Newby McNoob: Ready-made Lipo packs vs LifePo4?

[Beachcruzer]

Hi Team. Long-time lurker, first-time poster. I have a stock beach cruiser with the W.E./Aotema front hub kit and 36V, 12 ah SLA batts. I built it last year and I love it. The only thing I want to change is the batteries. I'm looking at LifePo4 vs Lipo.

First, the mission: Regular runs of 8 miles unassisted on rolling terrain, and the occasional 13-miler. These are round-trip distances from my house to my favorite surf breaks, and the SLA batts can't reliably make it. I'll be dragging my longboard in a lightweight trailer setup (whole thing weighs maybe 20 lbs), and doing this a couple times a week.

Next, about me: I have a two year old and a full-time job. I can wrench and solder as well as the next dude but I emphatically do not want a project. I just want to plug something in, ride to the beach, and go surfing.

Oh, yeah: I want more juice. 48V.

Right now I'm leaning towards Lipo, since at ~100 rides/year I'm not worried too much about cycle life. But ordering all that sh*t from Hong Kong and soldering/duct taping it all together sounds like a project. And I don't want a project. I found some ready-made Lipo packs online, $590 for a 50V, 10 ah pack with BMS and charger (http://www.ebikessf.com/50v10ah-lipo) That's tempting, and since it ships from San Francisco I could have it next week. Anybody had experience with these? And given the 'don't use the whole charge' thing for Lipos, is 10 ah going to handle my 13-mile rt? I'd be a lot more tempted if this reddy-pack came in a 12 or 15 ah version.

Alternative is a 48V, 10 or 15 ah LifePo4 pack from Senor Ping. This would be slightly cheaper if ordered direct, but I don't really want to wait two months to get it. Stateside resellers seem to be a lot more expensive--on par with the Lipo option above.

So . . . what would you guys do in my position?

Thanks, Beachcruzer.

 

[wesnewell]

If you want to go to 48V, then the obvious cheapest way would be just to add another 12ah sla battery to the 36V pack you have now. That should give you 25% more distance than you get now. If you switch to lipo, you don't need a BMS with it, just a charger. A reasonable choice would be four 5ah 6s packs in a 10ah 12s2p configuration. That would be at least equivalent to 20ah 36V sla pack, probably a little more. Putting lipo packs together is no harder than putting sla batteries together. I put my first together using crimp bullet connectors from Walmart that was $1.99 with 14gauge wire and it worked fine. A 12s2p lipo pack will be about the same size and weight as 1 of your 12ah sla batteries. Cost for the pack will be about $200 from HK USA warehouse.
http://www.hobbyking.com/hobbyking/store/__16803__ZIPPY_Flightmax_5000mAh_6S1P_15C_USA_Warehouse_.html

 

[Beachcruzer]

Dammit Wes, looks like I'm starting a project. Just watched Iceman's videos on wiring Lipo and I'm starting to get beyond the mystified stage. The four 6s 5ah solution looks like a winner. That should also give me the option to add two more 6s 5ah packs later if I decide I need 15ah, correct?

I'm reading all kinds of stuff about battery monitors, and warnings about not over charging or over discharging. What is the best piece of equipment to make sure I don't screw this up? Looking for a charger recommendation, as well as the Cycle Analyst or other gizmo(s) to keep me from sucking the packs too low and frying them.

Looks like Zippy is the best brand for the 6s 5ah packs, right? How important is brand choice in that purchase. If they're out of stock should I go ahead and buy something else?

 

[neptronix]

Headway packs may be an option. See what headway headquarters is selling if you can live with the weight / space of a lifepo4 battery like that.

Lipo is a project, and you need to know a lot of things before using it.

Zippy or Turnigy are fairly equal. Zippy batteries have overrated C rates, but stay in balance better. Turnigy have better C rates, but don't stay in balance so well.

 

[wesnewell]

Being able to easily reconfigure a lipo pack is one reason I went with it vs lifepo4 type packs. I've got a 24s pack now I use on 2 bikes. One at 100V, and the other at 48V. For the 48V controller, I just unplug one of the jumpers for 14s, then plug it back for the other bike.
As for monitors, Up to 60V it's hard to beat the $19 price of the HK-010 Power Analyzer. For over 60V I just use a $3 VOM wired to the power leads.
Which charger is a matter of choice and how much money you want to spend on one along with how fast you want to charge. I got a Hyperion 1420I and a 24V 600W psu for ~$200. Could have got by with a $40 setup though. Determine how fast you need to charge your pack and then buy accordingly. A 12s2p pack will have about 500Wh. So a 50W charger will take close to 10 hours to fully charge an empty pack. Do the math and get one that will charge it in the time you want.

 

[dogman dan]

For starters, if you go with ping, or any other battery with a c rate less than 5, get 15 ah.

