Lead-acid chemistries prefer light cycling and full recharge between those cycles. Lead-acid batteries are traditional cycled to 50% depth of discharge because it offers a balance between duty life (years between failure) and bank size.1) Pulling the bank below 50% DoD in emergnecies will not automatically cause damage assuming a full charge is accomplished ASAP.
This article is about the intentional severe use of lead-acid banks by running them below the 50% mark, followed by vigorous recharging at maximal voltage.2). Perhaps forgoing Float altogether. This might be desirable when:
For folks willing to trade battery longevity for some amount of increased capacity, common low-end targets for low voltage disconnect are: