We have had a RideKick trailer for our daughter since 2012. She is a 15 year old brain cancer survivor and has a lightweight Catrike tadpole trike. The RideKick uses a 24v battery. I would like to get another battery. I got my BBS02 and the battery for my bike through Luna and was happy with their service but they don't sell 24v batteries. Where can I purchase a good 24v battery? I would like at least a 20ah. Thanks for any help.
Where to get a good 24v battery?
- Thread starter Xray
- Start date
dogman dan
1 PW
Pingbattery.com still sells 24v lifepo4 I think.
EM3ev does custom batteries, if you want manganese like Sanyo or Panasonic cells.
EM3ev does custom batteries, if you want manganese like Sanyo or Panasonic cells.
chas58
10 kW
BMS battery may be your best bet, if you can handle their lack of customer service:
https://bmsbattery.com/73-24v-battery
Many people here have purchased from elifebikes:
http://www.ebay.com/itm/24V-10AH-HEADWAY-lithium-ebike-bottle-battery-charger-electric-bicycle-/222088656866?hash=item33b583f7e2
or green bike kit:
http://www.greenbikekit.com/24v15ah-lipo-frog.html
Personally, I would start with paul at em3ev.com. I don't know if he has BMS for a 24V system though.
https://bmsbattery.com/73-24v-battery
Many people here have purchased from elifebikes:
http://www.ebay.com/itm/24V-10AH-HEADWAY-lithium-ebike-bottle-battery-charger-electric-bicycle-/222088656866?hash=item33b583f7e2
or green bike kit:
http://www.greenbikekit.com/24v15ah-lipo-frog.html
Personally, I would start with paul at em3ev.com. I don't know if he has BMS for a 24V system though.
chas58
10 kW
dogman dan said:
good point, but
I just had Paul (em3ev) build me a pack that weighed literally 1/3 of what my lifepo4 pack weighs*. that is HUGE! Its like having a new bike!
Maybe not a big deal with 24v, but LiFePo4 isn't the holy grail it once was.
*inspired by spinningmagnets research
cycleops612
10 kW
chas58 said:
thats good input if you have swapped apples for apples ratings wise. Can you be more specific please.
I am going nuts trying to figure why anyone buys li-io 18650s
What about the flat vs slumping discharge rates of the two, 2c vs 1c output mostly, and faster charging can be critical too.
I am too old to be bothered troubleshooting all those cells. The reality is very high odds they will be garbage when a seemingly inevitable problem of any kind arises among that rats nest of 18650 cells & both power and bms connections to all. Not gonna get fixed economically at Oz labor rates, thats for sure.
anyhoo, some details of your swap and impressions would be good
Chalo
100 TW
cycleops612 said:
You mean like Tesla Motors? Yeah I know! You should tell them they're on the wrong track; they could use your help.
cycleops612
10 kW
Chalo said:
yeah, but the context is i am asking, not telling.
And frankly, you couldnt have chosen a worse put down.
Ask yourself if the owners of the worlds largest 18650 fab are going to be in a rush to consider better alternatives for customers, given advances/economies in other formats/chemistries?
wesnewell
100 GW
For ebikes, the answer is simple. Hype, nothing but hype. Personally I only use them in my flashlights. I wouldn't dream of using them on my bike where I want a small powerful battery pack that is easy to maintain. Meaning configurable in minutes without a spot welder and not 100+ possible failure points.
wesnewell
100 GW
I'm wondering how well that Ridekick will perform with 3 lbs of lithium in it to replace 20 lbs of lead. Traction wise.
Chalo
100 TW
wesnewell said:
The solution to that should be 20 lbs. of lithium, shouldn't it?
18650 cells have prevailed for the same reasons AA alkalines have prevailed in the primary battery market: They represent a format whose production is easy to automate, whose packaging is fault tolerant and versatile enough for a wide range of applications, e.g. pocket flashlight to laptop computer to Tesla Model S. Make the cell cheap enough, good enough, and reliable enough, and engineers will design their device to accommodate it.
By having such a large scale of production, they achieve consistency, uniformity, and safety that pouch cells will never match. So like AAs, they'll benefit from more development to improve their performance compared to other cell formats. Check out J/g or W/g figures for AA cells versus C or D cells.
chas58
10 kW
cycleops612 said:
Uh, I read an article or two by spinning magnets?
The newer cells have higher power density and decent C rates.
I then asked Paul to get some higher density cells, and he got Samsung SDI INR18650-32E
36V 9.5Ah (10S3P-32E), 25A BMS, 75*101*130mm, 1.59kg, 340 Whrs
Nice, small, and light weight. Yeah, some 3400mAh or 3500mAh cells would have been nice...
My LiFePo4 weighs 4.5kg, and has the same range on my bike.
