Does this ground connection seem to be ok/clean enough or does it look like it could be causing issues.
Cars been running seemingly weak for a while and still is however during this period all the mechanics I showed it to never said anything about the ground so Iβm assuming even if this is not the cause, my problem will still be there, but you never know. Btw some of that white stuff could be baking soda that dropped on there:
To answer your question, yes, that is corrosion and it can cause issues with starting/charging, and possibly even with your audio equipment if there's not enough ground for it to work right. The corrosion (white stuff) causes resistance to the flow of electricity, thus causing the issue.
You need to get rid of this. While not completely necessary, my suggestion is to replace the cable. Why? Because the corrosion will trace up into the wire and will cause resistance as well as it will continue to allow the corrosion to continue. Baking soda and water can only do so much. The cable should not be overly expensive to replace, especially considering how short it is. You could even get an aftermarket one which would be less than what you'd pay at Honda. You may or may not need to replace it, but considering how it looks, I'd highly suggest it.
If you go the route of replacement, you will want to completely clean the area. This is when the baking soda and water will come into play, as you want to arrest any of the corrosion which is there. If you find bare metal beyond where the end of the negative cable is to go, then you'll want to throw some paint on there to help prevent corrosion in the future.
A solution of baking soda and warm water will dissolve dried battery acid, vented from batteries and depositing around the battery. Battery positive seems to collect acid venting more than battery negative, drying out and leaving a bluish white powdery deposit. When baking soda/water comes into contact with dried battery acid, bubbling is immediate to dissolve and neutralize it. Water rinse. You can try dribbling warm/hot water on the chassis ground connection to see if bubbling occurs immediately otherwise it might be wise to wire brush as much deposits before removing the hold down nut for further cleaning. Wire brush all corrosion, reassemble and ensure a clean tight connection. Coat with grease. The battery cable appears clean with oxidation on bare wires. Coat this with grease and the terminal connection to battery.
Find the engine ground connection and check it for similar corrosion. Two main grounds; chassis and engine for all electrical/electronic connections.
If your car is running weak that probably has nothing to do with the battery or its connections. Once the engine has started, power to run the car (and recharge the battery) will come from the alternator. If the starting is weak, that could be a problem with the battery or its connections.
That connection looks pretty corroded. But the best way to be sure if the resistance is excessive is to measure the voltage. With the engine off and a decent electric load (headlights, cabin heater, windscreen heater) on, current will flow from the battery but there should be no measurable voltage between the chassis and the negative battery terminal.
Similarly with these loads off and the engine running the alternator will send charging current to the battery but there should be no measurable voltage difference between the chassis and the negative battery terminal. As an additional test or if you don't have a voltmeter, you can use a jump lead to connect the engine block to the negative battery terminal. If there is any change in engine sound (indicating a change in charging current and hence engine load) it means the ground connection is poor and some of the charging current is going through the jump lead to bypass it.
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I had a problem with starting a few years back. As soon as the solenoid kicked in the instruments would go dark, and the solenoid disengaged. Then the cycle repeated once a second. Battery voltage was fine, even with the headlights on. However at one point when I touched the negative terminal with a single meter probe, a spark flew out! I knew I had found the problem. There was clearly a voltage difference between the battery post and the clamp.
I actually measured 6 volts between the battery post and the clamp with the headlights on. So I removed the clamp, cleaned it and reassembled it. Problem solved.
