Yes, low amperage can potentially damage an electric car battery by causing sulfation, reducing capacity, and shortening lifespan. How Does Amperage Affect Car Battery?.
Short circuiting a battery means excessive current follows an unintended path, due to an abnormal connection with little or no impedance. This condition allows an excessively high current to flow with little resistance. An uncontrolled surge of energy can damage the circuit, and result in overheating, skin burns, fire, and even explosion.
You can always charge a battery with less current. Heck you can even not charge it (no current). But if the battery wants to charge with more current than the adapter can handle, the adapter might overload. If it's a good adapter it will just switch off. If it's a crappy one it might catch fire. So your choice.
Is a low charging current a problem for a lithium ion battery?
Depends on the battery chemistry. For lithium ion, it's usually not a problem and can even be a benefit. For NiMH, a charging current that is too low can make it dificult for the charger to detect the point where the battery is full, which can lead to overcharging and overheating the battery.
Whether or not gas is actually released, damage to the battery WILL occur. What you want to do is, after your cell hits the target voltage, you apply a "float" voltage, just a trickle of current. For a 40 Ah lead acid battery, 750 mA exceeds the self-discharge rate. The 750 mA current will cause the voltage to rise.
For NiMH, a charging current that is too low can make it dificult for the charger to detect the point where the battery is full, which can lead to overcharging and overheating the battery. For questions, news, and discussion about batteries, cells, chargers, charger/inverters, power banks and UPSs.
Electrical Engineering Stack Exchange What if i charge a battery with low ampere.? Assuming we have a mobile-phone LiIon battery and a charger which is only able to supply less ampere than the original one, will it damage the battery if i charge with less ampere charger than the original one.