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Post by dishe on Feb 21, 2007 22:40:36 GMT -5
hey everyone!
I've been MIA lately with the cold weather, but with the temp suddenly back up in the mid 40s, I'm back on the road (at least wherever the snow has melted)!
Now, some of you may recall I always had battery troubles, but as long as I left my float charger on overnight, the scoot woud start right up the folowing day.
well, no more. I went to ride it yesterday and the scoot seems to try then give up with the electric start, but a solid kick or two on the kickstart gets her going.
Very annoying. So I checked the battery with a volt meter figuring the thing probably no longer holds a charge... yet it registered 12.5 volts. I checked again hours later, same thing. Maybe I'm misunderstanding the science behind batteries, but is it possible my trouble comes from the electric starter and not the batt?
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Post by WarrenS on Feb 21, 2007 22:54:07 GMT -5
Thick oil might be making it to hard for the electric starter. Kick start it and run it. Then try starting when warm. If that doesn't do it, it may be the solenoid or starter motor. Also check electrical connections. Be sure they are clean and tight.
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Post by earlwb on Feb 22, 2007 6:50:35 GMT -5
Well based on what you said, your battery is weak and going bad. I don't think it is your starter. Battery Testing can be done in more than one way. The most popular is measurement of specific gravity and battery voltage. To measure specific gravity buy a temperature compensating hydrometer and measure voltage, use a digital D.C. Voltmeter. A good digital load tester may be a good purchase if you need to test batteries sealed batteries. You must first have the battery fully charged. The surface charge must be removed before testing. If the battery has been sitting at least several hours (I prefer at least 12 hours) you may begin testing. To remove surface charge the battery must experience a load of 20 amps for 3 plus minutes. Turning on the headlights (high beam) will do the trick. After turning off the lights you are ready to test the battery. State of Charge Specific Gravity Voltage 12V 6V 100% 1.265 12.7 6.3 *75% 1.225 12.4 6.2 50% 1.190 12.2 6.1 25% 1.155 12.0 6.0 Discharged 1.120 11.9 6.0 *Sulfation of Batteries starts when specific gravity falls below 1.225 or voltage measures less than 12.4 (12v Battery) or 6.2 (6 volt battery). Sulfation hardens the battery plates reducing and eventually destroying the ability of the battery to generate Volts and Amps. Load testing is yet another way of testing a battery. Load test removes amps from a battery much like starting an engine would. A load tester can be purchased at most auto parts stores. Some battery companies label their battery with the amp load for testing. This number is usually 1/2 of the CCA rating. For instance, a 500CCA battery would load test at 250 amps for 15 seconds. A load test can only be performed if the battery is near or at full charge. The results of your testing should be as follows: Hydrometer readings should not vary more than .05 differences between cells. Digital Voltmeters should read as the voltage is shown in this document. The sealed AGM and Gel-Cell battery voltage (full charged) will be slightly higher in the 12.8 to 12.9 ranges. If you have voltage readings in the 10.5 volts range on a charged battery, that indicates a shorted cell. If you have a maintenance free wet cell, the only ways to test are voltmeter and load test. Most of the maintenance free batteries have a built in hydrometer that tells you the condition of 1 cell of 6. You may get a good reading from 1 cell but have a problem with other cells in the battery. When in doubt about battery testing, call the battery manufacturer. Many batteries sold today have a toll free number to call for help. The state of a lead-acid battery can be partly determined by testing its voltage. This test is only accurate if the battery has been disconnected (or switched off) for several hours, preferably 24 or 48. You will need a digital multimeter; an analog one is not precise enough here is another chart: | Voltage of 6V battery | Voltage of 12V battery | Percentage of Charge | Comments | | 6.37 V | 12.73 V | 100% | Good | | 6.31 | 12.62 | 90% | | 6.25 | 12.50 | 80% | Should be charged soon. | | 6.19 | 12.37 | 70% | | 6.12 | 12.24 | 60% | | 6.05 | 12.10 | 50% | | 5.98 | 11.96 | 40% | Must be charged as soon as possible! | | 5.91 | 11.81 |
30% | | 5.83 | 11.66 | 20% | | 5.75 | 11.51 | 10% | Battery is damaged or dead (killed) | | 5.75 | 11.51 | 10% |
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Post by Admin on Feb 22, 2007 9:58:40 GMT -5
Huh?
