......in his toolkit.

Maplin's have a digital multimeter on sale -- and it looks real cool.
£8 to you sir.
Ask for model UT 30B.

Re. batteries (again), I've managed to salvage the original Halford's battery that came with the car when I bought it. It said "72a/h" on the case, but proved to only have 20a/h capability. Fortunately, it's a sealed wet battery, so I was able to both de-suphate AND cure any acid stratification. Now it has 60a/h capacity, and I shall use it as my helper battery. It's a calcium laced one, and after a whole day has still most of its surface charge left. So it must be true what they say about calcium batteries -- they don't self-discharge too quickly. I believe Halford's batteries are german Sonderheim, but I've prob. mis-spelt that.

Leedsman.

 

Hi All

Talking about Maplins the £20 solar charger mentioned by Hellashaggis is £9.99 at the moment and trust me it really works. My battery (Exide EB741) is 3yrs old fingers crossed. Mind the other day the starter was a bit sluggish checked the battery condition indicator to find it black not green. turned out to be a wire off in the plug of the solar charger. Quick solder job and a 60 mile run and alls well again. Just shows the charger works as most weeks the car isn't used for several days in a row.

Regards John.

 

My Optima redtop battery and alternator were replaced 4 years ago by Chrysler dealer. The new battery was the Mopar 48AH, always getting flat battery from interior lights etc. Got fed up with this and replaced battery with Excide Excel (741B I think) of 70 something AH and no flat battery since.

However always thought the battery voltage was a bit low 13.2 - 13.4 engine running. Engine off and cold voltage could be as low as 12.4 v

Thought I would give Leedsmans idea a go.

I used a 3 position switch so can have 33k resistor in circuit, open circuit and closed circuit (normal), there is a convenient hole to mount the switch on the bottom edge of the battery tray.

Findings so far.

1. Engine running 14.29v dropping to 14.24 after 5 miles. with resistor in circuit.
2. Open circuit 14.07v, I guess this could be the innaccuracy of my cheap meter?
3. Standard (without resistor in circuit) 13.6v dropping to 13.4 v

I had to use two 1/4 watt resistors in parallel, shouldn't make a difference?

I just did the "keydance" after 5 miles driving with the mod and had five "P0514" codes which I understand is "Battery Temp Sensor Circuit Signal Voltage too High/Low".

I did have about thirty or so "P0340" (crankshaft sensor, I have a new sensor but haven't got around to changing it yet) which have dissappeared. Hmmm...maybe I don't have a faulty crankshaft sensor?

I think I'm going to switch back to the standard untill I can get one of those plug-in (cigarette lighter socket) voltmeters to monitor it. I think I might be a bit close to the gassing voltage. From what I've read that could be 14v at 40 degC, could easily be 40 degC in the engine bay?

I suppose Chrysler make these vehicles to go in countries from +40 DegC to -20 or so, thats a huge temperature swing and the temperature sensor (attempts!) to adjust for it. Are we trying to "finetune" it for the UK? And to use Standard lead acid rather than redtop spiral wound batteries?

Just another thought, did anyone try some of the thermal transfer paste between the battery and sensor (the stuff used on processors and their heat sinks) could make a difference?

Like others on here I think Leedsman has done a great job with this, I'll certainly contribute what I find out.

Thanks again Leedsman

 

rodger

Lifestyle plays the biggest part in the issue of the UK CRD's, its certainly the case with Leedsman and I that this 'lack of use per week' is our major problem. I have a plug in module for my smartphone [this is an alternative one] and an Autel for real time datastream readings. If you have an android I can confirm they work ok, a bluetooth or wireless ODB2 adaptor would be required.

Good work Rodger, I like the idea of the 3 way, a 4 way with both a half and a full watt would be a handy test[er]

- Spirals, never rated them on these vehicles
- for myself anything other than old style 'merc spec' lead acid at 800/80 is any use
- gassing at 40°C ? I'll have to think about that, I agree with you many engine bays will be that in our summers
- the precise voltage / Ohms resistance info is in the Workshop manuals
- can't see that the 'accuracy' that thermal grease will give will help
- "finetune" it for the UK?" - no, for myself its "finetune" it for the lifestyle and UK ?

