praskal
1 W
I'll have to check the name of the SLA when I get home. I'll let you know in a few hours.
My motor cuts out after 4 miles?
- Thread starter praskal
- Start date
Is it really hilly where you live? If its not then you should take two volt meters and tape them to your handlbars and monitor each 36 volt pack as you ride to see whats really going on if you want to run at this voltage. I know you said you load tested the batts but was it at 40 amps? You should get more range out of it if its flat and you're easy on the throttle. Problem is, with 72 volts, trying to parallel sla's gets too heavy. Be easier with 48 volts or 60 volt as diver did.
praskal
1 W
I have 6 of these UB12120 batteries:
http://www.apexbattery.com/electric-scooter-ub12120-battery-miscellaneous-electric-scooter-batteries.html
It is pretty hill where I live. I still have two blown 72V 20amp controllers. There is a guy who can swap in new mosfets. Maybe I'll have him punch up the mosfets to higher grade ones. The 20amp controller seemed to work fine for longer trips.
I have load tested all batteries, as you guys know. But I don't know how each one does when there is a high load on them like during riding up a hill. I supposed it is possible that one of the batts is bad. Are the UB12120 Batteries any good?
http://www.apexbattery.com/electric-scooter-ub12120-battery-miscellaneous-electric-scooter-batteries.html
It is pretty hill where I live. I still have two blown 72V 20amp controllers. There is a guy who can swap in new mosfets. Maybe I'll have him punch up the mosfets to higher grade ones. The 20amp controller seemed to work fine for longer trips.
I have load tested all batteries, as you guys know. But I don't know how each one does when there is a high load on them like during riding up a hill. I supposed it is possible that one of the batts is bad. Are the UB12120 Batteries any good?
Drunkskunk
100 GW
I pulled the Data sheet for those batteries from the manufacturer. You can find it here :http://www.universalpowergroup.com/specs/D5744.pdf
Basicly, those batterys aren't suited for a 530X motor at all. they would be a bad choice even on a 40X. The voltage drop at just 12 amp draw is bad, and there is no data for any application using more than 1c (12 amps). Usualy a bad sign. So at 40 amps, your 3.5 times the max discharge the company has listed. If you've been able to get 5 amphours of capacity out of them on a 40 amp controller, then good job! but I bet this is your whole problem. They were being pushed way beyond limits on a 20Amp controller, and they are being abused and torchered on a 40 amp.
The off brand 12v10ah I got from Batterys Plus were rated to 20 amps. Still would fail on your bike, but they would give better range and preformance than what you have.
Basicly, those batterys aren't suited for a 530X motor at all. they would be a bad choice even on a 40X. The voltage drop at just 12 amp draw is bad, and there is no data for any application using more than 1c (12 amps). Usualy a bad sign. So at 40 amps, your 3.5 times the max discharge the company has listed. If you've been able to get 5 amphours of capacity out of them on a 40 amp controller, then good job! but I bet this is your whole problem. They were being pushed way beyond limits on a 20Amp controller, and they are being abused and torchered on a 40 amp.
The off brand 12v10ah I got from Batterys Plus were rated to 20 amps. Still would fail on your bike, but they would give better range and preformance than what you have.
vanilla ice
1 MW
Go back to the 20amper until you upgrade your bats. Even at 1c SLA's are only good for about half the ah of their 20 hour rating. I'm running 12a SLA's with a 30 amp controller and they do sag badly. I deal with it by not going wide open until max rpm. I plan to "upgrade" to a 20amp controller at higher voltage though, so that should help. At this point I'd rather run less amps than have to pay for hi-C bats.
safe
1 GW
- Joined
- Dec 22, 2006
- Messages
- 5,681
I've got a lot of experience with the SLA's and can say that you really never want to pull more than 1C current from them. Anything beyond 1C and the Peukert's Effect is so severe (and the sag so excessive) that you waste most of your energy for nothing.
Doing the Math:
12Ah @ 1C = 12 Amps Limit
40 Amp Limit / 12 Amps per C = 3.3C
The absolute short term maximum for SLA is 5C so you are slamming the upper limit of the cells from the first moment you start.
My advice for the "here and now" is to buy NiMh SubC cells because they are rated to be able to pull 10C. Place them in tubes and skip soldering... that's how the RC people do it these days.
http://www.modelelectronicscorp.com/view_products.php?tid=2&stid=4
Doing the Math:12Ah @ 1C = 12 Amps Limit
40 Amp Limit / 12 Amps per C = 3.3C
The absolute short term maximum for SLA is 5C so you are slamming the upper limit of the cells from the first moment you start.
My advice for the "here and now" is to buy NiMh SubC cells because they are rated to be able to pull 10C. Place them in tubes and skip soldering... that's how the RC people do it these days.
http://www.modelelectronicscorp.com/view_products.php?tid=2&stid=4
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