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Old 4th June 2020, 20:37   #31
COLVERT
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Analogy for some clarity about battery capacity.

Two tanks of water side by side.
Both a metre in depth.
One tank a metre in diameter and the other ten metres in diameter.
Let the depth be the voltage ( 12 ) and the diameter be the capacity. ( Amps. )

Obviously the larger tank has the greater capacity but the depths ( voltages, are identical. )

It's possible to have two batteries with very similar voltages but, as the tanks described above, to have totally different capacities.

It's the capacity that's needed to do the work.

The starter motor is 12 volts but needs something like 150 amps to spin it. As a battery ages it loses capacity until it reaches the stage where it can't do what you want it to do.





PS. At my age I have intimate understanding of that feeling and it makes my wife very happy to keep telling me so.--

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Old 4th June 2020, 21:58   #32
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Quote:
Originally Posted by Supervinnie40 View Post
... it happened twice that my battery was below 6v ... this happened after only 1.5 weeks after parking the car. I did several longer runs (40km) before that time.
Thanks for this useful information Vinnie. It sounds to me as if your battery's capacity has been severely reduced as Colvert has just described. This has probably resulted from infrequent short journeys (40 km is not really adequate to recharge a depleted battery).

When your battery is unable to turn the starter motor it should take 24 hours or more before your smart charger tells you that it's recharged. If this happens sooner, the battery may be beyond saving.

I think the long term solution to your problems Vinnie is to use your charger more frequently.

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Old 5th June 2020, 04:40   #33
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Quote:
Originally Posted by edwardmk View Post
I had the same problems with my 260 last year. Like you I took many readings and swapped around every fuse I could find. Because my battery was fairly young ( around 10-11 months I seem to recollect) I assumed it was OK. I invested in various pieces of test kit but got mixed results. Finally I gave up and went back to Halfords who were initially doubtful it could be faulty (fairly new battery). Their service guy appeared with a very expensive meter which gave a simple message...'replace battery'. Then they were as good as gold and exchanged it under their 4 year warranty. All my issues disappeared. I now hook up a Ctek 5a charger when it isn't in use for more than a week and it now starts first time (so far lol). Apparently batteries which are fairly new can lose a cell and cause trouble, especially if the battery has been run very flat. SD1 and Colvert were both very helpful at that time too. And it is technically correct that electrons travel from negative to positive.
In my case the battery is only a few months old. And I've dealt with the seller before. They are going to give me a very hard time probably. So, if it doesn't turn out to be a drain, then I'm still out of 100 bucks for a new battery .

Quote:
Originally Posted by vitesse View Post
Your post prompted me to have a look at two of my spare batteries in the garage. I probably last charged them about 2 or 3 months ago on a standard (non-clever) charger. At the time my son-in-law had problems starting but it always started with a freshly charged battery and then eventually wouldn't start at all. But it was the starter solenoid at fault so I kept the batteries charged until I replaced the solenoid which was probably in April. They haven't been charged since.
The Bosch battery read 12.7v / the Tudor just over 13v.

Regards
That worries me. Mine didn't go higher then 12.45. And that was freshly from the charger.

Quote:
Originally Posted by COLVERT View Post
Vinnie.

Item 2/ in my post.

The fact that your charger goes into TRICKLE mode does not, unfortunately, mean your battery is fully charged.

All that charger is telling you is that the part of your battery that is healthy enough to take a charge has been charged.

If your battery is almost at the end of its useful life and the plates are beginning to fail that charger just says---I've done my best with what's left of your battery plates. The resistance they put up when I'm tying to charge them says to me they are fully charged so I relay that message to you. BUT it's very rarely true.---

You could be fighting a losing battle with a battery that's on its last gasp.

Nowadays when the acid in a battery can't be got at to test it the best remaining way is with a garage Drop-Tester.--
I didn't know that. I wronfully assumed that my charger (which was kinda expensive) was clever enough to tell me what was happening. According to the manual it even has a mode in which it says "Err", which means that the battery is absolutely dead. Apparantely mine is only on its way , but not there yet.
Quote:
Originally Posted by COLVERT View Post
Analogy for some clarity about battery capacity.

Two tanks of water side by side.
Both a metre in depth.
One tank a metre in diameter and the other ten metres in diameter.
Let the depth be the voltage ( 12 ) and the diameter be the capacity. ( Amps. )

Obviously the larger tank has the greater capacity but the depths ( voltages, are identical. )

It's possible to have two batteries with very similar voltages but, as the tanks described above, to have totally different capacities.

It's the capacity that's needed to do the work.

The starter motor is 12 volts but needs something like 150 amps to spin it. As a battery ages it loses capacity until it reaches the stage where it can't do what you want it to do.





PS. At my age I have intimate understanding of that feeling and it makes my wife very happy to keep telling me so.--
With my 6 months old battery I didn't really think this would be an issue

Quote:
Originally Posted by SD1too View Post
Thanks for this useful information Vinnie. It sounds to me as if your battery's capacity has been severely reduced as Colvert has just described. This has probably resulted from infrequent short journeys (40 km is not really adequate to recharge a depleted battery).

