battery

Posted by davy on 2011-04-24 22:05:00 

Hello,

I bought a new battery for my 1390 5 months ago,and had to put another in her yesterday, the battery was a 96ah, but i was told it was to light for her, is it to light?
I got it tested and it was ************, i was surprised because it only new, i have a new alternater also, so i know that it wasnt the cause off the battery being dead,, the name off the battery is a dynamic, any advice would be appreciated..


john
Posted by: jimc1390 on 2011-04-24 22:16:00 
should get a refund or replacement for that
Posted by: Guest on 2011-04-24 22:37:00 
Quite right! The battery could well be 'old stock' and several years old and 'shifted' as a new one. You can always find out the manufacture date of a battery by contacting the manufacturer or original supplier and giving them the date code that is stamped or 'melted' into the casing somewhere. I had a new battery for a car some years ago and it would not start the car, I took it to a specialist firm that sells batteries and exhausts and they told me that according to the date code it was 10 years old, I soon marched it back to where I bought it and demanded a new one. 96Ah should be plenty strong enough.
Posted by: broadsword on 2011-04-24 23:21:00 
Hi John,

as Powerrabbit has said 96ah is plenty strong enough for a 1390 - most batteries come with a 1,2 or 3 year warranty depending on price or perhaps a 5 year warranty for an expensive battery - if you have the receipt then take it back and you should be entitled to a new one.

However if it is a non-sealed type - ie you can top it up, is it low on water on one of the cells?? - if it is then your alternator may be overcharging and it has boiled the water away on one or more of the cells - again I would exchange the battery but may be worth checking.

Cheers

Andy
Posted by: davy on 2011-04-24 23:32:00 
Thanks,
I got a replacement, yesterday, it is the same battery as before, so am hoping it will last a bit longer this time..
I was going to put on a volt gauge, what should the volt gauge be reading if the battery is charging properly?

John
Posted by: calvin on 2011-04-24 23:51:00 
hi john had a battery out of a dumper volt meter read 6 volts charged it up then it read 12.4 so put it in a ford 4000 after putting the cables on i tested the battery it readed 6 volts it was near new whent back with it got a replacement for half price and it was 3 mounths old it was
Posted by: davy on 2011-04-25 00:21:00 
Yes, but when a 12v battery is charging properly, what should the gauge read? shouldnt it read higher than 12volts?
Posted by: Guest on 2011-04-25 08:32:00 
Battery charging with engine running should on a dynamo be reading 13.4V and on an alternator be 17.5V. A battery needs more power input on the charge side of the circuit than the batteries capacity to maintain a charge. Looking after a battery involvs keeping the fluid level to just over the top of the plates and making sure that it can vent properly, usually from little appetures in the cell filler caps and if you need to top up any of the cells it should be with distilled water, water that has had no contact with any metallic materials, idealy rain water or melted ice from your fridge or deep freezer is ideal. Keep them clean as well. If leaving for a long time you should remove the battery from the tractor and put on a battery charger to keep it up at least every three months and never place it on a cold concrete floor, keep it up off the ground on a bench or on a sheet/plank of wood. Both batteries in 2 of my tractors are both over 12 years old now so it goes to show that they will give good service if looked after. At a price of around £70 now for the cheapest tractor type batteries it pays hands down.
Posted by: davy on 2011-04-25 10:45:00 
Thanks powerrabbit,
That information was very helpfull,

Cheers

John
Posted by: alanc on 2011-04-29 22:30:00 
For information on Lucas dynamo and alternator diagnostics and charging rates search web for 'lucas fault diagnosis service manual'

My lucas test sheets for dynamo charging rate show 14.5-16.5v, depending on regulator type. Alternator charging rate for 15ACR-20ACR (integral regulator) is 13.6-14.4v.

These are typical figures for 0-25degC and vary slightly for other temperatures
Posted by: John_Allen on 2011-04-30 09:33:00 
I'd go with Alan's figures - a lead acid cell in good condition should have 2.2v across the terminals - so a "12v" battery, with six cells, should have 13.2 v at its terminals, so I would expect a charging voltage of 14v under normal conditions - I seem to remember my old dynamo-equipped Mini used to charge at 14.7v (in the days when it looked good to have loads of gauges in cars!)
Posted by: trackhappy on 2011-05-03 12:54:00 
A modern alternator running with a fully charged battery will regulate at 14.6-14.7 volts. Too much more and it is overcharging the battery. A nominal 12 volt battery not charging with a small load will quickly level out at a little over 12 volts, so if the engine is running and the voltage stays at 12-13 volts then the alternator is not charging. As Alanc states, temp makes a difference, but it is very small. With a generator (dynamo) as far as I am concerned all bets are off. They regulate current more than voltage and can be very inaccurate unless carefully tweaked. That said, if the voltage reading is going much above 14.7 then over time it will kill the battery generally though their lower output capacity tends to be kinder anyway. I have found through personal experience that letting batteries go flat is more of a problem in these types of vehicles as they are not used regularly or for long enough.