My batterys dont charge after a long run or short i hasve to recharge them to start the car i have checked them with a batterys tester and they are ok but something is drainning them or not charging them when i drive my car please help i have a multi meter and am a electrician by trade my car is a pajero 2.6 turpo intercooler 1986

Do yourself a favor an take it to a qualified repair shop. Charging system is computer controlled , if you have been to school for this ,you have no business messing with it .

Test battery with load tester. Check for electrical short.

take your battery to a parts store. they will test it. It is probably shorting out inside and causing the loss. buy new battery.

Check battery cables are correct ! Prime suspect here ! Alternator may be damaged and shorting .. Don't drive any car that will melt jumper cables ! Something very basic wrong here.

Its ether the battery or the alternator. The best way to check it is with a load tester. To check it hook the tester to your battery with your car running, red to positive (+) black to negative (-) if the alt. Is good it should read around 13.6 volts to check your battery shut off your car and toggle the load test switch hold for a 10caribbean count the meter on the tester will tell you if its good. If you don't have one or can't get one most parts stores. Will do it for free. If both check out good you have a dead short somewhere. In that case you just have to track it down. But start with battery or alt.

If this is a new Battery or a good Battery, then it could be a bad alternator. Or it could be as simple as a loose or corroded connection(s).
It could be a bad battery. One way to find out is to use a Battery Tester. Most auto parts stores will check your Battery for free. You can also buy a Float Ball Battery Tester for about $1.50 at most stores.
Charge the Battery overnight with an electrical trickle charger. Make sure the Negative and Positive Cables have been removed completely from the Battery and not touching the post during the recharging process.
Clean the Battery Post and the Connectors with a Battery Brush available for about $2.00. All metal should be nice and shiney!
After an overnight charge: you can use your Float Bulb Battery Tester. Remove the Battery Caps and check each individual cell (hole). More than two bad cells in a Battery = a new Battery. Be careful as the Battery contains ACID.
Reconnect the Battery and Start the Van.
When the Van has Started - Keep the Engine running and Remove the Negative Cable from the Battery.
If the Engine dies, it is the Alternator that is bad and needs to be replaced.
Let me know if this helped, or if you have additional information or questions. Feel free to contact me at FixYa.com!

This sounds like a charging issue linked to the alternator. If you can start the car you can have it tested while running with a clamp on electrical system tester at a service center. Before doing so clean and inspect all battery cable and ground connections.
A bad battery will fail to hold a charge or recharge, but once the car runs on the alternator,after starting so if it starts and doesn't perform right, most often the cause will be the alternator

It sounds like the Alternator is actually bad.
One great way to determine this:
Recharge the new battery with a trickle charge overnight. Make sure use remove the wires going to the Battery before recharging.
Replace the Battery Wires.
Get the Vehicle Started.
When it has Started: Leave it Running and Disconnect and Remove the Negative side of the Battery. If the Vehicle dies, it is the Alternator that is bad, and needs to be replaced..
The Battery starts that vehicle, and provides nominal power to certain accessories. The Alternator actual Runs the Engine and Recharges the Battery with a low trickled charge.

Answering your questions in order:

1. No, there's no such device to prevent the car from starting; a battery that requires a jump start would require more than 5 minutes running time to recharge. The battery needs to be charged to work again, (unless it has a dead cell, inexpensive battery testers will confirm). A jump start is still possible but wouild require leaving the jumper cables on for at least 15-30 minutes to provide enough of a charge to start the Rav again. Charging on a battery charger is preferable.
2. Yes; short trips and lack of use will kill a battery over time.
3. Yes; Here is a link to the basics of checking a charging system http://www.aa1car.com/library/charging_checks.htm

In summary, most should get more than 3 years out of their battery. You've already determined that the acid levels in the battery are good (most don't even check for fluid levels). Constant charging and discharging will kill a battery and this isn't apparent in your case.
If a battery charger isn't handy, try hooking up the jumper cables and leave the other car running for at least 15 minutes. I hope this answers your questions. Best of luck.
Greg

What initiated the need for jump starting? Is the alternator charging? Has the battery been checked?

To check the alternator, once the engine has been jumped and is running, remove one of the battery post connections. If the engine dies, the alternator is not charging the battery, and the symptoms you describe are the on-board computer going through low voltage spasms until sufficient electrical power to operate the engine / tranny is drained and the car dies.

If the car continues to run with no battery attached, the alternator is charging - - - and I would recommend removing the battery and having it checked and (if good) recharged to full capacity. I would also recommend having it charged even if the alternator is the problem just to delay the onset of the low voltage problems. The car should operate normally for a few miles before the battery drains too low after a full recharge, enabling you to get it to a shop for alternator service / replacement.

If you attempt replacing the alternator yourself, make sure the battery is disconnected prior to starting the job. Saves blowing up good stuff by accidental short.

Hope this helps and good luck!

-WB.