Battery type for occasional riders

[YoSamES]

I'm battery shopping to get what I need to build my wife's 15 MPH/25KPH bike. Most likely it will be a 36v, 10-15ah. The thought crosses my mind when looking at batteries for $500 and up, sometimes way up, that maybe we don't need such a great battery. She will ride it occasionally during the summer, and there will be several weeks a year when it will get ridden 3 or 4 days a week. Let's say it will be ridden 40 times a year. I think it will die from age, not the number of cycles. Is there a particular chemistry that makes the most sense for this? I think SLA is out simply due to weight, though.

 

[lotrwiz]

i'd say LiFePo4 sounds likea good, safe option, you can get convenient water bottle batteries that are about 9AH 36v, I have one, and it was great till I broke it (my fault though)

just search for 'water bottle battery' and you'll see prices and things, as I'm from the UK I probably can't help much there! good luck.

 

[wesnewell]

I use nothing but RC lipo. It's cheap, reliable, and has the most power of any battery out there. I average 10 miles a day every day. Charge before using. Let sit for months without worrying about self discharge. Got one 4s pack I only use to start my generator. It's been sitting 18 months. I check the voltage about every 6 months. RC lipo has extreme power, so a small 5ah pack may be all you need if she doesn't ride more than 10-15 miles at a time at 15mph. A 12s pack would be best imo. Cost $75-$100 depending on how you configure it. 2 6s packs in series would be the easiest to maintain, but you can get 3 4s packs for $75. It just makes charging a little more trouble. Balamce chargers start at ~$20 for a 50W and go up from there. This is what I recommend for larger 12s packs.
http://www.hobbypartz.com/75p-1220-charger.html?gclid=CNa3z9_N57ICFayPPAod10MAPw
And batteries,
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16207
or these for cheap.
http://www.hobbyking.com/hobbyking/store/__18631__Turnigy_5000mAh_4S1P_14_8v_20C_hardcase_pack_USA_Warehouse_.html

 

[jimw1960]

Something like this would be OK for a low power application like you are needing. I'm assuming round trip commute less than 20 miles and controller limited to 15 amps. Otherwise, upgrade to the 15 amp-hour version. http://www.bmsbattery.com/36v/465-24v-lithium-ion-little-frog-abs-shell-ebike-battery-pack.html


PS: don't take the advice of using RC Lipo unless you really know what you are doing and are willing to take the batteries off the bike and charge in an underground bunker each time, or if you don't mind burning your house down.

 

[wesnewell]

Hmm... Yep, I take mine off the bike to charge, but only because my charger sits on my wooden computer desk and it only takes a few seconds to remove my 880wh pack. Been charging like this for 3 years now and never had a problem. Now, I'm not an idiot with an IQ over 150, so I don't leave it in my garage bulk charging unattended as the only person that I know that had his house burn down did. Handled properly, with reasonable precautions it's very safe. Yep, I've seen the all the youtube fires. I've also seen bikes burnt to the ground that was using lifepo4 batteries too. Any time you use a large battery pack you should know wtf you're doing. If you don't, don't use one at all.

 

[jimw1960]

Yep, I've seen the all the youtube fires. I've also seen bikes burnt to the ground that was using lifepo4 batteries too. Any time you use a large battery pack you should know wtf you're doing. If you don't, don't use one at all.

I'm skeptical of your claim of seeing lifepo4 batteries burning a bike to the ground. Do you have a link to that? Even if a short may cause some smoke in a lifepo4 battery, it will not cause the runaway chain reaction fire that lipo will. Bottom line, lifepo4 with a bms you can leave it on the bike, plug in and forget about it; unplug it the next day and ride. Lipo you either have to be in the same room while it is charging or charge it outside in a bunker or bbq pit or something like that; also, since they do not come with a bms you have to take extreme care to never overdischarge it. It just bugs me when people steer newbies with low power requirement toward lipo.

