SLA Battery Help needed

[tomcor33]

I have a Merida PC500 I bought. What are the differences in all the different brands of SLA Batterys? I need 2 12 V 9ah batterys for my bike. Has anyone used the Tempest brand batteries from BatterySpec.com? They seem to have been in business for quite awhile. The prices and shipping charges are the best I found the web.
What is the difference between a UPS replacement battery and a Scooter battery.
Thanks for any help

 

[safe]

http://www.batterymart.com/p-12v-9ah-sealed-lead-acid-battery.html

I bought my batteries from these guys. My guess is that there is not that much difference between SLA batteries, though I'm no expert in comparing them. The most important thing is that small batteries tend to wear out much faster than bigger ones. I've got almost 3,200 miles on mine (38 Ah - 86 lbs total) and they seem to be ready to do a lot more. (no significant wear is noticeable yet) Small SLA batteries that pull more than 1C are sort of doomed to a short life no matter what you do.

What is your maximum current limit in your controller?

The formula is:

Controller Current / Battery Ah = "C" Rating

...so:

30 amp (?) / 9 Ah = 3.3 C

No SLA battery will survive this for very long. 1C is the maximum rate you can run at if you want long life. Your controller would need to be limited to about 10 amps to get long life with these batteries...

 

[Drunkskunk]

I have a Merida PC500 I bought. What are the differences in all the different brands of SLA Batterys?....
What is the difference between a UPS replacement battery and a Scooter battery.
Thanks for any help

A scooter battery has a high drain rate, meaning it can supply a lot of power in a short amount of time.
a UPS battery is ment to sit dorment for long periods of time, and not for putting out a large amount of power.
As safe explained, its all about the drain rate, or the C rating. 1 C means 1 times the Capacity.
A scooter battery should be able to handle 1C constantly, and up to 2c for short periods, like durring acceleration.
A UPS battery might be able to handle 0.1C constant, and short bursts up higher

Since you have a Merida 500, you might look at NiMH batteries instead. you would get better life and range out of the same weight and size battery. I think Merida sells a drop in replacement NiMH. There's also a number of users who have converted to 36 volt NiMH batteries and found it realy improves the bike. From what I understand, the conversion isn't that complicated or expensive.

 

[vanilla ice]

I'm using UPS bats which are AGM just like scooter batteries. I'm using them at 2.5c and they work fine. I'm not sure if they are built the same, but I have a feeling they are.

UPS bats are not designed to run for more than 15 minutes to an hour at a time when at max capacity. If you check out the wattage ratings of un-interruptible power supplies compared with the ratings of their batteries I think you will find they use very high C discharge rates.

I am also using a non-AGM liquid acid motorcycle starter batteries in an escoot and they seem to work fine too. I don't however have enough cycles on any of these things to know about longevity, just know that they are working well for me.

 

[Eric G]

I've never ordered batteries from there,if they're not old stock they ought to be allright.

My only experience is with SLA and find they work well.If you allways pedal while accellerating and ramp up the throttle slowly. You also have to watch how much you drain them.(no less than ~30%drain) Charging them right away after a ride is a must with a good charger (3 or 4 stage).

My last batteries were 3 x 12v/9ah sla and they lasted me ~3 years.They did eventualy die and I replaced them with 7.2ah batts. that very occasionally see a 3.5C discharge for a few seconds. They're still going great and they've just past the 1,150Km mark. I don't expect these batteries to last as long as the previous ones as I've upgraded the motor from 250 watt to 600watt and the controller from 15amp to 25 amp.

I paid 60 dollars CDN for these which at the time were allot cheaper than the other chemistries.

Eric