Many thanks once again. Having read what everyone has to say, including your goodself, I have decided to leave well alone and accept that I may never know if the charger switches off or not. Like you say, I don't think it will do any harm to leave it on for a while after the "Green" light shows and I have decided to use a timed plug socket just to be on the safe side and adjust the "on" hours if necessary. Many thanks all of you for your helpful input.

 

Happy E-biking !

I have decided to leave well alone and accept that I may never know if the charger switches off or not.

 

There is a simple way to find out. Purchase an energy consumption monitor for a tenner. When the charger is actively charging the batteries, the monitor will show around 50-70w. When the charge indicator turns green, the consumption will reduce to just a couple of watts...the power used by the chargers electronic components.

These consumption monitors have many uses around the home, so not a waste of money.

 

The resident "experts" will of course disagree

 

http://www.maplin.co.uk/p/13a-plug-in-energy-saving-monitor-n67fu

There is a simple way to find out. Purchase an energy consumption monitor for a tenner. When the charger is actively charging the batteries, the monitor will show around 50-70w. When the charge indicator turns green, the consumption will reduce to just a couple of watts...the power used by the chargers electronic components.

These consumption monitors have many uses around the home, so not a waste of money.

 

The resident "experts" will of course disagree

 

http://www.maplin.co.uk/p/13a-plug-in-energy-saving-monitor-n67fu

This will not tell you the whole story. I have come across SLA chargers that hold the cells at a voltage higher than is recommended and although at this point very little current flows, the electrolyte continues to boil away.

 

The saving grace with lead acid batteries though, is that they are about as 'safe' as a battery can be. Although there is a small risk of an explosion due to over-pressurisation, the fire risk is pretty much zero. In reality though, an explosion is unlikely because of the way that the hydrogen produced is vented. This is what the hissing sound is when an SLA is charged to an excessive voltage.

Edited August 12, 201411 yr by danielrlee

It's an electric bike, not a WW2 diesel-electric submarine. Nice example of "gish-galloping" though.

 

Bernie2 wanted a safe way of finding out if his charger shut down when the battery was fully charged. The electrolite in the lead-acid batteries used in electric bikes is in gel form. When gel batteries reach the end-of-life due to high internal resistance, some corrosive liquid may escape through the venting ports but no appreciable gassing will occur.

It's an electric bike, not a WW2 diesel-electric submarine. Nice example of "gish-galloping" though.

 

Bernie2 wanted a safe way of finding out if his charger shut down when the battery was fully charged. The electrolite in the lead-acid batteries used in electric bikes is in gel form. When gel batteries reach the end-of-life due to high internal resistance, some corrosive liquid may escape through the venting ports but no appreciable gassing will occur.

What Bernie has asked isn't all he needs to know and I can only repeat what I've already said. A watt meter that sits between the mains socket and charger will not tell him the voltage that the charger is holding the battery at. This is an important piece of information and needs to be known if we are to tell him that it is safe to leave the charger connected. Anything else would be guessing.

 

EDIT: In my opinion, the best SLA chargers never 'turn off', but instead monitor the battery voltage and when it drops below the 'float voltage', momentarily applies power to make sure the battery is always fully charged. It will then return to the monitoring stage and continue this cycle indefinitely. This solves the self-discharge issue that SLA's suffer, especially when there are long periods between usage.

Edited August 12, 201411 yr by danielrlee