battery issues

[deacon]

I am sooooo glad that I stumbled onto the idea of trying the trailer without the battery pack on the bike. I ran the course today and the bike performed much much better. The battery consumption was a little less, but not significantly.

What was different was the weight of the bike. It turned better and seemed to have more power on the flat. I think uphill I might have pedaled a little more, but just a little. Downhill I had to shut the motor off. The push from the trailer was equal to the motor drive or at least darn close.

The other benefit is that I can unhook the trailer and carry it into the house to charge. I can roll the bike into my locked shed instead of trying to maneuver it into my shop. It will make riding it easier.

I did a couple of things to make it more user friendly. I added a safety chain to the trailer so that if the bolt on the hitch breaks the trailer will not just take off.

I also changed the end on the battery charger so that I can just plug it directly into the battery pack. (the male end of an extension cord. Now I can leave the power cord attached to the controller on the bike. I figure the fewer times I take it off and on the bike the longer it will last. I have had to replace the end on the cord once already.

One of the hidden benefits is the looks I get with the trailer. I like being a little different. Why go to all that trouble to be just like everyone else but I can still ride it with hidden batteries.

If you want to make one, I would suggest a trip to the thrift shop for a child's 12" bike. The wheels from it and then the appropriate sized threaded rod should do the trick. I use a piece of conduit as a tongue and an L bracket on the end to tie it to the bike. I have to admit my wheels are from a large scooter. The kids bike is just how I could do it if I were to do it again.

I like this bike more and more as I find ways to personalize it...

ps. this is how it looked today.

 

[toytime]

You know what? You may not be so crazy after all Deacan. Just kidding, I actually like you bike with that little trailer. I am kind of doing the same thing as you with the plugs-ins for your batteries. I use the plugs for trailer hitches lights on cars.
Today I had to go to the post office so I had no choice but to drive my bike with no peddles due to my waiting on parts. I went about three miles all uphill. Near the top of the hill it's one of those hills that make you huff and puff as you near the top. Some even walk it if that gives you any idea. I made it all the way and you could tell she was working like she's never worked before!
These are brand 2 new 12/14 amp batteries and I must say, I was surprised that I made it all the way. So much so that I also passed by the donut shop knowing I'd pass my house and go downhill and have to come back home all uphill again. I made it home with juice left and the motor (my1018) never even felt hot.
I'm thinking that maybe I've learned to respect my bike a little more, having gas may have spoiled me. If I had walked , I'd still be on my way there so the bike pulled through for me.
I was just thinking , your trailer reminds me of an electric wheelchairs drive. If you had a wheelchair you could get 8 hours of use Deacan. 8 hours with the power to climb a tree.
I myself know of one that is sitting out in the backyard, her brother died and she wants $200 for it. It's the scooter with one front wheel.
Just think....8 hours!!!!

 

[deacon]

Is that eight hours at one mile per hour.

PS. I'm mad as a hatter. I'ts my claim to fame...

 

[rearengine]

Deacon!
How about a powered push trailer,or have you tried that already.. Bill

 

[deacon]

It's next on my list of things to do actually.

This afternoon I took the battery trailer for another ride and was again impressed with it. I did a small thing after my ride that will prove to be of great benefit to me. The trailer hitch is held together by as 5/16 bolt which has a nut, which uses a half inch wrench. Of course, I have to search for one every time I hook up the trailer soooo...

I found my oldest and cheapest 1/2" wrench and cut it in half. I rounded off the cut end, then drilled a hole in it. I slipped it onto my keyring. I have to have my keys to unlock the shed where the bike is stored, so I will have a half inch wrench always at hand. I know it doesn't sound like much but it will save me a few steps.

I also finished my trailer pull. Nothing but a rod with a hook on the end. I can snag the trailer hitch with it so that I can maneuver it in and out of the shop without lifting it. Again not such a really big deal but it keeps me from bending soo much.

I think now that I am pretty much satisfied with the bike's battery system.

