Originally Posted by
FlyJSH
I'd rather go back to lead acid. NiCads and MiMH can both go into an overcharged/overdrawn/overheated state that can lead to venting or fire. Lead acid generally do not (without actually throwing them into a fire).
Also, the nice thing about lead acid is they tend to fail slowly and have a more measurable output drop (they give warning when they are getting weak while NiCads and NiMHs do not).
If weight, charge time and heavy duty cycle are not an issue then lead acid out performs them all. They, however, take proportionally much longer to charge, quickly fail if deep discharged and weigh 'a ton'.
I do not know how many pounds of Li-Ion batteries are part of the 787 design. Adding a couple of hundred of pounds for another technology would amount to just one more average male passenger.
Whatever Boeing chose as their option it is not just a matter of changing the batteries, all elements relating to the charging circuit and the monitoring thereof need to be changed as well.