 

[FeralDog]

SLA lead, can be a good introductory choice for a seldom ridden bike. Low usage, short ranges ... disposable.
IF, you can get them locally cheap enough new {shipping them can be expensive by weight}. Better yet, especially if you can find a good source for used ones (some local industries or warehouses may use them in emergency lighting, etc and give you the old ones free?) . They will need a good rear rack to support them. They are simple as dirt to wire up. Simple to charge. Simple to check voltage, and will last a few years given YOUR criteria. Three 12Ah SLA's will give nominal 36V and weigh about 26 pounds, They will cost around $50(+-) each at a local battery shop. Powersonic is a general brand for reference. The SLA's can be good especially IF you also have another use for them (emergency lighting, ham radio, RC power source, solar, etc , etc)
They are heavy, cheap , and crude ... but they do get the job done.
Strap 26 pounds of anything to a bike, and that is what they will approximately weigh, and that's how they will approximately feel like on the bike.

HK Lipo?
wesnewel makes a very good case!
BUT, those little HK Lipo-devils should come with an Adult Education Class . They need more proper care and feeding than a baby chimp with a flare gun.
They are "touchy". They need some advanced wiring skills to charge (parallel or series) . They will likely need you to make up additional connector's and balance leads (crimping tools and solder). They need little accessories (Cell loggers or voltage alarms; a Lipo safe or ammo cans; or better 12s chargers and Power Supply Units (PSU); and JST-HX stuff and HX stuff, and all sorts of extra little fun stuff , etc).
I think wesnewel is correct when he says "a small 5ah pack may be all you need". BUT you will have to pay very close attention to a lot of numbers with HK Lipos. If you are good with keeping track of numbers in your head, or paper, you can do them if you read a lot on the HK-Lipo subject. You must be ready to take lots of measurement's & readings and lots of special care with them.

IF you choose them, and build and maintain your HK-Lipo pack here on ES (by posting questions and lots of pictures), then HK-Lipo can be a tempting and adventurous choice.

LiFePo4? Relatively considered safer than HK-Lipo for newbies. Also more expensive, and must have a good relationship with a reliable vendor.

 

[wesnewell]

What i think, is that's there are a lot of people hear that just repeat things they've heard about lipo. One has to remember that RC lipo is used by at least a thousand times more people than lifepo4 of or nmc put together. I don't consider them touchy. I've dropped them from 3 ft on to a concrete surface and still used them. I had a bad crash when I hit a big dog that pput me out of commission for a while but my unprotected lipo didn't miss a beat. just lok at my avatar. 6 packs on either side of the top tube taped to my holder. They just need to be secure, although my pack does bounce around a little. You may need to make connectors to connect them to the controller, but you have to do that with any pack. You don't need any additional wiring other than what comes on the packs. You just string them together to get the voltage you want. Less than 30 seconds to make a 12s1p pack. Yep, you need advanced wiring skills to plug one connector into another. This is ridiculous. No tools required. And there's just one accessory I recommend, and that a $5 volt meter to monitor pack voltage while riding.
http://www.ebay.com/itm/Waterproof-Digital-Voltmeter-DC-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-/170846310527
And if you don't really need that if you have your lvc set properly, but it does make an excellent fuel gauge. Cell loggers and voltage alarms are just useless expenses, unless yor blind and can't see the VM or can't tell that your motor stopped running when you hit lvc. There's no numbers to track unless you just want to. The charger will balance charge the pack and beep when it's done. You then just ride and watch the fuel gauge as you would in your cars gas gauge. When it's empty, fill it back up. What a load of crap.

 

[Joppo]

lipos are not so bad as ppl say,i have 4 rc cars, 4 rc planes and 1 rc boat and maby 20 lipos right now. this is a hobby i have been doing maby 12-13 years now and i have NEVER had a lipo fire. all together i think i have owned maby 60 lipos.
i use a 48 v 20 amp lipo for my e bike and im not going back to SLA lead or lifepo4. just dont dropp them on the flore, dont overcharge them, dont let Them stay empty for long time and the most important thing... dont use them if they expand in size. i know it sounds like work to have them, but its really the same things you do with a sla battery only the power is dubble and the waight is a few % of the sla battery.
but in this case maby sla lead is the way to go, think they are the batterys that take the most beating if you do some mistakes, like girlfrieds often do hehe

 

[Cephalotus]

I'm battery shopping to get what I need to build my wife's 15 MPH/25KPH bike. Most likely it will be a 36v, 10-15ah. The thought crosses my mind when looking at batteries for $500 and up, sometimes way up, that maybe we don't need such a great battery. She will ride it occasionally during the summer, and there will be several weeks a year when it will get ridden 3 or 4 days a week. Let's say it will be ridden 40 times a year. I think it will die from age, not the number of cycles. Is there a particular chemistry that makes the most sense for this? I think SLA is out simply due to weight, though.

