Panasonic cf-48 battery issue

Hi, I have a panasonic cf 48 I bought it used it has xp home on it. I bought a battery from ebay new and it charged fine the first day and when I went to charge it again it won't take a charge. I sent it back and they sent me a second battery and the same thing happened. Could something be wrong with the laptop that causes this or is it more likly that the batteries are just poor quailty and cheap? How could I test the battery to see if the battery is good or not? Bubba

 

Its highly unlikely they would have sent you two duff batteries,you will need a multimeter first test the voltage on the battery,if the battery has multiple pins put one probe on one furthest to the left or right then move along the pins until you get a voltage reading,it should be equal to or slightly higher than the voltage written on the side of the battery.

Now switch your multimeter to amperage test,"this test can damage both your battery and blow the fuse in your test meter" now VERY quickly touch the probes on the connectors that gave you the voltage reading,the amperage should spike really high past up towards 10amps and if you have a 20 amp testmeter up towards 20 amps it depends how long you hold the probes on,your just checking that the battery can provide a burst current so quickly remove the probes after a fraction of a second ,if the amperage stops before it maxes out your testmeter at say 1-2 amps then the battery is probably broken as even when the laptop says the battery is completely discharged it should still be able to provide a high burst current.

Do the same test with your power supply,check the voltage then the amperage,the voltage from your power supply will be one or two volts higher than your battery voltage,if its lower you need a new power supply,the amperage should jump up towards 10 amps but will probably stop much lower as it can only provide a small burst current.

Again don't hold the probes on your power supply too long as in essence what your doing by checking the amperage this way is short circuiting the battery and power supply.

If your battery only has two connectors and your power supply only has two connectors you can try charging your battery and test your battery is taking a charge,connect the positive from the battery and the positive from the power supply with a piece of wire and tape it on,now with the multimeter set on amps touch your multimeter probes onto the negative from the battery and the negative from the battery and hold them there or tape them there,the battery should start by first taking one or two amps or more then after a few minutes or hours the battery will be charged and the current reading will be almost zero.

Now put the battery back in your laptop and it should work fine,if it does you can be sure the charging circuits are blown on your laptop.

Let me know if you get stuck or are having trouble...

 

WOW, thats alot of info, Thanks so much. Its midnight and just got home, so I will be testing this first thing in the morning. I would do it now but if I make to much noise it will wake up the dogs and then the wife and I'll be in the dog house, LOL.

 

I havn't got to it yet. I was just wondering if it works fine and its the charging circuits that are blown is that a simple problem to fix? Bubba

 

No its the worst problem regarding a laptop and its almost impossible to diagnose the component on the motherboard that's broken as you would need all the design specs of the motherboard and the data sheets to each component,it usually means you need to replace the motherboard which is the biggest job you can do to a laptop and its expensive,some places will fix the motherboard I've heard of them but never used them as they will charge you about the same price as the laptop cost,even manufacturers don't fix laptop motherboard problems they just replace the motherboard as its cheaper 'but not by much'

If the laptop has never worked since you bought it may be you have bought a lemon,sorryI'm assuming you can still operate it using the power supply cable so its not all bad?

 

I've checked the battery, it has .195 dc and hooked up the wires to it and after two hours it went up to .578. Looks like it was taking a charge. On this battery you have on the left one spot for pos. and then on the left five spots for neg. all of the five spots show current and I just hooked up one of the wires to the middle and then to the pos. Should I leave it on longer or do you think that two hours should have charged it more. Bubba

 

Almost forgot It works fine on power supply. I guess I need an inverter in my truck, do you know any thats good. Do you need to unplug them when starting the truck or just leave them in all of the time. I would like to mount it in. Bubba

 

Unplug whilst starting, just to be on the safe side. If I were you I would add in a fuse between the cigarette lighter and the inverter just to be on the safe side.

 

Right .195 to me means 0.195 V which is nothing as does 0.578 V,even if the battery wasn't taking a charge it should be higher than that,lithium batteries never drop below their working voltage which is around 3V per cell if they do drop below that they become UNCHARGABLE,can you confirm the battery is lithium?

Its hard for me to know what's going on with your battery without looking at it as they are all different even when they're the same manufacturer that's why I said if it has two wires you could have a go at charging it,if the polarity of the battery terminals are marked + and - and you've tried each combination on all terminals and none of them read above .568 volts then I'd have to conclude the battery is dead.

The only other conclusion I can come up with is that the protection circuits on either the laptop or the battery have become so damaged they have completely drained the battery of current,this is pretty unlikely as both the laptop and the battery circuits would have to break simultaneously,it could be the laptop is breaking the batteries as you used them.

From what you have told me I would say they have actually sent you two bad batteries,I would buy a battery from a different supplier and test the voltages before and after use.

EDIT can you double check you have your testmeter set to +10v DC or similar,I just realised I've never seen a testmeter that reads to three decimal points unless set to below 10vcd.

 

Thanks for everyones help. We fixed it by accident By taken it out and putting it back in checking it repeatly. I noticed that the battery was loose in the compartment. The prongs were not in good connection with the laptop. I took a piece of cardboard and folded it a couple of times and wedged it in to make the battery fit tightly. I charged it for a couple of hours and for the first time I could unplug the ac cord and turn it on using the battery power. I fully charged the battery and it lasted for over three hours with some light use. Thanks again for everyones advise and help, Bubba