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defender dinky

low battery

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hi, the wife's p38, everytime we go to start it the battery always seems low on charge, it only has to see the jump leads and away it goes first time, what could it be , it has a heavy duty battery on it or could it be the starter motor which turns very slow, or is it the alternator, how do i check for the right answere, already checked earth leads taken them off and cleaned them, thanks for any help in advance, dd

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Well, in 70% of all cases the battery has a defect (one cell damaged, insufficient fluid, or just old\worn). If it starts by jumpstarting on the battery terminals it is unlikely that a connection is bad.

Check the battery voltage in the morning and after a drive. With the engine not running ist should be well above 12 volts (12.2-12.6) for a healthy battery. To check the alternator, the voltage should come up to 13.8v with the engine running.

There is still the chance of discharge whilst standing and you could measure that by checking the current in line with the battery terminals. However if your multimeter would be ok to do so, but you are not entirely sure how to measure the current please ask. You wouldnt be the only one who has transformed his multimeter to ash by doing it wrong, and this includes myself.

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Well, in 70% of all cases the battery has a defect (one cell damaged, insufficient fluid, or just old\worn). If it starts by jumpstarting on the battery terminals it is unlikely that a connection is bad.

Check the battery voltage in the morning and after a drive. With the engine not running ist should be well above 12 volts (12.2-12.6) for a healthy battery. To check the alternator, the voltage should come up to 13.8v with the engine running.

There is still the chance of discharge whilst standing and you could measure that by checking the current in line with the battery terminals. However if your multimeter would be ok to do so, but you are not entirely sure how to measure the current please ask. You wouldnt be the only one who has transformed his multimeter to ash by doing it wrong, and this includes myself.

hi, well to be honest i have never used a multimeter, so yes i would be looking for advice how to use it properly. ;):D cheer's defender dinky

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oops, Just saw that it's a P38 you are talking about. Measuring the current would require to disconnect one of the battery poles and that comes with a whole procedure in a P38 due to the alarm system.

I don't have particular experience with that procedure and I therfore step back and would ask some p38 experts to describe how this can be done properly.

I would start with simple measurement of voltage between the battery pole. this, at least, would give you an indication of a possible problem.

...if you have never used a multimeter you probably might not have one and it could be the easier way to get the battery checked in a garage.

if you have one, set it on 20V DC and connect the test tips to the battery pole after a longer drive (no ignition) in the morning (no ignition) and with the engine running, and report the readings. we will take it from there then.

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If the battery is low/flat then you need to fully charge it with a battery charger. Don't expect the alternator to do that - they're not actually designed to recharge flat batteries and if you keep asking it to you will need a new alternator as well.

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oops, Just saw that it's a P38 you are talking about. Measuring the current would require to disconnect one of the battery poles and that comes with a whole procedure in a P38 due to the alarm system.

I don't have particular experience with that procedure and I therfore step back and would ask some p38 experts to describe how this can be done properly.

I would start with simple measurement of voltage between the battery pole. this, at least, would give you an indication of a possible problem.

...if you have never used a multimeter you probably might not have one and it could be the easier way to get the battery checked in a garage.

if you have one, set it on 20V DC and connect the test tips to the battery pole after a longer drive (no ignition) in the morning (no ignition) and with the engine running, and report the readings. we will take it from there then.

hi, will have to wait till weekend, son's a sparky he will have one, but still on holiday. cheer's anyway will let you know weekend dd

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If the battery is low/flat then you need to fully charge it with a battery charger. Don't expect the alternator to do that - they're not actually designed to recharge flat batteries and if you keep asking it to you will need a new alternator as well.

A modern electronic charger will charge the battery at a number of charge rates depending on the state of charge. This helps keep the battery in good working condition and allows it to reach it's full charge. On the other hand the alternator is designed to generate a consistant 14.3 volts, not actually the best thing for the battery and it won't help it reach full charge or recover a weak battery.

But if you drive it regulary the alternator should be more than capable of putting sufficient charge in the battery to start it up. If it's not holding charge I'd suggest it's time for a new battery.

To avoid problems with the alarm can you use one of those cigarette lighter power supplies to keep the alarm memory alive?

