My kids have been using this replacement battery for a couple weeks now. It goes in a 2 seater mustang. Total kid weight is 95 pounds and this battery has not blown a fuse yet or had any issues. It is visibly about half the size of the original, but it doesn't seem to impact power or battery life before needing recharge. The car has a 2.5 mph speed setting and a 5 mph speed setting and the battery is fine running on high speed with both of them in the car. They use it in the yard with some slight inclines and on the street during walks which has the battery running for about 30 minutes straight to make it back home.
One thing I don't understand about these batteries is why they don't provide smart chargers with them. I believe that most battery damage or issues come from over-charging or under-charging the battery and using them anyway. Generally people don't want to either wait the estimated time of about 12 hours or they plug it in and forget about it charging it for a couple days. Any reviews stating the battery started smoking, don't charge inside house.. that's likely due to overcharging. Honestly, just do yourself a favor and get a $10 multi meter. They are super handy anyway. I test all batteries using a multi meter; button batteries, AA, AAA, C, D, car batteries.. you name it. That way you don't overcharge rechargeable batteries and don't throw away small batteries that might be good when just one of the batteries in a multi battery device is dead.
If using a multi meter, measure the voltage after the initial 24 hour charge. Write down the measured voltage if needed, that will be your target voltage every time you recharge. This small battery held about 13 volts for me. So depending how much use the battery has gotten, guestimate your charge time. Not every play session will drain a battery 100%, so a full recharge may only take 4 hours instead of 12, hence the common overcharging issues. Use the multi meter to measure the voltage of the battery across the positive and negative leads. Measure the voltage with the charger unplugged from the wall. Doesn't need to be unplugged from the battery, just the wall. At the target voltage stop charging the battery just like a smart charger would. The battery will last much longer and you will start to get a pretty good idea of how long the battery needs to be charged after each use.
Currently the connectors seem very sturdy and secure. I'd guess a long time before they wear out and break. Once you put the connectors on, there is no need to take them off so don't do that. Its likely that constantly connecting and disconnecting the connectors would cause failure pretty quick. Also, as I said, no fuses have blown yet and the battery has been used and charged about 5 times now. But fuses and connectors are cheap to replace if they are damaged at any point - under $5 from auto parts store, maybe even less on Amazon. It's so hard to determine on Amazon if a product is good or not when there is no product without some negative reviews. So we are left guessing was a negative review due to user error or does the product truly have problems? Currently, I highly recommend this replacement battery. Keep it in perspective that it is half the cost of a genuine power wheels battery, so you shouldn't really expect the quality, performance, or ease of use. But this knock off does a nice job of being a replacement if used properly.
Lastly, I will provide updates only if I start having any issues with the battery. So if no update, then the battery is still running great!