Sony US18650V3 (LiMn2O4) in a 10s4p to 10s6p Konfiguration. No BMS needed! Store them mostly discharged and cool during winter, charge to 4,1V/cell and discharge to 3,2V/cell and they will last a long time. Price is around 4€/cell over here, weight is 45g/cell.

You also have the advantage that you most likely will not burn down your house with them.

 

[d8veh]

I don't think SLAs would be very suitable because they self-discharge if not used.They're better if you use them regularly. I've given up with LiFePO4 now because they're heavy for their size, so that leaves what the sellers normally call Li-ion,which is LiMnNiCo like the common bottle, rack, seat-post and rack batteries that can all stand relatively long periods of neglect as long as you don't leave them discharged. I use lipos as well,but only when I want a custom voltage. Without a BMS, it's a lot of messing about to charge them, and too easy to damage them.

I don't think that the number of charge cycles is relevant. With regular or irregular use, a modern battery will last at least 3 years, by which time new better batteries will be available, which you''ll probably want to change to. My first lithium battery is still going after nearly 4 years, although it sags a bit more than it used to.

 

[dogman dan]

Sidestepping the lico argurment entirely for the moment, I think the best battery will be the one you can afford, and has a bms, which will still be big enough to power the particular controller on the bike. It doesn't matter if she normally rides slow, you will still pull full amps from every stop sign.

It could be a bottle, or a box, but very likely it will be a type of limn. But it could be lifepo4, depending on prices and your needs. Used that seldom, neither one will likely see 500 cycles before it dies of old age, at 3-4 years.

Whatever you buy, you will need to care for it when it's not in use. Unplug the bms for storage longer than two weeks to a month. For that reason, naked packs with an exposed bms such as a pingbattery can be more convenient.

If not able to unplug the bms, then just keep it topped up. Put it on the charger overnight about every two weeks to keep the pack balanced. You are in Chicago, so charging in a frozen garage should not be done. The battery needs to be above freezing when you charge. And, ideally, when you ride too. So you are likely going to be charging inside the house at least part of the year.

However, if the rides will be really short, it's hard to beat the low cost of an RC lico pack of just 5 ah. But you will have to deal with the possibility of fire by being careful. You are the bms, or you have to install one yourself. A dinged pack can flame, and so can one that had been over discharged at some point. Choosing cheap RC lico means a commitment to being your life depends on it sure you don't do those things.

I don't have a link, since it's from 5-6 years ago on another forum. The lifepo4 fire I remember was a Cushman scooter converted to electric. The battery box had a sharp edge, and cut the wiring resulting in a fire burning up the whole scooter. Any battery that is carelessly installed can short, and burn the vehicle. I had a truck burn in 1977, because a big wire touched the exhaust pipe. Just a 12v short, but it fried the entire engine compartment and dashboard of the truck.

ANY KIND OF BATTERY CAN BURN YOUR BIKE. But it won't happen if you take common sense precautions.

 

[YoSamES]

Re lipos, I'm just too new to this to be messing with them. I definitely see the allure, but I'll pass for now.

OK, so I see various LiMn chemistry labels mentioned. From what Dave said, I've learned that Li-Ion is LiMnNiCo, and Cephalotus mentions LiMn2O4.
Are all of today's "Li-Ion" the same chemistry that Dave mentioned, or are there several flavors being sold as Li-Ion?
What chemistry are the batteries marketed specifically as LiMn? For instance, I'm looking at what is sold by http://www.electricrider.com

The bottom line question: It sounds like any of the LiMn flavors will be good enough for my application. Yes? Or should I be looking at a particular one?

 

[dogman dan]

Li-ion could be anything lithium. Lico, limn types, or lifepo4. And then there are the vendors who will say anything.

