puter
Senior Member
- Joined
- Sep 24, 2005
- Messages
- 116
- Reaction score
- 0
- Location
- Congleton. Cheshire
- Your Mercedes
- R129 SL500, SLC 200.
This is the scenario which has worked for me. No way do I claim it is the best way, only one based on my electronic and electrical background.
My first battery failed after about 4 years, a situation I didn’t like, causing me to investigate.
Handbook said battery is maintenance free. Examination of the battery after removing the cover revealed it to be a normal lead acid type. Needless to say there was very little liquid in it which had contributed to the failure. Dialogue with Merc service manager confirmed they followed a no maintenance procedure, but came back in 2 hours rather sheepishly.
Fortunately we enjoy a first class battery and tyre shop nearby run by a bright lad. His recommendation was to use the largest Fulman battery that would fit. His advice served me well. Because of the tactics I have used and the battery quality, 11 years later the battery is still serviceable.
Parts required:
Time switch, Hydrometer, Constant Voltage charger with a maximum capacity of 4 amps. These are called various things, caravan chargers, battery maintenance chargers etc
The charger I use was manufactured by Gunson. It has a double wound mains transformer a full wave rectifier and designed for continuous use. The time switch is a plug in mechanical mains driven unit, without any back up facility. The hydrometer is a standard off the shelf unit, but check the calibration on a fully charged battery before placing into service.
In use.
Much has been said about connecting chargers without disconnecting the battery. I have never had problems following these guidelines. Switch off ignition and remove key, connect charger to well lubricated battery terminals, set charger to AUTO 100% charge, connect to time switch and initially set timer to switch once every 24 hours for a period of 3 hours. For the first few days check each day the level of charge using the hydrometer, if fully charged reduce time to 2 hours. Fine tune the time on until the discharge of the alarm system and natural discharge of the battery is matched to the charge time. To correctly achieve this, the time on must be reduced until a less than full charge is noted, next increase on time a few minutes at a time to correct this. Once balance has been achieved the system can be left to do its job. An ordinary trickle charger could be used instead of a fancy auto; I just like the added safety in case my time clock jams on. Remember to check the battery liquid level regularly, never place the charger in the boot and ensure ventilation.
As an extra safeguard I have a warning notice attached to a large bulldog clip, which is clipped to my steering wheel in order to prevent me jumping in, reversing out with charger and leads in tow.
Comments.
It is my experience batteries do not like to be continuously charged even on fully auto chargers, this little exercise period provided by time on and off is, in my opinion is just as good for batteries as humans! There it is a simple system that doesn’t break the bank and has stood the test of time for me.
My first battery failed after about 4 years, a situation I didn’t like, causing me to investigate.
Handbook said battery is maintenance free. Examination of the battery after removing the cover revealed it to be a normal lead acid type. Needless to say there was very little liquid in it which had contributed to the failure. Dialogue with Merc service manager confirmed they followed a no maintenance procedure, but came back in 2 hours rather sheepishly.
Fortunately we enjoy a first class battery and tyre shop nearby run by a bright lad. His recommendation was to use the largest Fulman battery that would fit. His advice served me well. Because of the tactics I have used and the battery quality, 11 years later the battery is still serviceable.
Parts required:
Time switch, Hydrometer, Constant Voltage charger with a maximum capacity of 4 amps. These are called various things, caravan chargers, battery maintenance chargers etc
The charger I use was manufactured by Gunson. It has a double wound mains transformer a full wave rectifier and designed for continuous use. The time switch is a plug in mechanical mains driven unit, without any back up facility. The hydrometer is a standard off the shelf unit, but check the calibration on a fully charged battery before placing into service.
In use.
Much has been said about connecting chargers without disconnecting the battery. I have never had problems following these guidelines. Switch off ignition and remove key, connect charger to well lubricated battery terminals, set charger to AUTO 100% charge, connect to time switch and initially set timer to switch once every 24 hours for a period of 3 hours. For the first few days check each day the level of charge using the hydrometer, if fully charged reduce time to 2 hours. Fine tune the time on until the discharge of the alarm system and natural discharge of the battery is matched to the charge time. To correctly achieve this, the time on must be reduced until a less than full charge is noted, next increase on time a few minutes at a time to correct this. Once balance has been achieved the system can be left to do its job. An ordinary trickle charger could be used instead of a fancy auto; I just like the added safety in case my time clock jams on. Remember to check the battery liquid level regularly, never place the charger in the boot and ensure ventilation.
As an extra safeguard I have a warning notice attached to a large bulldog clip, which is clipped to my steering wheel in order to prevent me jumping in, reversing out with charger and leads in tow.
Comments.
It is my experience batteries do not like to be continuously charged even on fully auto chargers, this little exercise period provided by time on and off is, in my opinion is just as good for batteries as humans! There it is a simple system that doesn’t break the bank and has stood the test of time for me.
