Amped Bike kit and 12ah 36v LifePo4 - acceptable combo?

[Bohh]

Hi all,

Can someone explain to me how you decide if a battery is strong enough to hold up to a specific motor and esc combo? I'm looking into the 12ah 36v LifePo4 packs, and am unsure if they are sufficient.

Thank you

 

[JinbaIttai]

What do you mean by sufficient? What kind of elevation changes will you encounter when you ride, and what kinds of distances? I have an ampedbikes kit on order and I have a 36v 12ah lifepo4.

 

[dogman dan]

Li Pings Lifepo4? A little light in my opinion. More better for a 300 watt bike. What is the wattage of the amped controller? I have the 35 amp WE controller and my Ping 1.0 can put out 20 amps safely. Most ebikes pull around 12 amps when running full speed on the flat. I figure some of my ride exceeds the 20 amps but not all of it. For you, when you pull 20 amps or so starting, or hill climbing, you will be farther above the safe zone for discharge rate.

Will it cut out? Some folks had problems with 10 amp batteries (10ah) and fewer with 15's. If you live in real flat territory you should be ok, if you live in hills, no. Either way, under 20 ah duct tape batteries get stressed more than 20 ah or larger. So the stressed battery can't possibly deliver the same number of discharge cycles. Depending on how you use the bike, maybe who cares? If you will ride 10 or more discharges a week, it could cost ya. If you will ride 3 or 4 charges a week, you will never get to the point where number of discharges matters.

 

[dogman dan]

I'm not sure If I am clarifying or confusing. On the battery specs you see rated discharge rate, continuous discharge rate, and max rate. The test for battery life, is done at, I think, the rated discharge rate. Makes sense to me that you exceed the test rate, and you get less cycles. I could be wrong, but I think buying a battery that you won't much exceed the rated rate is the cheapest way to go. At least for me it should be, since I expect to do 1000 cycles in under 3 years.

 

[johnrobholmes]

I try and choose batteries that will not see burst rates exceeding the continuous rating of the battery. Terrain, gearing (or lack of), motor, vehicle weight, and throttle hand will determine the max amperage you will use.

 

[Bohh]

What do you mean by sufficient? What kind of elevation changes will you encounter when you ride, and what kinds of distances? I have an ampedbikes kit on order and I have a 36v 12ah lifepo4.

I've read that if you have a "weak" battery, it can ruin them. I just don't want it to be ruined.

I live in a relatively flat area. I talked to Danny and he said the max I'll see is 19 amps. The battery is within that range as Max Cont. Current.

 

[dogman dan]

Yes it is, and you will find that the test results that show 1500-3000 cycles are not for max continuous rate. As long as you know that, go for it. No whining if the battery only goes half that many cycles though. I may be wrong, but I belive the rated amps is the 1 c rate. It gets real confusing, but basicly if you can afford the bigger battery, its cheaper on the long run. The smaller battery may suit you much better if funds are that tight now, or your ride is really short. I have about a 25% reserve capacity in my pack and I find I need every watt of it when the wind gets to blowing in my face. Even the big batteries are so small and light, only the price should stop you from buying the big one.