Looking closer at the 48v 20 ah pack, it says LiMnCO2 bms included. So presumably that is it. A pack from ER might be a very good choice, avoiding the whole sending your money to china thing.

People make way too big a deal about getting a metal box with the battery. It's just not hard to build a box to carry your battery, or just put something protective around it, and carry it in a bag. An ER limn pack might be small enough to just tuck into a handlebar bag, with some hard protection between the cells and the head tube.

 

[FeralDog]

What i think, is that's there are a lot of people hear that just repeat things they've heard about lipo. One has to remember that RC lipo is used by at least a thousand times more people than lifepo4 of or nmc put together. I don't consider them touchy. .............. You may need to make connectors to connect them to the controller, but you have to do that with any pack. You don't need any additional wiring other than what comes on the packs. You just string them together to get the voltage you want. Less than 30 seconds to make a 12s1p pack. Yep, you need advanced wiring skills to plug one connector into another. This is ridiculous. No tools required. And there's just one accessory I recommend, and that a $5 volt meter to monitor pack voltage while riding.
http://www.ebay.com/itm/Waterproof-Digital-Voltmeter-DC-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-/170846310527
And if you don't really need that if you have your lvc set properly, but it does make an excellent fuel gauge. Cell loggers and voltage alarms are just useless expenses, unless yor blind and can't see the VM or can't tell that your motor stopped running when you hit lvc. There's no numbers to track unless you just want to. The charger will balance charge the pack and beep when it's done. You then just ride and watch the fuel gauge as you would in your cars gas gauge. When it's empty, fill it back up. What a load of crap.

Gee wesnewell, I go and praise your advise, and you call my opinions "crap".
I'll get over it ---- someday
OK wes, I still truly respect your sage-like Lipo advice ... but may I point out some pertinent facts? The recent HK-Lipo shipment I received had a two page "Warning Sheet" enclosed. I guess these extensive Hobbyking Instructions are "crap" and "repeating things they have heard about Lipo's"?
Touchy is the word I used. I did not say highly flammable or even explosive. Touchy cause even a hardcase pack can puff out and crack open its' housing simply because of it being in a too hot car trunk. It can smell like acetone and it is a sign of critical battery failure. Touchy it is when a Lipo has puffed so bad it cracks a hardcase, time to watch-out for that pack?

Connections? You recommended quote "or these for cheap.
http://www.hobbyking.com/hobbyking/stor ... ouse_.html" then you say "This is what I recommend for larger 12s packs.
http://www.hobbypartz.com/75p-1220-char ... PAod10MAPw"

So, can you tell me how in the heck you charge Three 4s 5000mAh packs (12s) with that Thunder 1220 charger without having to make up a new JST-HX harnesses or split the pack (connections) every time? {Thunder 1220 comes with 2 graupner balance lead inputs http://site.hobbypartz.com/image/75P-1220-Charger/75P-1220-Charger-05.jpg, and 3 adapter boards --- I can't figure how that 1220 will even balance those 4s packs series'ed into a 12s 5ah pack without splitting the packs (ie- connections), or using harnesses {or even Paraboards for parallel charge).
Finally, that $5 ebay meter; it is a quick and dirty for voltage readings. They claim "Resolution: 1% +1 digit". I have Four of those meters, checked them against a professionally calibrated Fluke meter , and two of those meters were routinely off spec so much I would not trust them to check a Lipo for accurate LVC. IMHO, that cheap meter needs to be cross-checked for accuracy against a better standard before trusting it.

@wesnewell, I honestly admire your experience and advice on the Lipo's. You are far more experienced in their use than I am. But I find they are touchy, and they need accessories, and they need intelligent connections. THAT is beyond many newbies without extensive study and experience with them. :wink:

 

[wesnewell]

