AVOID LOW-COST LI-ION ‘DROP-IN’ OPTIONS
There are low-cost ‘drop-in’ lithium batteries available with internal disconnects to protect the battery. But these can lead to much larger issues.
These batteries have huge limitations on the current they can deliver or be charged with. They can also cause damage if disconnecting themselves when being charged by an engine alternator. This will opencircuit the alternator and can lead to damage to the alternator and all other connected electrical equipment on the vessel.
The marine electrical regulations have been written to preclude these sorts of issues. Unfortunately, the majority of Li-ion batteries offered in the marine market don’t comply with these standards and at best will provide poor performance. At worse these are dangerous and can cause complications with insurance cover.
SAFETY
Misconceptions around safety issues with Li-ion technology have, in some cases, unfairly damaged their reputation. To set the record straight there are several points to cover.
The first thing to understand is that there are various Li-ion chemistries under the Li-ion umbrella. All have advantages and disadvantages and some are better suited to particular industries.
In the marine industry, Li-ion iron phosphate (LIFEPO4) chemistry is typically used thanks to its chemical stability which ensures high safety standards. Different Li-ion chemistries used in electronic devices, toys and electric vehicles generally place a high value on greater energy density. But the type largely used in marine batteries is extremely safe and considerably more tolerant than other lithium chemistries.
As an example, Juice PRO Series batteries are tested to IEC standards which require them to be subjected to an over-discharge test,a forced discharge test, external short circuit tests, a thermal abuse test, crush test, nail penetration test and drop test. Through every single test the battery cells – while damaged and possibly unusable – did not cause any safety issues.
Based on this, it can be argued that the inherent safety of Li-ion iron phosphate chemistry coupled with a suitably-designed battery management system means that Li-ion batteries could be considered safer than traditional lead-acid batteries.
While the initial outlay for Li-ion (purchase plus installation) is higher than for lead-acid technologies, the performance advantages (more usable energy and much higher cycle life) make Li-ion batteries far less expensive per AH of energy delivered.
Add this to the savings in weight (and associated performance implications), size and better voltage stability and the argument for converting to correctly designed compliant Li-ion batteries stacks up. Basically, if finances allow, make the switch at your next battery change and enjoy the features this technology has to offer.