You'd surely enjoy a 48v 15 ah pingbattery. Your bike, without the longboard, would go 30 mph for about 20 miles. 8)

Is it taking 2 months to get a ping now? I thought it was just about 10 days for him to ship one, and about a week to get to your door. But still, talking arrival in sept. Could take awhile to get lipo too, if you need stuff from the china warehouse. But if you can find the 6s packs at the USA warehouse, you should get em in about a week or less.

12s would be a very very very good option for you, since you'd have so little voltage sag with them, and sooo much smaller and lighter battery. Not so hard to wire up a 12s 10 ah pack at all. But you will have to solder or crimp at least to make a harness to run em in paralell pairs of 6s batteries.

There is a wonderfully reviewed hyperion charger than can do 12s, or just break the series connection and charge with one 6s charger, or better still a pair of them. I really like my setup, using two 150 watt chargers powered by a 350 watt 12v meanwell power supply.

Lastly, just to throw a monkey wrench into the whole thing, you might want to look at a nice battery sold by Chicago Electric Bikes. Small and light, a 36 or 48v 15 ah one would be at least as nice as a ping, nearly as nice as lipo in weight and size, not a project, and ships from Chicago.

I've not really heard though, of much that can beat lifepo4 in terms of cost per ride. My pings are still running fine, one is three and the other one and a half years old. I expect to get years more. But on the other hand, lipo is really nice for the light and small, yet high power. Since you won't need to charge twica a day, I'd say go lipo if you have a reasonably safe place to charge it. Ping if you live in condos or apartments perhaps.

For monitoring lipo, your ride sounds like a voltmeter would do the trick really. But a CA, or cheaper amp meter would be better. The small battery monitors that read out each cell voltage are really good too. If they still have em, the cheap low voltage alarm lights and buzzers can be all you really need. 10 ah of 12s should give you plenty of range. One nice thing about lipo, the RC chargers really do tell you the thing is actually charged. A ping charger has a green light. It tells you the battery is charged. Or it tells you the plug on the charger broke. flip a coin. So you still need a voltmeter to know for sure, with a ping or similar battery.

In the end, you WONT regret the cost of a CA.

 

[joe tomten]

Don't know what John has in stock, but shows 48v 15ahr <$600 incl shipping.

Mine is totally equivalent to my ping.

Plug and play.


http://www.goasisenergy.com/lifepo4_battery

 

[Beachcruzer]

Gentlemen,

Many thanks for the sound advice. LifePo4 sounds like the prudent, conservative and most cost-effective choice, so I am definitely going with Lipo.

My plan now is to get (4) 6s 5ah packs and wire in series then parallel for 12s 2p, giving 44v and 10ah. Icecube inspired me with the modular setup in his YouTube vids, so I'm looking at designing my harness so I can have a two-brick "light pack" at 44v 5 ah, and four-brick "range pack" at 44v 10ah. There's also the possibility to string 'em all together in series for a "speed pack" at 88v 5ah.

That brings up another question: how much voltage will my stock Aotema controller take before blowing up? Pretty sure it'll take 44v, but with all those packs sitting there just waiting to get serial, it won't be long till it sees 66v or 88v, even if just for a spin around the block. Anybody run that much juice through this controller? https://hightekbikes.com/shop/index.php?main_page=product_info&cPath=4&products_id=15&zenid=lspmo3i2dbucsb7j7cppl0r493

 

[jonathanm]

As you can see in the description of the controller, the caps are rated for 63v. So you need to stay under that or get another controller. you can go to 14s lipo with that controller.

 

[Beachcruzer]

So if I push 66v through it, or a little more when the pack is fresh, am I just using up a bit of the generous margin of error or is it likely to blow for sure?

 

[jonathanm]

you're working off 3.7v per cell, right? That's the nominal voltage. Fully charged the cells are 4.2v So an 18s pack will be 75.6v.

 

[wesnewell]

So if I push 66v through it, or a little more when the pack is fresh, am I just using up a bit of the generous margin of error or is it likely to blow for sure?

My new controller has 100V caps and I've put a little over 100V (like 100.2V, 24s) on it, but I wouldn't even think about putting 66V on 63V caps.I've heard of people blowing controllers with 63V caps trying to run 15s (63V). I'm pushing mine, but it only cost $37 so if I blow it, I'll just get another one. Where did you get the 66V figure from anyway?

 

[NeilP]

To give you an idea of range...I use anywhere from 3.5 Ah to 6 Ah/ depending if I am doing flat out or pedalling a bit too. That is for an 8 mile one way trip...pretty flat with a couple of small 100 ft hills and a 300 ft hill at the other end.
That is with a 20Ah LiPo pack at 83 volts, and doing up to 38 mph
So at slower speeds and lower voltage, 10 Ah would get you the 8 mile round trip...but could be cutting it a bit fine if you are towing the board as well. I never thought of towing mine, had left it at a mates then have to walk 3/4 miles with it to the beach.Looks like I need to build myself a trailer

 

[NeilP]

I'd be a lot more tempted if this reddy-pack came in a 12 or 15 ah version.

