My dad has an electric leaf blower with a huge 56V battery pack. It broke so he let me dismantle it and salvage the Li-ion batteries inside. There were 16 18650 cells I got, but the voltage on all of them were about 1V. They had been critically overdrawn. I really want to keep these since they are high quality and worth like $80. I read a bunch of stuff online about recharging these guys and I've seen a ton of different answers.
Some answers say that it can be extremely dangerous and to just buy new ones. Other answers talk about boosting it for recharging like there's no risk in it. Some answers say if they have been depleted recently then it should be fine (mine are also recent). Some answers say if the battery is low quality, then don't do it (mine are high quality). One answer which I found particularly interesting is that charging it slowly at <100 mA which "will reform the chemistry on the plates, but if you charge too fast it will cause uneven forming of the plates and WILL cause dendrites." which are dangerous. I don't know what is true and what is not. Can I have some clarification?
Although this last answer has unknown credibility, I like that it had a chemical explanation of the dangers. So, can I recharge them at low current? I plan on using a charging module with 1 A max draw, but connected to all batteries in parallel, so the current is distributed and <100 mA per cell. I am also going to closely monitor them with an IR thermometer to make sure nothing gets too hot.