Yes, if you want to use 4s packs, you'll need to make an adapter balance harness to balance charge at 12s. It's a pita to make, but not hard at all. Just takes a little time. And you only have to make one. You can then use 4s parallel cables to it, You can avoid this buying 6s packs. With them you don't have to make anything. I've explained this before. I found I saved enough with my 12 4s packs to make it worthwhile. 12 4s packs was under $275 when I bought mine. 8 6s packs was ~$400, so it was worth it to me.
Yep, the cheap meters aren't very accurate, but they still serve the purpose. Just remember they will usually read a little high and adjust your thinking when using them for a fuel gauge. Mine reads ~2V high at 100V, so I stop at 90V instead of 88V. Doesn't seem that hard to remember to me. You don't use them for charging accuracy. That's what the charger is for.
I will agreee that one should do extensive research before using any battery pack. Pretty much all you need to know can be found in these 2 links.
http://www.rchelicopterfun.com/rc-lipo-batteries.html
http://scriptasylum.com/rc_speed/lipo.html
I can't recall if I ever read the HK warning sheets, but I'm sure it's the standard cya liability warning so if anything happens they're covered. Know your battery and use common sense as you would with gas you put in your lawnmower.
Like RC toys, the bike has limited space. With RC lipo you can get a lot more power on the bike in that limited space.

 

[Cephalotus]

OK, so I see various LiMn chemistry labels mentioned. From what Dave said, I've learned that Li-Ion is LiMnNiCo, and Cephalotus mentions LiMn2O4.
Are all of today's "Li-Ion" the same chemistry that Dave mentioned, or are there several flavors being sold as Li-Ion?
What chemistry are the batteries marketed specifically as LiMn? For instance, I'm looking at what is sold by http://www.electricrider.com

The bottom line question: It sounds like any of the LiMn flavors will be good enough for my application. Yes? Or should I be looking at a particular one?

LiMn = LiMn2O4 (or at least should be, sometimes people call other cell chemistries LiMn).

The most popular cells are those from Sony (US18650V...) that have been namend "Konion" by RC enthusiasts. There are some other manufacturers of LiMn2O4 cells like Sanyo/Panasonic UR18650E.

they are not popular here (I don't know why) but very popular in the ebike community in Germany.

Sony Konion cells don#t have ultra high discharge rates (but they are good), they don't have ultra high capacity (but they are quite good) and they don't lastvfoever (but the are quitegood).

Keep them between 3,2V and 4,1V and they should be fine for 500-1000 cycles. Store them cool and below 3,8V and they will last 10 years.

You don't hage to worry about ab BMS, because those are the only cells that simply don't need one. You don't need to worry about self dischrage, because with those cells self discharge simply does not exist. You can store them for 5 years, if you like so.

Just keep them above 3,2V/cells (2,0V or even 1,5V does not kill the cells, but it will lower life expectancy), keep them below 4,1V (you can use 4,2V but that cuts cycle life in half) and this is it.

They only method to kill them is to get them to hot during soldering, so buy packs from someone qho connects them professionally. Add balancing cables to messure cell voltage, if you like to do so from time to time, but it is not needed.

bionX used these cells without a BMS in their batteries, Bosch sold millions of power tools with these cells without a BMS.

And the best thing: They are quite cheap.

LiFePO4 weights 2 times more than LiMn2O4 and costs more and you need a BMS. LiPolys offer high power, but they have to be babied and monitored and you have to become a battery expert if you don't want to have the risk of fire. If the electronic of the BMS fails or a cable disconnects and you don't recognise it you may have a problem... Some last long, others don't.
LiNiCo(Al)Mn chemistries (from consumer electronics) have higher eneregy density, but suck at high power and/or low temperatures and they also need a BMS...

"The best" chemistry does not exist, every chemistry offers advanatges and disadvanatges, so you have to chose what suit your needs or tzhe needs of your wife.

Does she wnat to become an expert in battery managemnet and wants to have ultra high power and accepts the risk of fire -> Buy lipo
If you want you battery to last for 3.000 cycles and you don't mind the weight and the cost -> buy the best LiFePO4 available (don't buy the cheap ones)
If you want super high energy density and you are willing to pay for it and if you don't need high power, buy LiCoNi(Al)Mn cells

If you are happy with moderate power, moderate cycle life time and if you want a reasonable cheap and care free battery -> I would recommend Sony "Konion" LiMn2O4 cells. US18650VTC4 for high power and long lifetime, US18650V3 for less money. Don't solder them yourself, if you don't exactly know, what to do, buy them from someone who does this professionally. This is money very well spent.

