Intro: Trickle Chargers

Trickle Chargers are used both to charge batteries and to extend their life.  They should be relatively cheap to purchase and for the most part draw power from a static mains source.  Solar panels can also be used as a power source, perhaps while mobile.  They can also be known as battery tenders (there is a very popular firm of the same name – just to add confusion), battery chargers or battery maintainers (older batteries required maintenance; this is also, confusingly something else).

A Trickle Charger

A Trickle Charger(110537)


Most batteries for vehicles, such as: cars, motorbikes, boats, mobility devices, ATVs, Jetskis and snowmobiles are 12 Volt batteries and most trickle chargers are set for 12 V.  Those that are not are normally variable, with 6 Volts being a popular alternative.

Trickle charger characteristics

Trickle charger characteristics(110539)

The Power output will have a direct relation to how quick the battery will be charged. Power is measured in Amps (A) and a budget typical battery tender starts at 0.75A, 1.5A would be an effective mid range device.

What trickle charger is appropriate for which battery?

There are 2 major types of batteries – primary and secondary.  Primary types are designed to be disposed of once flat and are therefore not to be used with a charger of any description. 

Secondary battery types are:


Valve Regulated Lead-acid battery known as VRLA commonly used in cars.

The good news is that when choosing a charging device you must only check that is appropriate for your type of battery.  The most common type of batteries you will find will work with most trickle chargers.  It is there fore better to talk about exceptions; Gel Cell batteries require a different charging profile but are more expensive and can offer better performance.  Chargers can come with different programmes to allow them to charge Gel Cell batteries.

What is important when choosing a trickle charger for a motorcycle?

When choosing a trickle charger for a motorbike you should consider what is it that you need it for?  The most common reason people purchase a trickle charger for a motorbike is two keep the battery from total discharge when not in use.  This is typically during the winter perhaps a bike destined only to be used on the weekends.  A typical motorbike battery will have a Amp hour (Amp/Hr – a measure of how long it will take to charge) value of between 3 – 5 and a performance version may be up to 9.  This means that a 0.75A trickle charger (the entry models) would take about 7 ½ hours to completely charge a typical battery and 12 for a performance model. 

The above calculations are a gross oversimplification but in essence a trickle charger for a Motorcycle Battery can be 0,75 Amp with no problems.


What type of trickle charger is appropriate for a car battery?

If you have read the bit about motorbikes above then the principles apply for cars as well.  First consider what you need it for?  A specific run down of which trickle charger is appropiate for which situation is at the link.   Is it for a classic car that gets a run out only once every few months in the summer?  In this case you can get a lower power model.  Do you need it for charging a high performance battery (more power) or perhaps lots of car batteries that are likely to be flat (the most power).  In most cases a 1.5 Amp model will be sufficient.