If not 18650, then what?
wesnewell
100 GW
Official specifications for samsung 32E
Typical Capacity: 3,200mAh (0.2C, 2.50V discharge)
Minimum Capacity: 3,100mAh (0.2C, 2.50V discharge)
Charging Voltage: 4.2V
Nominal Voltage: 3.65V (0.2C discharge)
Charging Method: CC-CV (constant voltage with limited current)
Charging Current Standard charge: 960mA
Charging Time Standard charge: 5hours
Max. Charge Current: 3,200mA (not for cycle life)
Max. Discharge Current: 6,400mA (for continuous discharge), 9,600mA (not for continuous discharge)
Discharge Cut-off Voltage: 2.50V
Cycle life: 500 cycles to 70% with 3200mA discharge, 300 cycles with 6200mA discharge.
Cell Weight: 50g max
Cell Dimension: Height : 65.2mm max, Diameter(max.) : Ø 18.50 mm
Operating Temperature (Cell Surface Temperature): Charge : 0 to 45°C, Discharge : -20 to 60°C
Storage Temperature: 1 year : -20~25°C, 3 months : -20~45°C, 1 month : -20~60°C
These are crap. Just look at the specs. A whopping 2C cell with reduced life cycle.
What else you ask.
Typical Capacity: 3,200mAh (0.2C, 2.50V discharge)
Minimum Capacity: 3,100mAh (0.2C, 2.50V discharge)
Charging Voltage: 4.2V
Nominal Voltage: 3.65V (0.2C discharge)
Charging Method: CC-CV (constant voltage with limited current)
Charging Current Standard charge: 960mA
Charging Time Standard charge: 5hours
Max. Charge Current: 3,200mA (not for cycle life)
Max. Discharge Current: 6,400mA (for continuous discharge), 9,600mA (not for continuous discharge)
Discharge Cut-off Voltage: 2.50V
Cycle life: 500 cycles to 70% with 3200mA discharge, 300 cycles with 6200mA discharge.
Cell Weight: 50g max
Cell Dimension: Height : 65.2mm max, Diameter(max.) : Ø 18.50 mm
Operating Temperature (Cell Surface Temperature): Charge : 0 to 45°C, Discharge : -20 to 60°C
Storage Temperature: 1 year : -20~25°C, 3 months : -20~45°C, 1 month : -20~60°C
These are crap. Just look at the specs. A whopping 2C cell with reduced life cycle.
What else you ask.
Chalo
100 TW
wesnewell said:
And yet 18650 packs almost always do what we ask them to do, while outlasting Hobbyking toy batteries. Go figure. It's like someone took their properties into account when designing the packs, or something.
chas58
10 kW
wesnewell said:
LOL, you didn't answer my question. What would you recommend? I'm interested in to what you can add to the conversation.
Wes, I didn't make this pack for you. I don't need more than 2C. They meet my needs. There are plenty of 18650 that will give more (like 10A or 20A) if that is what you need, just ask Ron.
Its no surprise that people here have different needs.
Me, I need a <30lb bike that can do 25mph for 25 miles. One with batteries that are simple, easy and safe. That is my criteria.
cycleops612
10 kW
chas58 said:
as you say, each to his own, but that discharge chart is what i have now, and i hate it.
its just no fun the bike getting weaker and weaker. I wouldnt get that on lifepo4 - voltage and current are ~steady. 18650s are lightweight in more ways than one? comparing a 10ah 18650 pak 10 a 10ah lifepo4 ismt fair.
add in the bottom 20% of the 18650s capacity is useless and usually barred from use? ~certainly it seems, if left empty for long, damage results
I am not being narky, I would love to see your bike. can you post some snaps please. i did look a bit on u account, but no joy.
Respect on the results you get. 30lbs and 25 miles is great.
wesnewell
100 GW
That's just pure BS. Ok, I have a 10ah 888wh 88.8V pack rated for a 200A output that weighs~ 14 lbs, So far I've got 15K+ miles on it after ~4 years. Last cost of this pack was $180 on sale. Now find me a 10ah 88.8V 18650 pack with even half the amp rating of that for anywhere close to that price. Waiting!!!Chalo said:
wesnewell
100 GW
Good luck with that. Hope you have lots of money.chas58 said:
http://roadcyclinguk.com/gear/eight-of-the-lightest-road-bikes-for-2016.html#iw2HkSgOYos9GMp3.97
Chalo
100 TW
wesnewell said:
Apples to apples, please. Hobbyking packs don't include any kind of BMS, balance, protection, or charging circuitry. Before you can make cost comparisons, you have to include all those things with your toy pack.
And then you should factor in their short cycle and shelf life, their total lack of physical protection, and their tendency to catch fire.
It's not a bargain. Neither is a Walmart BSO. But you're too dense to figure that out.
wesnewell
100 GW
I've been running fine without a bms for 5+ years. Rc lipo has a better cycle life than 18650's used at the same discharge rates. Those not so cheap li-ion packs wouldn't last near as long as a cheap rc lipo pack of the same size. Most of them won't even work on a 40A controller without hitting BMS lvc. As for charging, sure a 15ah 48V weak 18650 pack comes with a weak charger that will take 4-10 hours to charge the pack. So let's see. It cost ~$500. My 20ah 44.4V pack cost $180. There's a one time cost for charging equipment. How many charging setups you think I can buy for $320?