Essentially these GV diesels undercharge for the amount of BUS drain when not in use. They certainly undercharge for our cold weather, and even as early as November people with an infrequent use lifestyle can and do have starting problems. So my needs are .. .. how do we get enough old style 14+v into and old style lead acid battery in a short infrequent run in those 5°C- weeks in our winter ? I used a tiny and has no starting issues, I now have still boxed which I may put to the test if I need to but as stated the little one sits passive and innocuous on the dash and as the say did it for me last winter.

- can you link the 3 way switch you used ? for me please ?

- Leedsman did you test the 1 watt instead of the half and did the outcomes improve ?

 

Re. 33K0 resistor wattage, a quarter watt will be fine, sensors are powered by a tiny current from the micro's TTL logic voltage of 5volt.You could fit a 50K0 potentiometer if you wished instead of the resistor and adjust the charge voltage to exactly what you want. Maybe a little more oomph in winter? And yes, digital meters can be inaccurate. Check with a NEW 1.5volt zinc-carbon cell. There is an internal pot. in digital voltmeters to adjust the voltage displayed accurately. I do believe there is a bright-spark maker now supplying a small DVM only to monitor your battery voltage all the time infront of you on the fascia.

Re. battery gassing, 14.4volt as a charging voltage (the constant-voltage principle) was originally chosen as the highest charge voltage that could be used without noticeable gassing. Most authorities seem to agree with this. During bulk charging where the battery gets 80% of its total stored energy, there is no gassing at all. Modern sealed batteries convert the separate gasses hydrogen and oxygen produced in overcharge back to water in a catalytic manner, especially the jelly batteries.

It's very important indeed with a starter battery in a car to keep it as near 100% charge as possible. This is 12.73volt when the surface charge has dissipated after 24 hours or so. 12.1 volt is the 50% of charge figure. Don't let it get below 12.6volt if at all possible. Even running it at 80% charge most of the time will badly limit its service life. In the old days with wet batteries and 14.4volt fixed charging, a service life of anything up to 10 years was common and expected. But then there were no alarms and several micro processors demanding power ALL THE TIME. So much so, the average service life of a car battery is now around 2 years. And of course suppliers and garage mechanics will be very happy to sell you one. Ker-ching.

If anyone wants it, I have ways of reactivating these 2y/o batteries, but no guarantees. It depends how far crystal sulphation and acid stratification has gone. The "old" battery on my GV has been rescued and is now the "helper" battery. This will be needed come winter.

If anyone has electronic problems with any car, not just GVs, feel free to inquire here.
There is NO CHARGE lol. Oh very droll.

Leedsman.

Addition: The "gassing" from lead-acid is not the same as evaporation. In very hot climates, it is possible but unlikely that the water in the dilute acid will evaporate due to strong chemical bonds between H2SO4 and H2O. The gassing talked about is the breaking down of water into hydrogen (H2) and oxygen (O2) by the passage of an electric current. This is the classic electrolysis of water as in all school's physics lessons, made easy by the highly conductive sulphuric acid. Plain water is not very conductive. The presence of oxygen and hydrogen over and around the gassing battery was the reason we were told not to light a cigarette with one's face over the battery when gassing!

 

I have a 700CCA gel filled battery about 3 years old.

I drive about 30miles everyday to and from work plus whatever other journeys, so about 1000miles/month.

There isn't anything wrong with the charging of the battery or the condition of the battery but here's the situation.

Drive to work, leave for 9 hours - battery flat.
Come home from work, leave overnight - battery flat.
I now have to carry a spanner and disconnect the earth at work and over night!
But if I disconnect the battery on a Friday night and connect on a Monday morning it'll be fine.
This makes me think that there's nothing wrong with the battery, but some internal circuitry thats taking excessive power when the key is out.
Its not the alarm, as I've left it unlocked and it'll go flat.

Just thought I'd have a therapeutic whinge on some sympathetic ears!

 

- here's a bit of light reading to help your understanding pob my friend
- at 3 years it could still be getting borderline
- agreed weird that two days 'off pole' and it will start
- big red key is a short term solution to pulling the cables

The maximum you should see is 50 milliamps or .050 on a meter.

