application.

When charging batteries in series, you need to use a charger that matches the battery system voltage. It is recommended each battery is charged individually to avoid battery imbalance as each battery may be at a different charge level.

Sealed lead acid batteries have been the battery of choice for long string, high voltage battery systems for many years, although lithium batteries can be configured in series attention is required to the BMS or PCM.

Connecting Batteries in Series

Connecting Batteries in Parallel

Connecting a battery in parallel is when you connect two or more batteries together to increase the amp-hour capacity. With a parallel battery connection the capacity will increase, but the voltage will remain the same. For example, connecting four 12-volt 100Ah batteries would result in a 12-volt 400Ah battery system.

When connecting batteries in parallel, the negative terminal of one battery is connected to the negative terminal of the second battery and so on throughout the battery string. This same approach is taken with the positive terminals, with one positive terminal connected to the positive terminal of the next battery. By way of example, for a 12-volt 300Ah battery system, three 12-volt 100Ah batteries would be strung together in parallel.

Parallel battery configuration helps increase the duration in which batteries can power equipment, but due to the increased amp-hour capacity, this configuration can take longer to charge than series connected batteries.

Connecting Batteries in Parallel

Series – Parallel Connected Batteries

Series-parallel connection is the connection of a string of batteries to increase both the voltage and capacity of the battery system. Connecting six 6-volt 100Ah batteries together to create a 24-volt 200Ah battery system is achieved by configuring two strings of four batteries. In this particular connection, two or more sets of batteries will be configured in both series and parallel to increase the system capacity.

Series – Parallel Connected Batteries

Examples of Batteries Connected in Series and in Parallel

Batteries Connected in Series and in Parallel
Batteries Connected in Series and in Parallel

Power Sonic Battery Solutions

Power Sonic has been manufacturing sealed lead acid batteries since 1970 and offer one of the most comprehensive battery ranges within the industry. The following is a sampling of the industry leading battery solutions from Power Sonic:

PS Series Rechargeable Sealed Lead Acid Batteries

Overview Page


Product Catalog


  • General purpose VRLA battery
  • Absorbent Glass Mat (AGM) technology for superior performance
  • Power and volume ration yielding unrivalled energy density
  • VdS approved models
  • Valve regulated, maintenance free spill proof construction
  • Rugged impact resistant ABS case and cover flame retardant to UL94:HB and UL94:V0
  • Low discharge rate for long shelf life
Power Sonic PS Series Rechargeable Sealed Lead Acid Batteries

PG Series Batteries


Product Catalog


  • Long service life VRLA battery
  • Superb high-rate discharge characteristics
  • Absorbent Glass Mat (AGM) technology for superior performance
  • Lead-calcium alloy grids and use of high purity lead account for superior shelf-life characteristics
  • Thick plate design and efficient gas recombination for a design life expectancy of up to 12 years in standby mode
  • Proven valve regulated technology to guarantee safe operation
  • Rugged impact resistant ABS case and cover, available to UL94:V0 flame retardent
 Power Sonic PG Series Batteries

PSL-SC Series of Series Connection Lithium Batteries



  • Super safe lithium iron phosphate (LiFePO4) chemistry
  • Higher capacity or voltage capability through parallel or series connection
  • Delivers twice the power of lead acid batteries, even at higher discharge rates while maintaining constant power
  • Smart battery system (BMS) controls the parameters of the battery to provide optimum safety and battery life
  • Compact design and only 40% of the weight of comparable lead acid batteries
  • Faster charging and lower self-discharge
  • Up to 10 times longer cycle life than lead acid batteries
  • Rugged impact resistant ABS case and cover
Power Sonic PSL-SC Series of Batteries

The Challenges of Designing and Sourcing Power Supplies and Batteries

Every electronic application requires some form of power source, but designing and sourcing power supplies and batteries can be challenging. Customers often face potentially complex solutions, long design cycles, extended lead times, and a lack of expert design guidance. Because power and power-related products are some of the most complex in terms of design and procurement, a number of key factors must be considered when designing power.  

Power Supplies

Engineers and purchasing professionals must weigh many factors including an understanding of the end application, including any portability requirement. Some of the questions to ask; What is the size, output power, efficiency, and reliability needed? How will heat be managed and what means of thermal management is required? For instance, should the power supply be fan-cooled, convection, or conduction cooled?  Are there safety concerns and at what level (e.g., Class 2 vs. Class II)? Is interference an issue and does the device require EMI/RFI filtering? How long will the device run and what are the peak power loads that are required? Does the application require an uninterruptible power source or a battery backup? 