"Walmart BSO" Are you really not smart enough to realize Walmart doesn't manufacture bicycles? They just sell bikes made by other companies, just like any bike shop does. Yes, I realize you have a vested interest in trying to put down the competition. And you seem to have no shame in doing it wherever you can, even though we both know it's BS too. BTW, I've got ~12K miles on my $99 Walmart BSO (Mongoose Ledge 2.1) up to 61.4 mph and it's still on the road.
"Walmart BSO" Are you really not smart enough to realize Walmart doesn't manufacture bicycles? They just sell bikes made by other companies, just like any bike shop does. Yes, I realize you have a vested interest in trying to put down the competition. And you seem to have no shame in doing it wherever you can, even though we both know it's BS too. BTW, I've got ~12K miles on my $99 Walmart BSO (Mongoose Ledge 2.1) up to 61.4 mph and it's still on the road.
chas58
10 kW
A little off track, aren't we?
Back to the original question:
I don't think LiPo would meet the orginal Poster's requirements.
LiFePo4 would work if weight isn't an issue.
good 18650 cells would be fine for a 24v battery.
We understand that LiPo works great for many of the hobbiests here. And for 99% of the general public, they are a bad idea.
Its nice to have options.
Yep, LiFePo4 has a constant power/speed over its range.
Li-Ion NiCoMn drops off over its range.
I like the full power until dead, but it does cut out unexpectely. Battery capacity monitors don't do much good on those.
Li-Ion NiCoMn at least gives you some warning (either with a volt meter, or simple power output) when I am getting to the limits of my range.
All and all, I like the latter better than suddenly having the battery cut out.
My build is in my signature. I'll have to update that post though with my new work.
I used the mountain bike mostly for the first couple of years, because of the weight of the battery.
But with a light battery, I'm now using the road bike for its speed and range and light weight.
Bikes were in my garage, and two of them were not getting much and were free, or just built with spare parts.
The silver road bike was $600. The original kit and battery were $500. So 25mph + 25miles +25lbs (+3.5lb battery) wasn't too expensive.
Back to the original question:
I don't think LiPo would meet the orginal Poster's requirements.
LiFePo4 would work if weight isn't an issue.
good 18650 cells would be fine for a 24v battery.
We understand that LiPo works great for many of the hobbiests here. And for 99% of the general public, they are a bad idea.
Its nice to have options.
Yep, LiFePo4 has a constant power/speed over its range.
Li-Ion NiCoMn drops off over its range.
I like the full power until dead, but it does cut out unexpectely. Battery capacity monitors don't do much good on those.
Li-Ion NiCoMn at least gives you some warning (either with a volt meter, or simple power output) when I am getting to the limits of my range.
All and all, I like the latter better than suddenly having the battery cut out.
My build is in my signature. I'll have to update that post though with my new work.
I used the mountain bike mostly for the first couple of years, because of the weight of the battery.
But with a light battery, I'm now using the road bike for its speed and range and light weight.
Bikes were in my garage, and two of them were not getting much and were free, or just built with spare parts.
The silver road bike was $600. The original kit and battery were $500. So 25mph + 25miles +25lbs (+3.5lb battery) wasn't too expensive.
That can be true of other cells too, depending on the BMS used as much as the cells.cycleops612 said:
Also, 18650 is just a cell format. Not a chemistry. it is also used for LiFePO4; I used to have a Vpower/cammycc pack of 18650 LiFePO4, until it was stolen. If you're interested in it's performance/internals/etc., you can look up it's repair thread from when I first got it (well-used) a few years ago, with the VPower and CammyCC in the title.
cycleops612
10 kW
amberwolf said:
good input, ta, yeah, naughtily imprecise of me i spose, e.g. you cant believe a word of chinese product descriptions, they seem to use terms they dont understand, randomly - lipo/lifepo4 e.g
more correctly: 18650 format (which varies), limn? canister cells, but what can one do? when in rome...
a bugaboo of mine also tho, is the restrictive format. I love using the bare number of lifepo4 pouch cells needed to attain desired voltage, and then just pick any~ size cell you like to get desired capacity.
That, I may have a chance of diagnosing and fixing myself.
I also trust~ noname makers to get the much simpler manufacture right, and this seems born out, anecdotally.
(lies, damned lies and chinese 18650 specs
)less risk of being cheated i suppose.
i dont think 18650 format has the volume for lifepo4 to be effective, lifepo4 chemistry lags in the storage/volume metric. Not much squirt in each 18650 lifepo4 cell.
We had the lithium battery from the start not the SLA. It will definitely spin the wheel. I think my daughter enjoys doing it. Fortunately she and her trike are light enough it still works well. The only time we had an issue was climbing a 20% hill in wet conditions. Even then, it was more because she started out too slow trying to ride with non-ebikes.wesnewell said:
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