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Do you have the handbook for the p38, I think it tells you in there how to take a battery off, it's something daft like the key has to be in when you do it. As said above, I would start with voltages, usually all the information you need.

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Forgot to say, using another power source will affect your current reading so use it whilst connecting and disconnecting the ammeter but remove it whilst it's on test

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A bit obvious but have you checked your batter connections? To avoid the battery off issues, next time the battery refuses, tap the terminals with a LIGHT hammer to rotate the terminal on the post (if it has round posts) or up down with rectangular posts.

I have fitted a female kettle type plug lead across the terminals of all my cars, the matching computer plug is fitted on my Halfords maintenance charger instead of croc clips (the car's lead is coiled up next to the battery when not in use.) If the car is standing long I just pop the bonnet pull out the lead and join up the connectors then I can drop the bonnet with the leads in place without the problem of clips popping off or contacting the bonnet. Now it's a doddle to keep the battery charged and no excuse to do it tomorrow. The lead is not suitable for high rate charging!!!!!

My series 1 has a built in plug fitted to the seat box with an inline fuse for good measure. The plug came off the back of a dead computer.

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Does sound like a duff battery to me. If it starts of the jump leads and runs fine then the alternator is doing it's job. Even with the healthiest of batteries you wouldn't get far if the alternator wasn't charging (well, you won't with the TD5 so I wouldn't think so with the P38 either). Also you don't say there are other problems such as air suspension not raising etc etc, so again, sounds like the alternator is doing the work.

Most motor or fleet factors who supply batteries would be able to test yours for you for free.

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Does sound like a duff battery to me. If it starts of the jump leads and runs fine then the alternator is doing it's job. Even with the healthiest of batteries you wouldn't get far if the alternator wasn't charging (well, you won't with the TD5 so I wouldn't think so with the P38 either). Also you don't say there are other problems such as air suspension not raising etc etc, so again, sounds like the alternator is doing the work.

Most motor or fleet factors who supply batteries would be able to test yours for you for free.

hi, asked the wife if everything works ok, she said yes except for passenager side window gets jammed halfway down, i had a look took door panel off tried window and yes it got jammed halfway,what i did notice was that the galv plate i think motor is fix to, is bent up when operating the window, looks to me a bolt or rivet is missing that hold the plate in position, could it be a live wire has been servere and touching the car body,reason why i think this is because i charge a battery today fully, she just gone out and wouldn't start again had to jump it, now jump leads from donor veichle 1 to positive and 1 on a good earth such as engine mount tried to start her up and WOW sparks flashes mega time, doe's this tell me that the car body is live somewhere and that's why it's draining the battery, having a look tomorrow to dark, other than that the car runs great, cheer' defender dinky

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well, it could be everything. Including the wire. but if it dicharges that quick we all would hope that the fuse blows. So I'm relatively confident that it's not the wire at the window motor. I would fix it anyway.

How old is the battery?

I still give it at least 70% that the battery is gone. Get it tested in a battery shop for free. takes 5 minutes. The timeloss of having this problem is already worth two batteries.

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I agree, get the window problem sorted anyway, and get the battery checked out. As you said, you charged it and it quickly wouldn't start again, that points to the battery.

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hi, checked battery, alternator, and even the starter motor, with multimeter live to terminal and earth to engine block and they al show 14.2/3, with engine running, cheer's dd

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That's good! Meaning the alternator works perfectly fine.

Another point for the battery being the culprit.

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hi, me again,battery on my d90 starts first click of the key, so exchanged it with the one on the wife's p38,started first time, but so did the d90 with the p38 battery on, i'm waiting now to see if p38 drains my battery, off d90, noticed something today the suspension did'nt rise, have to wait and see now,dd

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hi all, sorry for delay just wanted to give p38 a chance to drain battery,but it's still going on first turn of key :):i-m_so_happy: , fixed window, and also put in a hot start kit on p38, had heavy frost thee other morning and still started first time, and so did d90 with the old p38 battery on, bit baffled to why it all happened,more good news p38 passed mot yesterday one advisery o/s rear brake pad slightly low :P;):):D cheer's defender dinky

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