When your battery is unable to turn the starter motor it should take 24 hours or more before your smart charger tells you that it's recharged. If this happens sooner, the battery may be beyond saving.

I think the long term solution to your problems Vinnie is to use your charger more frequently.

Simon
I should've mentioned that I only once drove the car after a jump start. The other times I took out the charger to fully charge the battery.
In the beginning it could well take 2 days (at least when the sun was shining) to charge the battery. Since then, I have been trying to keep it charged. Getting it from 10 or 11v to 12v only take a couple of hours.


Although I am thankful for the help and assistance, I am also still keeping in the back of my mind that this battery is fairly new. And a new battery shouldn't discharge completely in a week. There is a chance I got a bad one, but I rather double-check it's not just a parasitic drain. I've seen a drain of 0.45 amps on the multimeter earlier last week, and in theorie that should deplete a 100ah battery in about 9.3 days. Which seems fairly plausible considering my own experience.
Take into account that the battery has been almost completely empty a few times (below 6v on the meter), the battery probably lost a fair few of those original 100 amps/hour. Maybe it only has 50 amps/hour left? That would mean it drains (with 0.45 amps) in about 4.6 days. Which is pretty much exactly what it does at the moment.
Obviously, the battery would still need to be replaced. But I want to fix any drains in the system before I throw away another 100 bucks on another new battery.
After all, a car like the 75, should well be able to stand still for a few weeks without getting a flat battery. Mine had no problems with my 19 days holiday in 2017.
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Old 5th June 2020, 09:58   #34
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Quote:
Originally Posted by Supervinnie40 View Post
This is the amps after connecting everything and waiting for 10 minutes. Battery has just been charged.
I'll check again in about 2 hours to see if it has changed.

In case it matters: the car is unlocked with a clamp on the bonnet switch. I closed the boot as last, and waited 10 minutes to make the photo.

It's a tad high, but already lower then in the past.


I think you are operating your meter incorrectly.
As per your photo, when the meter is on the 200mA range, the red probe needs to be plugged into the middle connector labelled 200mA MAX.
When the meter is on the 10A range, you use the TOP connector, as in the photo.
Using the top connector and 200mA range will give unpredictable results.

I'm surprised nobody has noticed your error.
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Old 5th June 2020, 11:14   #35
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Quote:
Originally Posted by MarkS View Post
I think you are operating your meter incorrectly.
As per your photo, when the meter is on the 200mA range, the red probe needs to be plugged into the middle connector labelled 200mA MAX.
When the meter is on the 10A range, you use the TOP connector, as in the photo.
Using the top connector and 200mA range will give unpredictable results.

I'm surprised nobody has noticed your error.
I didn't notice that to be honest . I'll redo this test tomorrow to see if it gives me different numbers. Thanks for the sharp eye.
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Old 5th June 2020, 11:26   #36
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Quote:
Originally Posted by Supervinnie40 View Post
I didn't notice that to be honest . I'll redo this test tomorrow to see if it gives me different numbers. Thanks for the sharp eye.
Vinnie,

I pointed that out to you in post 22! You replied that you didn't think it mattered.

The problem is that to move the probe to the 200mA socket involves breaking the circuit. When it's re-made the initial current will exceed 200mA and will almost certainly damage your meter.

Simon
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Old 5th June 2020, 13:15   #37
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Originally Posted by SD1too View Post
I see from your photograph that you cannot hot-switch from the 10 amp range to the 200mA range because you need to move the red probe to a different socket.
I thought you where refering to the dial? Like I can't turn the switch without moving the red probe to something else (like the minus lead from the battery or something). It kinda did confuse me, but I assumed you knew what you are talking about. And you do, I just misunderstood it
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Old 5th June 2020, 13:27   #38
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Always use time as reference to battery charging NOT distance travelled.

An alternator and a battery charger put around, on average, about 5 amps into your battery.

24 hours charging on a charger equates to about 24 hours driving your car with the alternator doing the charging.

The charger might cost you a pound or two. Driving your car for 24 hours might cost between £150.00 and £200.00.--


I'll leave you to guess which is the best option.---
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Old 5th June 2020, 15:51   #39
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Lol, the charger will be the prefered option haha.
But nonetheless, I am inclined in thinking that the car should be able to survive a few weeks without being used. Currently I get a few days max out of it.

The search will continue tomorrow. Right now I'm testing the level of discharge when the battery is not connected.
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Old 5th June 2020, 15:59   #40
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Just checked the voltage. It now says 12.25v. This after roughly 48 hours.

Just after being charged: 12.45
24 hours later: 12.29
Again after 24 hours: 12.25.
Considering that the battery might give a high reading just after being charged, I rather look at the last 24 hours. Which says it lost 0.04 volts over 24 hours.

I'm not sure what that really says, but if the car won't start with anything lower then 11 volts. I still have 31 days before the battery is at 11 volts.
Off course, this is without any load on it. When I reconnect the leads, it will give a very different picture.

Am I right in thinking that it is not very plausible that my battery is the problem? Have I rulled this out enough to say that I should keep looking at the amp-drain from the car's electronics?
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