 

[cvpsmith]

Hey guys! It's been a while since I posted but I happened to be browsing the forums tonight and noticed this thread. Like Deacon, I'm obsessed with range these days. Seeing as I'm about to do some range testing with a 36V LiFePO4 battery, I thought I'd pipe in. Here is my setup:

Phoenix Racer 36V * 40A = 1440 Watt hub motor
Pretty standard Wal-Mart 26in bike
36V 20AH LiFePO4 battery (ebay)

I've hooked up the new battery (20 lbs.exactly, btw.) and tested it. The power seems good. Better than my SLA batteries, which were many months old. No problem hitting 30mph on straight pavement, though I usually try to keep it within 18mph putting around campus (Trivia Question: Can anybody guess from that which campus I'm talking about? )

My commute to campus is 5.144 miles, according to Google. I'll be attempting it tomorrow morning, weather permitting. There are several hills involved, and I'll be staying in the 10-20mph range. I've had problems with my 12AH SLAs giving out on this same route. I did a lot of battery research before deciding on a replacement, and LiFePO4 seemed like the way to go. It was an expensive sucker ($398), but I want something lightweight with better range. BTW, LiFePO4 is also not a cost effective choice for hooking up a lot of smaller cells in series+parallel; trust me, I looked into it!

Anyway, I'll post on my results. I also want to do a maximum range test, but I want to go through the first 20 recharge cycles first as suggested for this type of battery chemistry.

 

[deacon]

I really am curious for a real world assessment of those batteries. If the price comes down to a point they are a real alternative i would love to have a pack. Four bucks for a hobby is out of my range these days. How man amp hours is your pack.

 

[Michigan Mike]

Hey guys! It's been a while since I posted but I happened to be browsing the forums tonight and noticed this thread. Like Deacon, I'm obsessed with range these days. Seeing as I'm about to do some range testing with a 36V LiFePO4 battery, I thought I'd pipe in. Here is my setup:

Phoenix Racer 36V * 40A = 1440 Watt hub motor
Pretty standard Wal-Mart 26in bike
36V 20AH LiFePO4 battery (ebay)

I've hooked up the new battery (20 lbs.exactly, btw.) and tested it. The power seems good. Better than my SLA batteries, which were many months old. No problem hitting 30mph on straight pavement, though I usually try to keep it within 18mph putting around campus (Trivia Question: Can anybody guess from that which campus I'm talking about? )

My commute to campus is 5.144 miles, according to Google. I'll be attempting it tomorrow morning, weather permitting. There are several hills involved, and I'll be staying in the 10-20mph range. I've had problems with my 12AH SLAs giving out on this same route. I did a lot of battery research before deciding on a replacement, and LiFePO4 seemed like the way to go. It was an expensive sucker ($398), but I want something lightweight with better range. BTW, LiFePO4 is also not a cost effective choice for hooking up a lot of smaller cells in series+parallel; trust me, I looked into it!

Anyway, I'll post on my results. I also want to do a maximum range test, but I want to go through the first 20 recharge cycles first as suggested for this type of battery chemistry.

Hi cvpsmith,
Will be anxious to hear about your battery test results. Also what is the life expectency or max recharges of this style battery?
.

 

[cvpsmith]

Hi Deacon,

It's a 20AH pack. The hardest part about forking over 4 big ones was convincing my wife that it would be worth it in the long run for all of the gas that I saved. This sucker better last...

 

[cvpsmith]

Hi cvpsmith,
Will be anxious to hear about your battery test results. Also what is the life expectency or max recharges of this style battery?
.

I've seen a lot of conflicting information regarding this. Here is what was listed on the ebay auction for my battery:

Lifecycle of the whole pack:>85% capacity after 1000 cycles.
Lifecycle of single cell: >85% capacity after 1500 cycles, >70% capacity after 3000 cycles.

I am also interested in long-term real-world results on LiFePO4 lifecycle issues. I think I'll start keeping a log...

--
Paul

 

[deacon]

The log would be a great idea. Keep us posted periodically.

