01 Feb 2019
More than ever, batteries need to be fit for purpose to avoid costly vehicle downtime – Part 2
Last month, John Bentley, technical manager for ECOBAT Battery Technologies (EBT), formally Manbat, began a series of features considering the knock-on effects of vehicle development on CV batteries, particularly in relation to their change of location with the introduction of AdBlue systems.
“Traditionally, lorry batteries have been situated along the length of the vehicle, generally under the driver’s door, but these legal changes which have resulted in the introduction of EGR (exhaust gas recirculation) and SGR (selective catalytic reduction) systems, require the injection of a substance such as AdBlue. This needs to be held in a suitably sized tank, with a convenient location, such as under the drive’s door, which has therefore forced VMs to relocate the batteries from this position.”
“The solution for most VMs has been to opt for end of frame mounting, which locates the batteries across the vehicle, generally under the ‘fifth-wheel’. However, this resolution has had two unforeseen repercussions. The first is a significant increase in the level of vibration, particularly when hitching and unhitching a trailer, and the second, a far higher likelihood of acid stratiphication caused by a decrease in un-homogenised electrolyte.
“In order for a lead acid battery to operate efficiently, the electrolyte, which is 65% water and 35% acid, must be 100% homogenised from the top of the plate to the bottom. With batteries mounted along the length of a vehicle, the electrolyte is kept well-mixed by the natural acceleration and deceleration of the vehicle during its day-to-day use, which, in effect, stops the acid sinking. By contrast, batteries mounted across the vehicle do not benefit from this process, which means the acid, the heaviest element, tends to separate and drop to the bottom of the cells.
“This has an adverse effect on the battery’s ability to charge, as it can’t charge in concentrated acid and is less efficient in the dilute. In addition, the concentration of acid will cause the lead plates to sulphate from the bottom, commonly known as bottom plate sulphation, and become brittle, which left unchecked, will result in the battery losing a third of its capacity in as little as six months and contribute to its premature end of life.”
To find out how this issue has been overcome, look out for next month’s email and EBT’s continuing story.
For further details, please contact ECOBAT Battery Technologies on: 01743 218500 or visit: www.ecobat.tech