My parents use Bosch multitools with "Konion" battery packs that are quite heavily abused in an electric law mower and are now 6-7 years old. Those cells have never seen a BMS or any other "maintenance", they are stored on the shelf during winter and they are still perfectly good.

 

[YoSamES]

Cephalotus, who sells those Konion cells made up into a battery?
Thanks.

 

[Cephalotus]

I can only name some companies from Germany, because that's where I buy from. But I have no doubt that there are battery manufacturers, that sell ready to use battery packs in the US.

http://www.groetech.de/index.php?main_page=index&cPath=24&sort=20a&page=2
http://www.linergy-shop.de/index.php?cat=c23_Akkutechnik-Akkutechnik.html
http://www.greenroad.at/shop/Akkupacks

 

[FeralDog]

@YoSamES --- It should be engraved on the front page of this ES forum "Batteries Are An Endless Bitch" .
What flavor you pick today, will likely be out-of-favor next year.
{There is rumored to be a special room in the psych-wards for e-bikers who are looking for the perfect battery.}
Get simple, safe, and not too cheap --- not too expensive. Just read as much as you can here, sift out what you think is falderal, then throw your money down and buy your tickey take your chancy.
It is a twisted Goldilocks Quicksand Syndrome of battery purchasing : we are always in pursuit of the batteries that are "just right" . One size does not fit all, and our mileage does vary.

@wesnewell ---- OT ---- Since you mentioned the "you'll need to make an adapter balance harness to balance charge at 12s. It's a pita to make, but not hard at all. Just takes a little time. And you only have to make one"
Do you have a picture, or a diagram of this to add to the pool of Lipo knowledge?
The 14 pin-out on the balance charger, then to 13 pin-out on the adapter board (iMax EH adapter), finally to the 15 pin-outs JST-HX on the 12s1p (three Hobby King 4s bricks balancer leads) can be better shown visually?

 

[wesnewell]

More lipo info.
http://endless-sphere.com/forums/viewtopic.php?f=14&t=39666

 

[23skidoo]

As a Christmas present to yourself, logon to hobby king and get yourself the lipo-powered toy of your choice. Get something with a lipo battery with a JST connector and use the $25 50watt charger. You will soon learn if lipo precautions are feasible for you.

 

[FeralDog]

@wesnewell---Many thanks for those diagrams !!

Sorry to the OP & thread posters for wandering Off Topic.

{ What is happening is a typical "Lipo Battery" mystery that needed unraveling.
Here's a partial summary ---- wes mentioned a combination of decently (cheap) priced HK Lipo Batteries http://www.hobbyking.com/hobbyking/...P_14_8v_20C_hardcase_pack_USA_Warehouse_.html ........ and he referenced a suitable well-priced Thunder 1220 Battery Charger for them http://www.hobbypartz.com/75p-1220-charger.html?gclid=CNa3z9_N57ICFayPPAod10MAPw
BUT ,the Battery Charger (Thunder 1220) Does NOT easily connect to charge those batteries when the batteries are used as 12s (a nominal 44.4volts good for an e-bicycle).
So: the user has to construct their own new wiring harness to get the battery charger to work easily on those HobbyKing well-priced Lipo batteries.
Thus a lesson to the newbies --- do extensive research ! }
Perhaps these fine diagrams could be added to this great "sticky" on RC Lipo series charging tutorial http://endless-sphere.com/forums/viewtopic.php?f=14&t=52240

The Thunder 1220 charger and wires that may come shipped with it --->

 

[999zip999]

A low wattage setup for your wife a lifepo4. Ping. Or ebike.ca, or. Em3 get something worth buying not junk and waste your money, There a lot of junk out there and forget the lipo or lico , hobby king hope me not a fire.

 

[Joppo]

if you dont like SLA then go for the lipos dude, i have used the LiFePO4 in flashlights, e bike, etc and the are not so great for the money, heavy and if one cell get bad.... got a kid who is 5 years old and she charges here own lipo's after driving rc with a smart lipo charger, ofc im home when she do it but like i said they are easy to use and not so dangures as ppl say they are.
thats my advice