by Kevin Parmenter, Chair, and James Spangler, Co-chair, PSMA Safety and Compliance Committee , How2Power Today, Nov 15 2019
Focus:
Various rechargeable battery chemistries have been developed over the years including
sealed lead acid (SLA), NiCd, NiMH, Li-ion, Li-ion polymer and lithium iron phosphate
(LFP or LiFePO4). The different chemistries have their advantages and disadvantages,
but all have safety issues related to charging. This article discusses the risks to
battery safety and long operating life posed by charging errors, and describes the
techniques used in charger design to prevent these errors. It also identifies some
governing standards such as UL 1236 and DoE rules. This information may be of value to
those designing battery chargers as well as those specifying/purchasing them. This
discussion focuses on charging of the SLA and LFP batteries, but these issues
generally apply to the other chemistries too. In addition to some battery history,
topics covered include protection against reverse battery polarity using circuit
breaker, fuse or relay, and polarized connectors; temperature limits for charging; the
constant-current constant-voltage charging algorithm and end-of-charge limits; and why
SLA and LFP don’t tolerate overcharging.
What you’ll learn:
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