Epec's Blog | Electronics Manufacturing Solutions

When building a lithium-ion battery pack, there will always be some sort of protection circuitry necessary that will safely separate the cells from the external connections. The protection may be as simple as a pair of charge and discharge Field Effect Transistors (FETs) with voltage and current detectors, or as complicated as adding firmware controlled fuel gauging and secondary protection.

We're very proud to report that our product webinar, Lithium Battery Regulations and How They Affect OEMs, had the most viewer responses ever for a webinar hosted here at Epec! Over 300 registered for the event, confirming that these latest changes to shipping lithium battery are of real concern amongst some of the industry’s leading Original Equipment Manufacturers (OEMs).

Over the past several years, shipping lithium batteries via air freight has been serious business and it requires significant investment from any company who manufacturer custom battery packs.  Not only do companies need to make sure that battery packs are shipped properly without delays, but also for the safety of the public.  As of April 1, 2016 international regulations applicable to air shipments of lithium batteries have changed yet again and will require that all companies that manufacture and ship batteries continue to invest to stay ahead of the requirements.

At Epec, we are in a unique position of having the capabilities to produce domestically at our Colorado tech center, our Massachusetts assembly facility, or your partner factories in Asia. This allows us both flexibility and control on prototype development, regulatory builds, pilot ruins, and production quantities.

In today's battery and charger market, most companies typically provide either battery pack assemblies or battery pack chargers, as opposed to providing both. In the past, buying a battery from one source and a charger from another worked just fine when using the older NiCd batteries with overnight chargers. However, due to new battery chemistries and the increasing need for faster charge times, careful matching of the charger to the battery has become essential. Without proper battery and charger matching, aspects such as safety, cycle life, and run-time may be greatly affected.

When you consider and evaluate the true stresses that lithium batteries encounter, most battery packs are designed to last three to five years if used and stored properly. Environmental conditions, not just charge cycling, are the key factors for longevity. The worst situation is keeping a fully charged battery at elevated temperatures. When not in use, batteries must be stored in a cool place.

There are several factors to consider when selecting the type of battery cell to use in your battery pack design. Looking at the battery requirements and the dimensional space available are important. Another factor that comes up is pricing. The top tier manufacturer brands can be expensive, but there are also comparable solutions in Asia that will reduce the cost.

The shelf life of a rechargeable nickel metal hydride (NiMH) battery will vary depending on the storage temperature and the size of any attached load. The battery shelf life will also vary by manufacturer. Panasonic recommends the following for their NiMH battery cells.

Determining the cost of a battery pack with fuel gauge technology will vary depending on the accuracy of the battery fuel gauge required. The overall size of the battery pack will also have an effect on the final cost. For example, if a high-accuracy gauge is required on a small multi-cell battery, it could potentially double the cost. The good news is that the cost of battery cells become relatively small when factoring in the added value received from implementing a fuel gauge.