I just came from one of those forums dedicated to E products only. Man those guys start talking batteries, control systems, bms, and stuff like that. It's at that point that I am just get sooo lost.

for pure simplicity I would love to keep my sla batteries. They are cheap simple and require minimal maintenance. Still I guess they will be a problem someday.

Talk about old technology I think I might have saved my lawn tractor batteries enough to experiment with. I'll have to see though.

 

[Michigan Mike]

I've seen a lot of conflicting information regarding this. Here is what was listed on the ebay auction for my battery:

Lifecycle of the whole pack:>85% capacity after 1000 cycles.
Lifecycle of single cell: >85% capacity after 1500 cycles, >70% capacity after 3000 cycles.

I am also interested in long-term real-world results on LiFePO4 lifecycle issues. I think I'll start keeping a log...

--
Paul

Thanks Paul. Lots of conflicting or inconclusive info on batteries out there ... your real life log would be a big help.
.

 

[deacon]

That's a lot of cycles. sounds like about ten years for me. I should live that long.

I got all enthused and worked on my flooded cell lawn tractor batteries. I think i might be able to find two that will hold a full charge, so that I can test them. I would love to know what a flooded cell will do. I think they would work pretty well with a hub motor. The thing that kills most lead acid batteries is the deep discharge or so I hear. My controller shuts the bike down at about half discharge or a little more maybe.

 

[Michigan Mike]

That's a lot of cycles. sounds like about ten years for me. I should live that long.

I got all enthused and worked on my flooded cell lawn tractor batteries. I think i might be able to find two that will hold a full charge, so that I can test them. I would love to know what a flooded cell will do. I think they would work pretty well with a hub motor. The thing that kills most lead acid batteries is the deep discharge or so I hear. My controller shuts the bike down at about half discharge or a little more maybe.

I've been wondering about the flooded cell batteries too. I hear about fishermen using their deep cycle batteries on electric trolling motors for big boats and going all day long on them. Seems like these batteries would be good for bike motors too, even despite their extra weight. ???
.

 

[toytime]

I'm also interested in this. What has stopped me from playing around is the fact that our ebike bats. are in the 20 amp range while boat bats. are in the 100s of amps.
Am I wrong to be afaid of all those amps??

 

[Michigan Mike]

I hope an electrician reads this thread because I'm pretty much clueless.

 

[Michigan Mike]

Surfing another forum for ebikes I came across the link below ... it is VERY HELPFUL in understanding what kind of performance we might expect from different battery types. The section on figuring WATT HOURS shows a lot of promise in helping to determine range on an ebike. Check it out.

Information about Battery Packs

Below is another very helpful site ... looks like the info on these two sites will go a long way in helping to understand and choose the right bike battery.

Deep Cycle Battery FAQ


.

 

[cvpsmith]

That's a lot of cycles. sounds like about ten years for me. I should live that long.

True. But as you've mentioned before, it's the marketing guys doing the math here and their figures tend to be a little north of actual test results...

 

[deacon]

Not to worry about the amps of the battery.. it's the amps the motor draws that determine if it over heats. Think of the battery like a bottle of jack daniels. It can hold a little or a lot it's how much you drink that matters.

The size of the container isn't harmful. I have recently learned that the controller will shut down if the amps get too high, not to mention the fuse blowing. At least it did on my bike. Keep the volts in line and a good inline fuse and you should not have a problem I think.

I will have to figure it out but so far the weight on the trailer (within reason) seems pretty immaterial to the bikes performance. If that is so,. the flooded cell batteries should work out fine that way. I will know more when It stops raining and I can check it out. I have run the trailer with one sla pack and then with two and i saw very, very little difference.

also cca or ca are not the same as amp hours.... I have never found a conversion figure I trust. I read one today that said divide cranking amps by 8 to get ah and they admit that is a very rough estimate. I will know more after the test.

I know the amps on the flooded cell but not the amp hour but I know the ah on the sla batteries and at what point the low battery light came on during my test track rides.

So by riding the flooded cells on the test track I should be able to get a relative guess from the point that the low battery warning comes on while using the flooded cells batteries.

 

[toytime]

So a 24 volt wheelchair battery would take you all day?