IGNITION-OFF DRAW TEST

The term Ignition-Off Draw (IOD) identifies a normal condition where power is being drained from the battery with the ignition switch in the Off position. A normal vehicle electrical system will draw from fifteen to twenty five milliamperes (0.015 to 0.025 ampere) with the ignition switch in the Off position, and all non-ignition controlled circuits in proper working order. Up to twenty-five milliamperes are needed to enable the memory functions for the Powertrain Control Module (PCM), digital clock, electronically tuned radio, and other modules which may vary with the vehicle equipment. A vehicle that has not been operated for approximately twenty one days, may discharge the battery to an inadequate level. When a vehicle will not be used for twenty one days or more (stored), remove the IOD fuse from the Integrated Power Module (IPM). This will reduce battery discharging. Excessive IOD can be caused by:

• Electrical items left on.
• Faulty or improperly adjusted switches.
• Faulty or shorted electronic modules and components.
• An internally shorted generator.
• Intermittent shorts in the wiring

If the IOD is over twenty five milliamperes, the problem must be found and corrected before replacing a battery. In most cases, the battery can be charged and returned to service after the excessive IOD condition has been corrected. (1) Verify that all electrical accessories are off. Turn off all lamps, remove the ignition key, and close all doors. If the vehicle is equipped with an illumi-nated entry system or an electronically tuned radio, allow the electronic timer function of these systems to automatically shut off (time out). This may take up to twenty minutes. (2) Disconnect the battery negative cable. (3) Set an electronic digital multi-meter to its highest amperage scale. Connect the multi-meter between the disconnected battery negative cable terminal clamp and the battery negative terminal post. Make sure that the doors remain closed so that the illuminated entry system is not activated. The multi-meter amperage reading may remain high for up to three minutes, or may not give any reading at all while set in the highest amperage scale, depending upon the electrical equipment in the vehicle.

The multi-meter leads must be securely clamped to the battery negative cable terminal clamp and the battery negative terminal post. If continuity between the battery negative terminal post and the negative cable terminal clamp is lost during any part of the IOD test, the electronic timer function will be activated and all of the tests will have to be repeated. (4) After about three minutes, the high-amperage IOD reading on the multi-meter should become very low or nonexistent, depending upon the electrical equipment in the vehicle. If the amperage reading remains high, remove and replace each fuse or circuit breaker in the Integrated Power Module (IPM), one at a time until the amperage reading becomes very low, or nonexistent. Refer to the appropriate wiring information for complete Integrated Power Module fuse, circuit breaker, and circuit identification. This will isolate each circuit and identify the circuit that is the source of the high-amperage IOD.

If the amperage reading remains high after removing and replacing each fuse and circuit breaker, disconnect the wire harness from the generator. If the amperage reading now becomes very low or nonexistent, (Refer to 8 - ELECTRICAL/CHARGING - DIAGNOSIS AND TESTING) for the proper charging system diagnosis and testing procedures. After the high-amperage IOD has been corrected, switch the multimeter to pro-gressively lower amperage scales and, if necessary, repeat the fuse and circuit breaker remove and re-place process to identify and correct all sources of excessive IOD. It is now safe to select the lowest milliampere scale of the multi-meter to check the low- amperage IOD. CAUTION: Do not open any doors, or turn on any electrical accessories with the lowest milliampere scale selected, or the multi-meter may be damaged. (5) Allow twenty minutes for the IOD to stabilize and observe the multi-meter reading. The low-amperage IOD should not exceed twenty-five milliamperes (0.025 ampere). If the current draw exceeds twenty- five milliamperes, isolate each circuit using the fuse and circuit breaker remove-and-replace process in Step 4. The multi-meter reading will drop to within the acceptable limit when the source of the excessive current draw is disconnected. Repair this circuit as required; whether a wiring short, incorrect switch adjustment, or a component failure is at fault.

 

Pob, you can test the actual ampere-hour capacity of your 3-year old battery yourself easily, as I did.
Remove battery and charge in the normal way.
Strap a 12watt test-lamp across battery and note time and battery voltage.
Leave it running and go about your other business, but check every hour or so the battery voltage. A digital meter is best.
When it reaches exactly 12volt, it is considered discharged. (This is normal industry accepted figure).
Work out the time it's taken to get to 12volt exactly, and at a discharge of 1-amp from the 12watt lamp, this time figure shows your real, actual, ampere-hour capacity of that partic. battery. You may get a surprize when you look on the case of the battery, and see what it is intended to be. I did this with my own battery just after I bought the GV, and it showed just 20 ampere-hour! The case showed 72 ampere-hour.... After my rejuvenation process, and using the identical test procedure, it read 60 ampere-hour. The rejuvenation process took several weeks. This previously bad battery is now my second battery.
Explanation:--
Failure for any reason to keep a starter battery close to 100% charge will cause the normal amorphous sulphation from the usual charge-discharge cycle to become gradually hard crystaline sulphation which reduces the ampere-hour capacity of the battery. The hard crystals are a near-insulator meaning that many spots/areas of the plates become useless, and therefore the battery acts as if the plates have shrunk. In other words, the ampere-hour capacity diminishes.
If you wish, I'll describe my rejuvenation process, which anyone can do, and costs nothing.

