Help please to improve electrics on a 90TD

Hi all

I have a 1990 90td which I use for quite a lot of short off-road journeys. Now that the winter is here with the dark nights etc I wish to add some additional lighting on to the roof bar and A bar. My problem is that with a lot of short journeys the battery tends to run down anyway and with more electrics draining the sytem I think this will only get worse. Does anyone have any idea how I can upgrade the capacity of the charging system with out going to massive expense? I am not an auto-electrician but can handle simple DIY jobs. I was hoping that perhaps I could buy an upgraded alternator (I think my current one has output of 65amps - would fitting a bigger one help or blow the whole thing up??). I have heard of people fitting two batteries but would have no idea about how to go about this. A bolt-on improvement would really suit me best.

Any advice greatly appreciated.

Thanks

How about getting an Optimate battery charger, taking wires from the + and - teminals on the battery to an electrcal socket mounted in a convenient place in the cab, put a plug on the Optimate wires and "plug" the Landy in overnight.

Could work out cheaper than a new battery. And would keep the battery in good condition.

if you can't do that for what ever reason then you should be able to get a more powerfull alternator that will just bolt straight in the same place as the other one

Thinking on it a bit more now the tears have cleared up.

Just putting a second battery in wouldn't help much, would it?
you would still have the same power input regardless of how many batteries you have.

It's a matter of keeping the power input the same as or greater than the power used, isn't it?

I'm sure someone with more electrical knowlege will be around to put us right.

yer not wrong i bigger battery would just last longer before it went flat. you need a higher out put alt, or you could try one of them solar chargers that you plug into the fag lighter .i got no idea if it will be any good in winter or not.
or just eat lots of carrots till the lighter evenings are back

What about put on a chargingcontroller instead of the one on the alternator .? Very often this one are not giving the correct volt that one need in cold weather.The most efficient are to have a chargingcontrollbox fastened on the battery.That could feel the correct temperatur and therefor give moore power in cold clima.You know that the temp on the alternator can be much higer than on the battery under the seat. Here in Norway where i lives there is a Company by name Ladac , they are manufacturing several types to plug on ,and then cut out the integrated one. If your alternator gives 14,3 volt ore less instead of 14,4 volt that could be enough lack to never get " guts " on your battery ,but also caused by many short trips with high output .
Thats all folks from the North.

its not the volts that the problem its the lack of amps. down in old blighty it don't get as cold as up north . if the alt wasn't shoving out enought volts the warning light would be coming on. which i don't think is the case here.

Hi. There is a connection between volt out from the alt.and how good the condition of your battery is. It could never be enough " guts" if it doesn`t charging with correct volt,14,4. First, the regulator itegrated on the alt.can give out slightly under 14,4 , let`s say 14,1, and the charginglight wouldn`t warn you about that. That level is on some alternators (cars) in the " normal" area.On top of that, very often there is a " lack" of volt on the way from the alt.(regulator) to the battery, and a buildt-inn regulator is not good enough to compensate for that, mainly because of its place on the alt. The volt must be 14,4 volt on the battery poles when charging and therefor an optimal external chargingcontroller which senses the volt on the battery, by temp. and amps are absolute the best . I will recommend in the first place that you check up the charging regulator, and note the volt on your battery when the engine runs. If it`s under 14,4 your battery will " never" be top charged unless you compensate it by using an external ordinar charger. The battery can also be damaged by time and not take charging.

Really big boobs , i must say.Guess there`s enough amp`s there pal.
Have a nice christmas all of you and be good to all animal.
The Norseman

Yes!!!!,.....we have no bananas!!!

You're right I don't have a pronblem with the warning light coming on, it's just that after a few weeks the battery begins to sound a bit tired so I take it out and put it on the charger. I assume that by adding more lighting this will only increase in frequency. As to bolting on a higher rated alternator, do you have any idea where I could buy one??

Thanks for all you help so far

due to the way the warning light works if it go out then the alt voltage has to be higher than the batt voltage therefore it must be charging. i have no idea where you get this 14.4volts from.. each cell in the batt has a voltage of 2.2 v so that six of them add up to 13.2v.
an alternator is capable of producing a lot more volts than is needed so even if the cold affected it then as long as it is it good condition it will be capable of producing the required voltage.
when your engine is running the electrical system is actually running off the alt output and not the battery, unless you are using more power than the alt is producing.
the reason short runs are bad for the batt is because starting uses a lot of batt power and it takes time to re charge the battery. so if you are using heater, radio,lights,extra lights,rear de-mister and any thing you may have then there is less available for charging the batt. which is where a higher output alt comes into its own.

as to where you could get one ,you could try a breakers yard. if you go armed with the alt type and amperage required they might have one on the shelf. or you could try a specalist landy place paddock or cradocks or bearmach spring to mind

and if you want 'guts' on yer battery why not find some roadkill and just pop the bonnet and lay roadkill on top of battery?

Hi there,

The standard alternator on you TD in good working order will put out more than enough current even with extra lights. The TD uses minimal power, all the engine needs is a about 1 amp to run the fuel stop solenoid, and assuming original lights thats not going to come close to its full capacity.

