new ebike build what do you think?

[mrfeelgooddrag26]

if i put a lipo pack hooked up to the electric scooter and i plugged in the charger that goes to the scooter instead of pulling the batteries and using a lipo charging sstem what would happen?

 

[mrfeelgooddrag26]

http://www.hobbyking.com/hobbyking/store/__21384__ZIPPY_Compact_5800mAh_7S_25C_Lipo_Pack.html

http://www.hobbyking.com/hobbyking/store/__15168__HobbyKing_ECO8_150W_7A_8S_Bal_Dis_Cyc_Charger_w_acc_USA_Warehouse_.html

 

[dogman dan]

If you are heading to 14s, that should work. The bargain charger may not be something you will stick with forever, but it will get you going. The charger will need a power supply.

 

[wineboyrider]

DANGER! If your pack of the lipo is higher than the charger than your charger could go pzzztt. Worse yet if you don't have balanced lipos or overcharge them past 4.20 per cell then you can have a lipo fireball!

 

[999zip999]

So where your list ? For success.

 

[d8veh]

You need to read about how to manage lipos. If you don't, and you do what you suggest, there'll be a big bang and your lovely scooter will go up in smoke - possibly taking your house with it. I've seen a couple of small 3S packs go up at a robotics event because they didn't control the charging. The bang was spectacular. Just when the crowd gathered round to see what happened, the second one went off.

 

[Matt Gruber]

it is an open book test. if you blow it up you flunk. 99% of the time the sla charger won't work by itself.
since i want to undercharge, the sla charger is working for me. with a 0-60 minute timer, a DVM for amps,
and another for Volts, both total and individual cells get checked. I use makita tool packs because they, each cell, have a thermal fuse, and there are no reports of fires.
So, No it won't work, BUT, if you do your homework and ace the course, it can work just fine. Along with a single cell charger to bring up any low cells.

 

[dogman dan]

Assuming you have a lead charger, it likely will not be the right voltage. "24v" lead will not charge to the exact same voltage as "24" lithium. There are about 3 major types of lithium voltages as well. So even a lithium charger might still be the wrong voltage.

Since screwing up with RC batteries burns your apartment down with the baby next door included, its just a really BAD idea to just plug in and see what happens.

We know you did it already anyway.

 

[wesnewell]

You can do it safely IF, and those are big if's, the max voltage output (not the rated output) of the charger is no more than the max voltage of the lipo pack, and/or you take certain precautions. I've done it a few times on a 14s lipo pack with a 48V sla charger that had a max output of 60V, but I knew the pack was well balanced and I shut the charger off before reaching the max voltage of the pack. I did forget it once and came very close to max voltage. If you decide to do this, I'd advise you spend $10 for one of those wall timers and make sure you set the timer to go off before you come too close to the packs max voltage. It would probably be a good idea to use some battery medics or other devices that would balance the pack while charging too.. Even with all these precautions, it's still not as safe as using an rc charger that will shut off if a single cell goes over max voltage.

 

[parajared]

I would consider tossing one of these puppies in your cart too, they make balancing multiple batteries way easier. You use it to make 11.8, 17.4 or 23.2 ah packs.
http://www.amazon.com/Parallel-6x-JST-XH-Balance-Adapter/dp/B00CDAPG7M/ref=pd_sim_sbs_e_1

 

[mark5]

I would consider tossing one of these puppies in your cart too, they make balancing multiple batteries way easier. You use it to make 11.8, 17.4 or 23.2 ah packs.
http://www.amazon.com/Parallel-6x-JST-XH-Balance-Adapter/dp/B00CDAPG7M/ref=pd_sim_sbs_e_1

mrfeelgood should read these first if buying the Zippy 7s pack he posted.

Zippy 7s (4s+3s) connectors
http://endless-sphere.com/forums/viewtopic.php?f=14&t=52086
Re: charger for ZIPPY Compact 5000mAh 7S 25C Lipo Pack
http://endless-sphere.com/forums/viewtopic.php?f=14&t=53451#p795446

 

[friendly1uk]

Do you realise you can save about 33% by building with 4s hardcase bricks. So if you were going to buy 4 of them 7s packs, you could go 12s or even 16s with bms and charger for similar money.

10ah 12s is $150 worth of bricks + $25 bms + $30 240w charger + postage = $250
11.6ah 14s using 7s packs is $320 on cells alone.
10ah 16s in bricks is $200 + ~$75 delivered for bms + ~$75 delivered for charger = $350

No way you can use bricks? you can tie them anywhere, they are quite robust.

For me in europe. Ordering from china. 13s makes sense. I'm likely to end up with a King Meter ( http://www.king-meter.com/ ) Display, wanting 48v. If it don't get 48v, The battery meter will not work.

 

[wesnewell]

quote="friendly1uk"]

There are two main approaches. To bms or not to bms. If you research on RC (toy) forums, you will find the picture above. You can string them together on the bike, then take them off again and rearrange them to charge on an rc bench charger of some sort. Then re-arrange them again for the bike. The important thing to be aware of is that the wires from the packs won't simply fit, you have to use conversion boards. It does not seem hard perhaps, but it's this rearranging of the pack that causes nearly all the fires.

Let's put BS to rest. I've been using rc lipo for 3 years. I've never had to take a pack apart to balance charge it. Never. And I run a 10ah 24s2p pack. Takes about 10 seconds to take it off the bike. If I wanted to keep my charger in the garage, I wouldn't even have to remove the pack, but I take inside where I can keep an eye on it while charging. Never leave any battery pack charging where you can't get to it, or in a spot where a fire might cause damge. Both the batteries OR ANY charger may catch fire.
What 24s charger is this? how many wires are you in fact changing?
I charge as 12s with a 14s charger. I don't change any wires, just plugs

Packs built for commercial purposes are different. They can be destined for ev's or backup or whatever, but they won't be done like toys. Instead they leave the batteries and the charger on the bike, and have one box at home. Still 3 boxes, but distributed differently.

