Hello, I'm thinking of replacing my phylion lion battery with an sla setup. My bike has a supposedly a 250 w motor and 36v battery, so a crude calculation gives 7amps as the max current I can expect, so I'm thinking I can use 15 amp Anderson connectors and 16 awg wire? I've seen some other builds online and they use far thicker grades of wire 10awg and such -am I right in thinking these are a bit overkill for the application? Even the 16 awg wire I plan to use seems far more than I really need.

 

Also, I'm thinking of using 3x 12v 10ah sla's and setting them up to charge in parallel with a 12v charger; is there such a thing as an intelligent charger for these sla's with lcd display etc.? Also could anyone recommend a decent source of quality sla's please?

 

Could a kind mod please move this thread into battery faq's please, I seem to have poasted in the wrong section somehow?

Your 250w (nominal) motor will probably draw 15amps or so at peak. You need to build a bit a safety margin in to this as well. 30 amp powerpoles are the best bet.

 

10ah in SLA terms is the equivalent to 5ah of lithium, as you can't fully drain an SLA without harming it. If you are lucky, you'll get 10 miles.

 

These days, SLA does not make sense. They have far fewer charge cycles (perhaps 200), so are a false economy.

 

If you insist, then get ones specifically for electric vehicles. I've used v-batt before, they were good. (edit, can't find their website now, perhaps even they have given up on SLA!)

 

Hope that helps.

Edited February 10, 201511 yr by Alan Quay

14 gauge wire for a 250w to 500w motor from the cbattery to the controller.

 

Probably better not to charge in parallel. It'll take foreever with a 12v charger anyway.

thanks guys, I should have known there would be a downside, I may have to buy a lithium technology battery of some description to do the bulk of the work. I still think I'll build a sla as an extra battery for long trips (there is a town at the end of a local cycle track that is annoyingly just a few miles beyond my range with the 10ah battery I have now -perhaps I'd be better off just buying a higher capacity lithium battery though, depends on the cost)

 

10ah in SLA terms is the equivalent to 5ah of lithium

 

On a good day!

 

Seriously - I have access to far more SLA batteries than I could ever kill in a year on my bike, and I STILL don't use them.

 

Last year, we probably went through 4-600 7AH or 9AH SLA's that are replaced every 2 years. That's not all of them either.

 

Go for a bigger lithium. If you're paying for SLA's, it'll cost you a fortune to keep them up to scratch, and the extra weight you drag along will probably mean you STILL won't make it along the path you mention