Something in my bike (USB Charger, Hella Socket itself) has made a short circuit leading to deep discharge of Lead-Acid battery.
Battery was down to 5.2V for time counted in minutes. I've disconnected load sources and recharged the battery using recovery function.
Now battery keeps at quite rock-solid 12.6-12.4V, but I'm wondering how much damage this undervoltage could made? Was there enough time to create thick Sulfur coating on electrodes?
Your battery has most likely lost some capacity. If this is a "car" battery, then it is probably significantly damaged. If it is a industrial battery with "deep cycle" capability, then it should be less damaged.
Read the datasheet. If this is a consumer item that doesn't have a datasheet, assume significant damage.
When a battery sits for a length of time in a discharged state that's when the plates will suffer the most damage, the lower the voltage the worse it gets of course. if the discharge is very brief and is promptly recharged, then damage will be minimized or avoided. Keeping a battery on a float charger when it is very rarely used is a good way to keep it from deteriorating. I still try a high frequency pulse charger in the hope that it will bring back a weak battery, but I have not experienced any real positive results with this.