No, the charger is not left on the bike in most cases. In fact, it's rare. And to think they are built better is just ridiculous. Most are wrapped with duct tape or shrink wrap.
How it's wrapped up has no relevance, either way people can hash it up. In rc terms, half the charger is left at home, and half on the bike. It's semantics. The bms approach is less boxes. Just one on the bike, and one at home. Just one 2 pin connects them. It's actually better than I said.

It seems like the same thing, because it is. However to disconnect the batteries from the charger is a lot of dangerous work each time. Yet to disconnect the charger from the next box is a simple 2 pin cord.

I guess it all depends on your definition of dangerous. Yep, you could drop the pack on your toes if you're a klutz.
No no no lol, swapping about all them extra wires is why most fires happen. It's not anybody's definition, it is simple fact. Fires are reserved for RC users, and generally after getting the wires wrong. BMS users don't do this swapping about, and therefore non have reported a fire or blowing plugs apart, which is also a fire imo as an electrician.
A spark is just a spark unless it ignites something.

The bms approach means leaving a bit more on the bike. Mine weighs an ounce. It is not really a weight issue. While sat there is does a whole host of other protection duties. Some of which might save you from destroying your expensive batteries, or lighting up the wiring with a short circuit. Most people like the ease of charging their bike with as much fuss as charging their phone. There are many benefits from leaving a circuit board on the bike, and the cost? well it is actually cheaper, because it is the mass market way of doing things.

A 1 ounce BMS. Getting deep in here. And what about the disadvantages? Like the bms ruining your battery pack when left connected for longer periods of time. Or the output limits it will put on your battery pack.
A bms won't ruin your pack. That is one old chestnut. I see lots of posts from users needing packs because there rc system offers no lvc, but no posts about a bms killing a pack. I can leave my pack unused for 6 months and it will be back in balance within 15 mins on the charger. I calculate my tiny 5Ah pack will drop from a storage charge to empty just after they pass there shelf life. It just isn't a problem. Just like a bms puts no limit on how much power you can take by clipping on to the batteries. Yes, that does stop the over currant from working, and the lvc would require a contactor to keep functioning, but as an rc user your happy with lvc being a 99c buzzer anyway. Any sort of disconnection is just added luxury. You still get a cheaper neater package without the extras lost by clipping straight to the batteries.
So what about that 1 once BMS? Want to stick with that? As for LVC, the controller has a built in LVCfor pack level voltages. The BMS's you're hawking has an LVC not designed for rc lipo, but for round LCO chemistry cells that has a lower recommended cutoff voltage than rc lipo. A fact that has been pointed out to you before. So they really don't offer any protection for over discharge of rc lipo. And the BMS draws its power from the battery pack, usually one cell (group). If left connected, in time it will drain that cell or group of cells down. It's just a fact that electronics need power to operate. A BMS is no different. That you haven't seen the post doesn't surprise me. You tend to see only what you want to see. I've laready cover the other disadvantages of using a bms, so won't go over them again.

edit: Remember, Non of the fire threads are from bms users. What is and isn't safe is heavily stacked. That is why no commercial packs come without bms. You can do it differently if you like, but it puts you squarely in the 'at risk' group. All forums have lot of pics showing why you shouldn't stray to toy chargers but still lot of people do. We see many fires each year from this group. Sheds, garages, homes.
I can't state the facts much more clearly

The sky is falling. What a crock. There's been fires caused by BMS wiring reported and documented here. And afaik, there's only been one house fire that was caused by a charger a person was using to bulk charge a huge lipo pack left unattended in his garage. A strict no-no for charging any rc lipo pack, with or without a bms.
We have threads listing catastrophic events by the year. I see no bms users posting. Just lots of wire swappers. If there is indeed a bms related fire, I have not seen it, and it is so outnumbered there is no argument. I would like to see it though, If it does exist. Also, should we be just limiting our talk to 'house' fires, when other fires are important too? Two houses have gone, but the number of other buildings is higher, and just bikes higher still. Your picking house fires to limit results. Well, Limit them to 100% wire swappers.
Again a case of only seeing what you want to see. Another rason you may not have seen it is because you only came here a year ago asking questions.
If you want to hawk bms's, fine. But don't just show the advantages of them. There are just as many disadvantages. And a person needs both to make an informed decision.

Have we merged threads? I don't know how I missed this before. Lovely but so much to address... I have done it in colour above.
No. Just another case of only seeing what you want to see.
Why the 'bs' and the falling skies, crock of shit comments one after another. Are you struggling to present a case that badly? Your almost making this personal. I hope your not offended.
Because you full of more stuffing than a Christmas turkey.
So, these negative points about the bms. Do any exist ? I think your just clutching at straws tbh. Trying to justify what you are doing, when you should really be keeping it to yourself.[/quote]
They've been pointed out many times. I see no need to repeat them. The only real advantage is a simpler charge.

 

[mrfeelgooddrag26]

theres is no 4 batterys its one battery 24 volts theres not enough room to put 4 batteries on this scooter at best theres room for 1 7s pack its basically 4 inches deep and 8 inches wide and maybe 10 inches long where the battery goes so only one lipo battery will fit thus the reason for one 25 volt 7s battery

 

[wesnewell]

You're miscalculating the size by a big margin. You can get at least 6 of those 7s packs in it with room to spare. They're only ~6.2x1.9x2.1", so you could stack them 2 tall and 3 wide easy, so 6 of them will fit. That said, those would not be my choice of packs. That's $0.53 per wh when you can get some as low as $0.32 per wh.