They do a 15Ah version

http://www.ebikessf.com/50v15ah-lifepo4

 

[Beachcruzer]

Okay, so no playing with 18s until/unless I upgrade the controller. I'll stick with 12s.

Neil, I'll be cruisin at more like 20-25 mph. Rolling blacktop with a little bit of dirt road and sand at the end. I'm pretty confident 10ah will give me the desired range. I'm using the Mule trailer. http://muletransportsystems.com/news_page.html Really cool, minimalist design. I'm toying with the idea of creating an alternative battery mount on the trailer.

BTW, anybody else take their eBike on the beach at low tide? Nothing like a full-moon run on the hard sand.

 

[NeilP]

So 10 should do you...but why take the risk...if you go with the 15 Ah pack then you are not over discharging...try to keep above 80 % discharge at maximum...so already you are down to 8 Ah..go 15..you wont regret it.

 

[wesnewell]

He's going with 12s2p lipo afaik, so discharge rates won't come into play. 10ah of 12s lipo will be more than enough for the range he wants, which is only 13 miles max iirc.

 

[NeilP]

Yea, but towing a trailer...extra weight and drag. If it were me, I would go for the extra capacity now, rather than find that what is bought now is only just enough, and discharging too much and the pack life is shortened. Although we all use the 80% rule if we can ( don't we?) 50% is closer to ideal from what I have been reading yesterday...OK, so you cant believe everything you read...but if it were me I 'd go for a bigger pack, give it an easier life and prolong its life span, rather than buy a lower capacity pack now, screw it in 12 to 18 months or less and have to spend again...

But on the other hand...you will probably find that in 18 months time...packs are cheaper...just my thoughts anyway..I always like to go bigger and better than i need, cause if I only go with just what is adaquate, I usually end up disapointed.

I went for a 5304, a 65 amp controller, and 84 volt 20s LiPo...every one said that was overkill for my commuter run...but now way...if I had gone with anything less I would not have been happy..even now I am sticking an extra 4s on the end to get up to 99 v and the magic 50mph

 

[999zip999]

Yea I take my bike on the bike at low tide So. Co., It like a magic carpet ride some times going to fast to enjoy. I like ebikessf.com Ilia a good man. I went up that and tried his 72v models and liked them. For plug and play I think 50v is a good battery, I would go for 15ah if you can afford it. Are you going up and down the hill to trestels ? Or is it just flat land H.B. like ? Or the hills of Santa Barbra ? Remeber a power supply, a charger, 6 packs to be wire together and a new hobby besides surfing. I see a battery in the ebike general forum about Codd battery in China A123 ? But that's china. Even lifepo4 plug and play needs some soldering.Ilia ( 415-595-6417 ) at ebikessf.com

 

[Beachcruzer]

Guys, I'm planning to order six bricks of 6s 5ah Lipo. I'll use four bricks in a 12s 2p config. This will be my "regular pack." The other two packs (assuming none of the six are runts) will be wired 12s 1p. That will be my "light pack" for very short missions, up to about three miles max. About 80 percent of my ebike trips fall into that category now. For the rare longer trip, I'll have the option to put the smaller pack in parallel with the larger one, for a 12s 3p setup that will give me 15ah. If I get some bad packs, I'll just build the 12s 2p pack, which is probably all I really need.

All this may change once I start using it, but the first step is convincing myself I need more Lipo. Mission accomplished.

 

[jonathanm]

Sounds like a plan. You could go to 14s if you want to get the max out of your controller, but it does require a bit more hassle and a couple of extra little projects. 6s packs is about as plug and play as it gets.

EDIT: I agree about 15ah. I made the mistake of getting too little ah myself. You will regret getting too little at some point but you will not regret getting too much

 

[NeilP]

Have you thought about charging yet?

 

[Beachcruzer]

Zip--Yes, exactly. Going to Trestles from San Clemente, about 8 mi round trip including some hills. My 36v SLA pack handles that hill, so no worries with a stronger pack. The 13-mile rt is to Old Man's. With a 15ah pack I may go all the way to Trails, which is probably close to 20 miles with a serious climb back to the top of the bluff. We'll see.

 

[Beachcruzer]

Yes, I've thought plenty about charging but haven't got a firm handle on it yet. I have a 20mm ammo box that I'll put on the concrete patio, uncovered, to contain the pack while I charge. That should disaster-proof my house. Disaster-proofing the pack is still an open question. Would appreciate advice in this regard.

I've looked at the Hyperion charger, which looks great but very expensive. Another forum member recommended the iCharger106b, which is appealing at less than half the price. I should have plenty of time to charge, so high-amperage charging is not a priority. I'd prefer to charge the whole 12s 2p pack together if that's possible, though a safer and/or cheaper solution that requires me to break down the pack is not out of the question.

 

[jonathanm]

Again.....you will not regret buying the Hyperion, though you may regret buying something cheaper. Not breaking the pack up for charging is something you will really appreciate once you get over the initial sting of the charger price. There are other ways to charge 12s all at once, but you are definitely looking at more projects