25 March 2010

Understanding Batteries

Batteries in scooters have a high attrition rate! This can however be minimised through an understanding of what it does and how it lives.

I will write about small capacity Scooter batteries (50cc) as they are most prone to failure. The average 50cc scooter runs a very small 4-5amp hr battery in comparison the average small car which runs a 20-30 amp hr battery. The average 50cc scooter when running only creates a usable charge adequate for any sort of re-charge from 50-100% throttle opening. By comparison even a small car with headlights on will create an effective re-charge at idle or above. What this means on the road is you would almost have to ride your 50cc from Cairns to Townsville non-stop at 100% throttle opening to effectively re-charge a flat battery.

The size difference from car to scooter batteries

In an effort to provide owners as much power as possible the Alternator in a 50cc is built as lightly as possible to minimise mechanical drag. A car by comparison charges at a much higher amperage rate (they take into consideration the maximum running load a car may have to provide - stereo, air con, high beam, indicators, and horn all operating at once). This is why a good indication of impending battery failure in a scooter is the horn and indicators doing funny things while at idle – aside from the fact you had to kick start it!

If a scooter is ridden regularly and is in good health ie; starts within 1-2 seconds of cranking the charge rate even on a short run is enough to replenish this depletion.

The battery will generally last at least 18 months to 2 years if it is a good quality maintenance free type, or level checked regularly if maintenance type.

Even sitting on a shelf a fully charged 4-5 amp hr scooter battery will self deplete within 3-4 weeks. Compound this with the inherent current draw of a scooter wiring harness (particularly if it is a Chinese scooter with the good for nothing “it will look good in the brochure” add on bell and whistle security system) and this can be as low as 1-2 weeks. Compound this again with a massive cold cranking effort due to the carburettor drying out and 10-15 seconds worth of engine vacuum alone required to prime the fuel system, the battery will just give up.

Every manufacturer will state in their owners manual that any scooter left for more than 5-7 days should be kick started at this time for this reason, it is also something sales people should stress on the delivery of any new or used scooter but rarely ever is.

If a scooter is used only intermittently (our Navy customers know of this, due to extended sailing times) the best advice is to fit the $65.00-$80.00 smart charger, it is cheaper than a replacement battery and emulates the charging cycle of a routinely ridden scooter. It works as follows; a small set of leads are attached to the battery via the clamp bolts, the lead is then run out through an access to a nondescript location (under body work away from hot or rotational mechanical components), this loose end has a one way male/female plug which has a matching plug which goes by a longer lead to a power pack that plugs in to your 240v house socket. The leads are usually long enough to reach a convenient outlet in the garage. What this unit does when switched and left on is monitor the battery level constantly and charge it as required when the level drops enough (5-10%) it will then turn itself off and stay dormant until again the level drops. These units will generally double the batteries life and it can be fitted to your next scooter and so on.

The Battery Fighter Junior - tried and tested by our Navy customers

A battery will fail primarily due to a powdery substance (Sulphate) which is a chemical by-product of electrolyses (battery discharging/charging). Sulphate collects in the bottom of each battery cell (6 of these in a 12 volt battery) and if left in this state or if the battery was rapidly discharged (see scooters sitting for extended periods) it can then create a dead short between the insulated lead plates inside, this is referred to as “dropping a cell” this is generally an unrecoverable state for a battery and is cause for replacement/disposal, if a battery has discharged over a long period from sitting it may be savable by re-charging using a low amperage deep charge (usually overnight or 12 hours) but every discharge will on average cause an efficiency loss of 5-15% every time.

At ScootaCo we will wet down and charge your battery just prior to delivery, so just like Maccas you are getting the freshest possible battery (that’s maybe not the best analogy), not one that has been sitting on the shelf for six months and by that stage possibly not much better than the one it replaces. We do need at least 30 minutes to allow this so please ring ahead or come back and pick it up after this time, all our batteries are dated the day they are wet down so they can be chronologically monitored.

The ScootaCo promise: Fresh batteries!...

No comments:

Post a Comment

Post a Comment