The test procedures outlined by Quinteq should be done first to make sure the parasitic/invisible/24/7 load on the battery is within acceptable limits. An unacceptable parasitic load is the reason many batteries are failing prematurely. A lead-acid starter battery should last many years (an average of 7 years) IF IT IS TREATED ELECTRICALLY AS IT SHOULD BE.
Most so-called battery problems aren't anything to do with the battery at all.

Leedsman.

 

True, the claimed Ah on a new SLA battery if between 20°C & 25°C would be true, outside those temps °C it could be significantly higher or lower.

SLA's hate heat above 30°C, and at below 5°C they may never reach charge capacity hence my constant preaching a bigger 800Ah for UK use requirement.

SLA's normally self-discharge @ around 3% per month, the O/P's seems to discharge @ 3% per hour and yet hold charge when 'off pole' [@ the imagined annual guesstimate of 3% per month] suggesting parasitic drain.
Even inside the optimum temp characterises above a 3 year old SLA will only have 90% of its Ah - a 4 year old SLA will only have 65% of its Ah - a 5 year old SLA will only have 40% of its Ah. My point being in an imperfect real world UK use we will never get anywhere near those performance characteristics even with diligent float charging. Bottom line is at 65% any battery is useless for CCA and needs replacing as a starter battery regardless of how old it is.
I agree with every word

If 'pob' has not made any changes to wiring, particularly the radio circuit in the last several months, it will be a one by one pull of each fuse [doors closed and all switched off including the bonnet sensor taped down] to test. Ditto a one by one inspection of the loom. Perhaps Richard can shed some bright light on 'fast tracking parasitic leeching for Dummies' of whih I consider myself one.

For myself I'll go for the current battery being on the edge of CCA capability. One month ago we were 10°C higher, the car the oil[s] and importantly the battery. Wrap a 12v heater jacket on an axillary battery to that starter battery [in car] and I'll give 10-1 it will perform .. .. but continue its inevitable decline in CCA capacity.

 

I've just remembered -- there is one area where there can be an excessive ignition-off current draw -- that is the alternator. And because it's hard-wired to the battery with very thick cable, won't show in normal testing, -- no fuse.

Most alternators have six stud-rectifiers wired to the "earthy" ends of the six windings, the studs being screwed or force-fitted into a heat-sink inside. The way they are wired means the other ends of the six windings which are wired together for the output terminal, can only go +ve., thus charging the battery with slightly lumpy DC.

ONE of these stud rectifiers can develop a "back-leak" imposing a hidden discharge current on the battery, all the time.

How to test? Because the big high-current output terminal of the alternator has to be directly connected to the battery, you must carefully disconnect it without allowing the tool, spanner/wrench etc. being allowed to touch anything like grounded metal. Be careful on this one.

Then put your ampmeter/milliampmeter between alternator terminal and the wire you've just taken off it, negative to alt. terminal. Anything more than a few microamps and you've a faulty diode in the alternator. Of course, here you are testing at the working voltage, not by say, the 1.5volt battery in an ohmmeter. These faulty diodes are a known problem with alternators.

Unf. they talk about £380 for an alternator, but if you are a true handyman, you can find the bad diode yourself and replace it, using a diode from an old alternator, which diode of course you test first... Most alternators will use much the same current rating (40 to 50 amps) for the diodes, so it's more important that the diode will physically fit.

It's careful work, as you'll have to snip all the diode connector wires and measure each diode terminal to find the dodgy one(s) -- and naturally it will be the last due to sod's law, (+ve to each diode terminal should read no current). Then solder the all the wires back again. It will be necessary of course to use 12volt as a test source plus a milliampmeter (or if you don't have a suitable meter, a very low-wattage lamp might do, the smallest you can find, some light brightly at only 50m/A).
Addition -- "Diode" and "rectifier" mean the same thing. The word rectifier usually means a very big diode indeed such as was used to make 660volts dc. out of the then 240volt ac. in a mercury arc rectifier with three anodes and a big pool of mercury in the bottom of the glass vessel to power overhead tram wires.

Leedsman.