After 3.5 months of use and 600+ miles my bike, batteries are slowly losing their endurance. At first it seemed I could go 12-15 miles on a charge ( maybe I was suffering from irrational exuberance) but now after about 7 miles they are pretty well shot. I always charge the pack right after each ride.
Question? Can the pack be revived?
patm0007,
Could you please give us some more information like battery type, number of batteries, configuration (series or parallel). The voltage and amp hour rating of the battery pack along with the size a type of the charger you are using.
Thanks,
Grandpa Chas S.
the Pack: 3 SLA 12v 12 amp/hr in series = 36V , charger : 1.6 amp Top model from ElectricScooterParts.
Motor: 24V running the 24V 10 amp controller at 36v
top speed: about 20-25mph
Bike : wallmart 18 speed
appreciate any input.
Thanks
pat
patm0007,
The first thing I would check is the voltage of each battery. It is not uncommon for this type of configuration to become unbalanced. Charge the pack, when the charger shows a full charge check the voltage of each battery with a voltmeter. Each battery should read the same voltage + or - .1 volt. Most of the people here have changed to bank charging to keep their batteries balanced. This is where you connect a 12-volt charger to each battery so they all get the same charge. In your case you would need 3 12-volt chargers.
Let me know what you find and I can help you some more.
Grandpa Chas S.
Batteries volt:
1) 13.55
2) 13.66
3) 13.86
Could .2 volts really make that much difference.
Is the AGM the brand name, 5P12S A123 ?
thanks for the help
pat
What has the temperature outside done since you noticed your decrease in range?
SLA batteries will loose 40% with a 25 degree F drop in temp.
I am also suffering from a dramatic drop in range because my morning commute is now at 40 degrees F.
My range is a little more than half of what it used to be during the summer.
As soon as the temp gets up to 65 degrees, my range comes back, and the overall performance is better.
Racermike
5 years ago I met Jesus and he total ruined my life. I have never been happier.
Pat,
It looks like you have an unbalanced battery pack and you need to remember the battery pack is only as good as the weakest battery. I would charge each battery to the same level using a 12-volt charger at this point, then ride to check the speed and range. I think you will find the speed returns. If this is the case you need to get 3 12-volt chargers and use bank balancing.
5P12S A123 is a designation for the configuration of the A123 Lithium Ion batteries I am using. It means 5 parallel strings of 12 batteries each. The A123 batteries were taken from the 3.6-volt DeWalt battery packs.
Grandpa Chas S.
thank you for the info, I;ll try charging ea one using my 12v charger.
Yes it is colder now here in FL. That could also be part of the reason for the decreased range.
Thanks,
Pat
after charging each batt with the 12V charger the range improved. 10 miles and still some juice ( not much but some). Guess I will use the 12V charger at least once a month.
Pat,
I may be confused but it sounds like you are still running the scooter at 24-volts and used a 12-volt charger to get both batteries charged up which gave you back your range.
If this is correct then you will need to use the 12-volt charger all the time because the 24-volt charger is not doing the job. These batteries have one real problem, they hate to be in any type of a discharged state. If the 24-volt charger is not getting the batteries up to a full charge this can damage the batteries.
I would buy another 12-volt charger so I could charge both batteries at the same time. Remember these batteries do not like to be in a discharged state for any length of time, so while you are charging one battery the other one is sitting partly discharged and possibly being damaged. Over a very short time, about 2 to 3 months you will only have about half your range if you do not keep these batteries charged.
Grandpa Chas S.
I'm running 3 batt in series using the 36V 1.6 charger from Electricscooter. Also when at work it sits all day not being charge after the 4 mile ride. I will just have to make do and will later uipgrade to a lithium batt.
Thanks for the input
Pat
Start charging at work, for one thing, but the use you are doing should go a lot more cycles that you are getting now. Cold really has an effect. Have you run the batteries all the way down before charging, or charged them every ride? If you run them past 60-70% it does cut the cycle life down, but not as much as you are saying. Maybe you simply got a defective battery. Replacing the runt may be your best bet.
Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global
Pat,
One more item; now that you are running 36-volts you need to replace the 2 older batteries. Lead Acid batteries should always be replaced as a set. The older batteries don't have the capacity of the new battery and they will cause the new battery to work harder and your entire pack will need to be replaced in very short order. Because you bought the scooter used you have no way to know how many cycles are on the original batteries. Charging at work will help but there will still be problems with mismatched batteries in the pack.
Grandpa Chas S.