A technical power supply distributor such as Sager Electronics through its specialized group Sager Power Systems is often the key in helping a customer address these types of design challenges. Sales engineers can assist customers in determining the correct power and battery backup solution. Recommendations may include several design options from off-the-shelf AC-DC power supplies and DC-Converters to modified standard products that range from simple modifications to highly complex design. 

Battery Backup

The power grids across the United States face major challenges due to infrastructure age, intense weather, and the increase in demand for electricity. Electrical outages, brownouts, and surges are a reality, and these factors need to be strongly considered when designing electronic systems.  This is especially so for equipment manufacturers in the industrial and medical sectors where down time can lead to major financial loss or potentially life-threatening situations. The growth of home health care devices like respirators, CPAP machines, power wheelchairs, and home dialysis equipment are essential to quality of life and independence, and these systems all require battery backup. To address the demand for portable and backup power requirements, Sager added RRC Power Solutions, a lithium-Ion smart battery pack manufacturer, and Power Sonic, a leader in sealed lead acid and lithium-Ion technology, to its line card.


Power sources tend to have a higher value and are often larger and weigh more than most components, impacting shipping methods and costs. Batteries also present some additional buying challenges specifically around shelf-life,  recycling considerations, and shipping and handling regulations. Lead times should be monitored as extensions on power supplies and batteries can present a challenge. Price, availability and handling make proper planning crucial in the procurement of power supplies and batteries.   

“The Sager Power Systems program is very unique to the marketplace. With a focus on power and synergistic technologies such as batteries and thermal management solutions, and the ability to provide best-in-class configurable and custom value-add services , no other distributor offers its customers this level of expertise in power and thermal,” explained Rich Arieta, Sager’s director of business development for Sager Power Systems. “Additionally, we can further support our customers’ requirements with a comprehensive array of supply chain services.”

In today’s quick and complex market, access to knowledgeable technical advice, breadth of quality product, and reliable service is paramount to successful design. 


Need a Custom Battery Pack? Know These 5 Critical Details First.

Reliable battery power is a critical piece in today’s portable world. Custom battery pack solutions across the medical, military, and industrial/commercial markets can vary widely.

Identifying the battery pack solution that will work best for your specific product is the tricky task.

Here are five key questions that you should be able to answer for your next battery product design:

1. What space is available for the battery power?

Do you have a sketch or drawing of the product you are building? Do you have dimensions of the space the battery should fit in?

Or are you early in your design process? Perhaps you still have flexibility on the form the battery pack needs to take.

This is a critical piece to plan for.

2. How long do you need your device to operate between charges?

This information is important because it indicates how much capacity (Ah) is needed when choosing a cell size and chemistry. One significant limitation, even a trade-off, is the space that is available for the battery.

3. What agency testing will be required?

The agency testing that is required will depend on the type of device and the market for which you’re building. The design of the custom battery pack inside your device may all or in part depend on the agency testing needed.

For instance, the drop test required for IEC 62133 will likely mean that the battery will need to be in a plastic case or at least protected with foam bumpers.

Some frequently required agency tests are: UL 2054, IEC 62133, and as well those referenced in the UN Manual of Tests and Criteria 38.3.

This can be a challenging aspect of the battery design process. We will work with you to verify the testing that is needed, and modify and evolve your battery design to successfully meet the requirements.

4. What battery chemistry is under consideration?

Do you already have product design requirements that justify using a particular chemistry for the battery? The chemistry of the battery will determine the functionality with regard to weight, form factor, capacity, voltage, energy density, and more.

We work with a wide variety of chemistries including:

  • Sealed Lead Acid (2v/cell)
  • Nickel Cadmium (1.2v/cell)
  • Nickel Metal Hydride (1.2v/cell)
  • Li-Ion derivatives including Cobalt Oxide (3.7v/cell), Nickel Manganese Cobalt (3.6V/cell), Nickel Cobalt Aluminum (3.6v/cell), Lithium Iron Phosphate (3.2V/cell), and Lithium Titanate (2.4v/cell)

5. What conditions will the device and battery pack be subjected to on a daily basis?

You’ll want to consider four areas (if not more) that might affect the device and/or battery:

  • Operating and storage temperature of the product
  • Continuous, average and peak discharge currents
  • Operating voltage range of the battery and device
  • Battery charger rate and method of charging

The answers to these will vary, but they can be incredibly helpful to getting the proper start on your custom battery pack design.

The right provider will be asking you these key questions upfront. You will save time, error, and ultimately cost in the long run by knowing as much about your requirements as you can early on.

If you have flexibility in your design, one of our off-the-shelf battery designs may save you time and money.

Or you can click here to request a quote for your specific project.