A standard car battery needs more than the 13.2 volts to charge it due to internal losses, but over 14volts is enough.

Two things I would do before going any further. Check the output voltage of the alternator with a digial multimeter. Take a reading off the battery with the engine running. On tickover you should be getting close to 14v but with the engine on a fast idle you should definatly be getting over 14v. If thats OK I suggest you disconnect the battery and leave it on a trickle charge overnight. Once it has fully charged connect it back up and put your lights on (without the engine running) and check the battery voltage. It should be reading around 13+ volts. If its not then your battery is knackered and isnt holding a charge properly. If its an old style one with removable cell covers you can top it up with distilled water and then go through the charge / check procedure again. If its still no good then I suggest buying a decent battery.

I say fully charge the battery on trickle charge because if your using a fast charger your battery wont be getting a full charge. Similar principal to an alternator - they are no good for charging a discharged battery. Old dynamos were ideal for that because the voltage dropped with current draw. Alternators and fast chargers maintain a constant voltage.

If your alternator is not putting out the correct voltage then the best thing to do is find a local reconditioning specialist and let them rebuild it - it will be cheaper than a new or even remanufactued one from a shop.

The 'intelligent' regulators are a good idea, but their main purpose is to load the voltage sensing circuit to make the alternator 'think' that the battery is always flat in order to maximise the current out of them. Ideal if you are fitting twin batteries.

Something else to check if you have a digital multimeter. With the ignition off place the meter in series with the battery on its current setting. If you dont have an alarm / clock in the car you should not be getting any current draw. With a clock or alarm you could be getting upto 200mA. Anything over this would indicate that there is a circuit that is draining the battery. If you have remove the fuses one at a time to find out which circuit it is. If you are still getting a drain with all the fuses removed I would suspect a faulty regulator.

Hope this helps,

Craig

hello
from what i read the op doesn't have a problem under normal conditions, its only when he is driving short distances. and as it takes about two weeks for the battery to show any ill effects. goung throught the whole "mm! i must have a leccy drain somewhere routine" seems abit much. as i understand it the op is looking for a way to avoid having to charge the battery every couple of weeks.
if you are driving slowly with lots of electrical stuff on (not just the engine) then the alt could have a problem keeping up, you only have to start your engine then switch on headlights ,de-mister and such and you will hear the engine slow down a bit as the alternator is putting up more resistance to turning, even on a new car.
the alternator is designed and geared to operate most efficantly at normal driving speeds not slow speeds. which means you either drive in low ratio(to keep the revs up) or fit a more powerful alternator
hugh

A 65 amp alternator will take pretty much anything a 90 can throw at it.

Before you start thinking of up grading, whip it off and get it load tested. May only be a matter of a couple of new brushes. pence compared to pounds!

Thanks to everyone for your help. Hope you all had a nice Christmas.

In the end I took the alternator off and got it tested. No output at all!!

So I bought a new standard one, and now it all appears to be fine. Thanks again for you help.

Sounds like it's all sorted now but a couple of xtra comments (and general electricals maths)...

Local parts suppliers will do you a battery load test for free. Two batteries wont make a difference nor will any charging gizmos to this kinda problem.

To figure out if your alternator is up to the max load, here's how, using the equation:

Power in Watts (W) = Amps (A) x Volts (V)

Multiply your count of headlights+spotlights by 55(W) - assuming you have road legal bulbs in everything. Then add 72(W) which is the total for front and rear sides (5W each) plus the brake lights (42W together - kinda unfair cos your brakes shouldnt be on ALL the time eh...) and an extra 10w to correct for std mainbeams which'll actually be 60w each.

For example, 2 headlights + 4 spotlights = 330 + 72 = 402 watts
Divide by 12 (V) = 33.5 amps (A)

Even with the heater on and a std alternator of 65A should be able to keep up. The output rating will be on the plate on the alt btw. If your load is close to the alt rating, it's not a problem with occasional use of the spots cos your battery will donate the extra and then be topped back up by the alternator once you turn em off... but prolonged use will drain the battery.

Assuming you've not gone mad with lighting then the std alt rating will almost certainly be OK ... but the maths will tell you for sure if you need to buy a new one.

One more thought - remove the bolts that hold the earth strap to the engine (or gearbox) and clean the contact surfaces. When these corrode it will affect the ability for the alternator to deliver high current back to the vehicle. You are also likely to see starting problems will this little one too.

Hope that lot helps someone...

Gadzooks TDI. Is this the equasion Slob was on about.

Can't we go back to the days when you parked up somewhere dark leaving the engine running you switched on all your electrics, lights, heater, wipers (if they work), Demisters, curling tongs (if your in a Freelander). Then revved up your engine, if the lights brightened up noticably then your alternator was working.

If someone tapped on your window you've picked the wrong layby and its someone from the news groups down the bottom of the page out dogging.

i guess he got a "my first electronic kit" for xmas

yeah sorry. i was having a very nerdy electrical engineer moment