VS - Electrical Systems From Stop-Start to Hybridization

25

To new battery types & classification

Repeated stopping and starting phases require an adapted battery which can support number of cycles. The battery has to withstand much more cycling: ●● Discharge during STOP phase ●● Discharge during re-crank in START phase ●● Recharge while driving New technologies for new applications While SLI batteries are still massively used for conventional applications, Micro-Hybrid Stop-Start applications require higher performance batteries. The automotive lead acid battery offer is today segmented in SLI (Starting-Lighting-Ignition), EFB (Enhanced Flooded ) and AGM (Absorbent Glass Mat ) batteries.

●● EFB complies with Micro-Hybrid basic demands ●● AGM complies with Micro-Hybrid higher demands EFB batteries feature a flooded battery design with an increased ability to accept cyclic charge current. AGM batteries are valve-regulated lead-based batteries (VRLA), they are characterised by closed cells and an immobilised electrolyte. The performance of AGM batteries makes them a technology of choice for applications with deeper cycling duty. Though SLI batteries have much lower cycling performances, they are still good candidates in Stop- Start applications as auxiliary energy source to secure some voltage sensitive systems in the vehicle. Complementary to their charge and discharge ability, battery technologies differ in their electrolyte stratification level.

-Free flowing electrolyte -For conventional applications SLI S tarting L ighting I gnition Conventional Flooded Battery

EFB E nhanced F looded B attery

AGM A bsorbent G lass M at

-Free flowing electrolyte -Improved cycling Performance -For Start-Stop applications

-Immobilized electrolyte -Very high cycling Performance -For advanced Start-Stop applications

Stop-Start ability

No

Cold Cranking ability (2)

CCA100%

CCA 115%

CCA 135%

Cycling endurance (1) Deep discharge compliance (1) Electrolite stratification Engine OFF periods State of Charge predictability (3) Charge acceptance

Yes

Yes but limited

No

Conventional use

Energy recuperation

No

(1) compared to conventional flooded batteries (2) compared to conventianal flooded batteries with the same case size (3) Affected by electrolyte stratification

64

Lead acid batteries charge and discharge ability.