E300 electric scooter battery,

Well how long between runs and stops? Batteries can be bad even with 12+ volts on a meter with no load. Is the on/off regular like the controller cycling, or irregular like a damaged wire? The hall sensor in your throttle could be causing it, if it's loose or not working properly. You can open the throttle with a socket and a screwdriver. Check all wiring, check the batteries under load. If you say more about the frequency and duration of the stops and run periods it would help.

not exact, to charge apropiate needs 10% more than nominal voltage. if not, will not charge the batteries.
And the charger its very important because you can over charge the battery.An example,if you have a 12 Amps Batteries each one if you put it in series will be 24 Volts.at parallel conection will be 12 volts but the double of Amps.
At serial connection will be 12 Volts the amps will be the same but the volts will be 24.

The charger at 12 Volts must be 13.8-14.5 DC Volts and divide the Amps in Hours.
The charger at 24 Volts must be 26-28 Volts. to charge well.

The charger for 12 amps batt example must charge 2 amps per hour at 6 hours = 12 Amps.(2 Amps Charger by 6 Hours Charging= 12 Amps.(Fully Charged.
3 Amperes Charger needs 4 Hours to charge 12 amps Batt.
5 Amperes Charger needs 2 Hours charging an a quarter
All of this is at DC Current.

Luck.

Need model and manufacturer details please?

No. We get batteries from a local supplier and they work just as well. are by far the most common problem with razors because people dont keep them charged.

black is negative, red is positive to controller, yellow is ignition on

i'm having the same problem. checked fuses and both are good. going through the wiring harness to look for shorts. have a bad feeling the micro controller died, that is the little plastic box with metal fins on it under the seat post behind the batteries ******* to the frame. i can bypass the micro-controller and connect one 12 volt battery directly to motor and runs full speed. somehow it is wired with 2 - 12 volt batteries in series to give 24 volts and them the processor cuts back down to 12 volts to run the motor. not sure why this is engineered this way? still working the problem. what sucks so far is that the micro controller is encased in resin so it is virtually non repairable.
* Update added.
Found these wiring harness for sale online scooter stores and on ebay. I replaced mine with some intermediate level adapting the harness to my model scooter and this includes some soldering and wire splicing changing power connector heads off old harnedd to new harness to fit bike. Works great.

The Razor E300 electric scooters are battery operated scooters and can run at 15 miles per hour. This is enough to produce the best fun for kids while on their free time. It's a quiet worker, and with that speed, you won't get scared of the child going too fast to be prone to accident. Yet, it is still good to take precautions. Let the kid wear a helmet, foremost, because this can protect the head should accidents happen.

Your scooter may need new batteries, or a controller. To check these components functionality you will need a volt meter. Check the current coming out of the batteries, check the current going into the batteries and both should read in the 12.5-14 volt range. If your charger, ore the charger connection is faulty you will need wiring, or a charge port. If your batteries are faulty, you will need batteries. Check your controller with a volt meter, or a test light to see that all connections are secure and the controller is functioning properly. If you need parts or repairs done, you can visit this Electric Scooters Parts Store Online with "Find a Repair Shop" feature.

I hope this helps; remember to rate this answer.

I just did mine. You have to replace it with "2" 12volt 7ah batteries. They do cell a harness kit if you do not know how to soder it. I just spent 93.00 to have a motorcycle/off road shop do mine.

Hi. What size batteries you buy will be limited to the amount of room you have in the machine.
17 amp hour batteries are really a bit small for any mobility equipement. A lot of power chairs have 35 or 40 amp/hour batteries.
Buy the biggest that will fit into the available space.
Batteries are designed to perform a certain number of "charge cycles". If you run your batteries down by 75%, you will only get a small number of "charge cycles". If you only use 25% of the batteries capacity, you will get 100's of "charge cycles".
The best I have seen is 7 years out of a set of batteries. Short trips and recharging after each trip is the reason.
Good luck. Neil.

Hi there,

Your scooter uses dual 12-volt, 10-amp hour sealed recyclable lead acid battery.

You may want to open below link to see some examples of batteries suitable to your scooter.

http://www.batteriesplus.com/products/78-0/6069-Electric-Bike-Scooter-Battery/252604-Schwinn/S180-Electric-Scooter/1.aspx

Regards,
Jeep Brainy