For how long do you charge a 9.6V NiMH Battery Pack 700 mAh? It says don't overcharge, but can't find any info to instruct what overcharging is!! It goes to a remote control car made by Maisto. It is a 1967 Ford Mustang GT - Pro Rodz.Can't find the correct category below so picked a Maisto product just so the question would post!

Must be the regulator either fried ,wrong or wired up wrong its the only thing that can do that job

You cannot over charge a battery pack as the charger stops at full charge. However by recharging a partially used battery pack you can develop a memory in the pack that the charger will not charge past

Yes you can overcharge a battery, it all depends on the charger your using. Most chargers are single stage chargers. Most scooters come with a single stage charger. My scooter has a built in single stage charger What this type of charger does is output a constant 24v @ 4amps.The problem is batteries amperage requirements decrease as the battery charges. An overcharge will occur when the battery is charged. It requires very little amperage to maintain a charge on a fully charged battery. A single stage charger like mine will output 4amps regardless of the state of charge of the battery. Batteries bring charged with single stage chargers loose their electrolyte. What happens is overcharged batteries break down the electrolyte into oxygen and hydrogen. So overcharging will cause a battery to "boil-out" its electrolyte. Batteries don't work without electrolyte. In the old days there were only single stage chargers. That was the state of the art back then. So to cope with the constant overcharging batteries had refill ports where you could replenish the electrolyte using distilled water.

Scooter batteries are far and away different from the lead acid of the 1970's. Scooter batteries are sealed, they are deep cycle, they use a glass mat soaked in gelled electrolyte. These glass mat batteries optimize the electrolyte used so they can use allot less of it. These newer batteries have a lot more power in a lot smaller package but they have a draw back, they must be charged properly. You can absolutely can not charge these batteries with a single stage charger. Actually you can charge with this device but you will loosed electrolyte each time you charge.

I use a three stage charger 24v @ 5amp. This charger s different from a single stage. Its what they term a "smart charger" it monitors the state of charge of the battery. As the battery charges it turns down the amperage. When the battery is fully charged the amperage is turned low enough were the charge is maintained. The entire charging process is designed to preserve electrolyte. In short this type charger will not overcharge the battery.

Click here to see the charger i currently use.
http://www.amazon.com/Sealed-Battery-Charger-3-Stage-Fan-Cooled/dp/B0051WHAU0

Over charging could be the result of several things including:

Faulty Voltage Regulator
1. A car's battery will overcharge if the voltage regulator isn't working correctly. A voltage regulator is usually part of the alternator, and is used to keep a steady flow of voltage to the battery. If the voltage regulator is defective, it will send either too little or too much charge to the battery. If it sends too much, the car battery will overcharge. The voltage regulator is easily replaceable at an easily affordable price, sometimes for as little as twenty dollars, as of 2009.
Faulty Alternator
2. Sometimes the alternator itself can be at fault. The alternator is the device that converts the mechanical power of the engine into electrical power to charge the battery. When an alternator breaks, it usually stops creating electricity for the battery, which will then eventually die. However, if the wrong alternator is placed in the car, or if the alternator is running at the wrong pace, it will create too much energy for the car battery, causing it to overcharge. The alternator is another easily replaced part.
Incorrect Charger Use
3. If a battery charger is used to charge your battery outside of your car, improper use of the charger can result in overcharging. If a battery is placed on the charger too long, it can result in overcharging, and a significant decrease in your battery's lifespan and efficiency. This is why it is important to read about your specific battery and understand how long it needs to charge to be effective. Too much charge will lead to problems.
Faulty Battery Chargers
4. Sometimes chargers can be faulty. Their settings may be wired incorrectly, or the charges labeled incorrectly. As a result, your battery may be getting overcharged, even if you are carefully monitoring your charging. This is a problem that is hard to avoid, as manufacturing mistakes can happen anywhere, anytime without warning. It is a good idea to test your charger regularly to see if it is running correctly.
Heat
5. Extreme heat in the summer can also have an adverse effect on the car battery. If the battery has been previously overcharged, extreme heat can increase the problems caused by overcharging, and exacerbate any other problems with the battery. This problem can be hard to avoid if you live in a warm climate. The only real way to ensure safety against this problem is to avoid overcharge in the first place.

It could be possible that 1 of your 2300 mAh AA battery is defective.
Try to charge only 2 2300 mAh batteries at a time to see if it can charge.

I have a lot of old 45-40 Series Metz 45 NiCd battery packs, that I will eventually rebuild with new NiCd batteries. I got them from Photographic Trader magazine and from ebay. I've heard that NiCd cells are going out of production, in favour of NiMH cells. I've found it's easier to put NiCd or NiMH cells in the alkaline battery holder, the flash recycle time is only slightly longer. I charge them separately out of the holder, or in the holder with a connector I made. NiMH cells need a suitable charger, with peak detection, as NiMH cells don't like being overcharged.

ULTRALAST UNIDEN FRS RADIO BATTERY
RECHARGEABLE 4.8V 700 MAH NIMH
[ULBP-38]

$8.97

Available from Thomas Distributing

http://www.thomasdistributing.com/shop/ultralast-uniden-frs-radio-batterybrrechargeable-48v-700-mah-nimh-p-1654.html?SP_id=&osCsid=a98rm8a91donrsllit8gi3gna7

you should purchase a mobile v3 car charger for the phone and do not use the other one you have

Yes. But a proper charger will not do that.