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Post by earlwb on Feb 22, 2007 10:15:49 GMT -5
Well in my opinion, Dishe had stated that he had charged the battery overnight, and the next day it was only up to 12.5 volts. Then when he tried to use the electric starter it could not crank over the engine enough to get it to start. But the kick starter worked OK.
12.5 volts right after charging, does not sound good at all for the battery.
I thought a chart or two showing approximate voltage readings at different charge levels might be useful.
My apologies for getting too technical. Not enough coffee that early in the morning.
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Post by sussexscooterhead on Feb 22, 2007 10:39:02 GMT -5
Maybe this analogy will help clarify one of the points in Earl's post:
You can think of a battery as being kind of like the gas tank in your scooter or car, and a volt meter as being like the gas gauge.
The gas gauge doesn't tell you how much gas you have in the tank it just tells you if the tank is full or not. So if you have a big tank and the gauge says it's full, you have a lot of gas - but if you have a small tank and it's full, obviously you don't have much gas at all - even though the gauge still says you have a full tank.
Like the gas gauge in a car, a voltmeter doesn't tell you how much energy (gas) there is in the battery.
A battery in good condition is like having a large gas tank, when it's full you have a lot of energy and can do things like crank over the engine with the starter or run the headlights for a long time.
A bad battery, even though the voltmeter might say it's full, doesn't hold much energy - it's like the small gas tank - and so you can't crank over the engine for long if at all.
A load tester gives you some idea of how much energy your battery is capable of holding.
Unfortunately, once your battery looses it's ability to hold energy you can charge it all you want and it still won't start your car or scooter or whatever it happens to be - even though the voltmeter will say it has 12V.
Hopefully that made sense.
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Post by Gary on Feb 22, 2007 12:12:53 GMT -5
I'm sure Dishe did this, but one other thing to check is to make sure the cables are tight. My scoot recently became more and more reluctant to start with the electric starter, and finally would only kick start. I thought the battery was going bad and even began shopping for a replacement. This morning I started to pull the battery out to measure its size, and noticed the positive cable was very loose. I tightened the screw, charged the batt, and sure enough, the scoot fired right up.
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Post by ryan_ott on Feb 22, 2007 17:42:39 GMT -5
The specific gravity is a little different between different companys, Put your volt meter on the battery and if it drops below 10 volts while cranking your battery is weak. 9 and below time for a new battery.
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Post by funderp47 on Feb 22, 2007 19:22:19 GMT -5
You could use jumper cables from another battery or a charger with a cranking (starting) feature and see if it cranks and runs. If it does, your battery is delivering insufficient cranking amps from either becoming weak or not having enough cold cranking amps.
Ryan's method is the simplest. If the voltage drops too low when cranking, the battery can't handle the load.
Auto parts stores have a square analog (needle) type ammeter that has U-shaped cutouts in the back to place around the wire to measure starter current. You have to know normal cranking amps first, but a dramatic rise in cranking amps can signal starter problems. I need to check mine to get a base (normal reading).
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Post by dishe on Feb 26, 2007 11:07:43 GMT -5
Thanks for all the helpful responses! the truth is, I've got a float charger attached with the leads coming out the bottom... its possible that after pulling on it slightlly when attaching the charger all the time I may have loosened the connection on the battery terminals as gary suggested. I hope thats all it is, otherwise it might be time to get a new battery... I'm sure Dishe did this, but one other thing to check is to make sure the cables are tight. My scoot recently became more and more reluctant to start with the electric starter, and finally would only kick start. I thought the battery was going bad and even began shopping for a replacement. This morning I started to pull the battery out to measure its size, and noticed the positive cable was very loose. I tightened the screw, charged the batt, and sure enough, the scoot fired right up. |
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