Bottle Battery Repair.

[Fish36]

Thanks once again d8veh, a closer look at the Deans connectors and can see they are much better suited for frequent connect/disconnect. Sometimes I'm a bit too much 'belt & braces' when there are simpler/better/lighter options out there so as always your wise advice is much appreciated.

Going on to a totally different topic for a minute if I may, as am nearly there with the battery replacement project. Did think of doing a 2WD drive conversion on it, though to be fair it does what it is meant to do just fine as a very capable and comfortable A-2-B road bike and think I will look in a different direction for my next project...so...

Did I read you had converted a bog-stock mountain bike, a Kraken? Would be really interested to see some pic's if you could point me towards a thread for the project, if it has one?

Am happy to be getting there on road bike renovation though I don't see it as a potential off-roader, waaaaaaaay too heavy. Though the conversion of a light'ish weight MTB sounds interesting Used to be into all the enduro bikes KTM, Honda, Husky etc. though would be happy to be able to do some of that 'green lane' type of stuff on an e-bike...think EddiePJ is doing a great job of really getting out there on his bike and read his threads with great interest and it reminds me what am missing!

Those Haibike's look amazing and the Kudos Eiger seems very well spec'd and capable, and very tempting!...though plenty of great MTB's for sale on that well known auction site just waiting to be converted once the budget allows.

 

[Deleted member 4366]

I've done two Krakens. The first was done jointly with Saneagle (my neighbour). It has a single 500w Bafang CST motor. The other is my own older version with three motors and two-wheel drive. It's got to be the fastest accelerating ebike ever. 30 amps and 64v in the front BPM motor; 30 amps and 64v in the rear 500w Xofo motor; and 22 amps at 48v in the middle GNG motor. The weight is less than 35kg. The battery gives 4.9kw on take off. Ask if you have any questions.

Saneagle's bike (now sold):



Mine - waiting for the next hill-climb challenge:

 

[Fish36]

Wow! They are both very impressive conversions...if you do use the 3-motored beast again in anger please let me know where the hill climb challenge is as I will do my best to be there, would love to see that bike in action...4.9KW is some serious take-off power!

 

[Deleted member 4366]

Hopefully, the Bristol show - if they do the open hill-climb again (May or June). It crashed out last year when the back-wheel overtook the front. I''ve now got wide sticky tyres for it to keep the wheels in line.

 

[El Champiero]

I'll be watching you guys then - the venue is only a few minutes from where I live!

 

[Fish36]

Hehe, the Bristol event sounds like great fun...a long way from me though if I know it is happening I can do my best to get down there and make a weekend of it

 

[El Champiero]

My Bosch de-restricted and set to Speed 3 mode won't be able to keep up with hub motor power in that competition. Then again, if people were riding up it on non electric bikes I reckon I would have a chance of coming in the top 5

 

[El Champiero]

Bloody hell - just noticed not two motors but 3??!?? d8veh - surely you will be the fastest there?

 

[Deleted member 4366]

Bloody hell - just noticed not two motors but 3??!?? d8veh - surely you will be the fastest there?

If I don't crash!

On take off, the front wheel spins for about 10 meters, and then the GNG gets in its stride with the back motor, which makes the back wheel spin. I need traction control of some sort and launch control.

 

[jackhandy]

Bloody hell - just noticed not two motors but 3??!?? d8veh - surely you will be the fastest there?

It's hard to climb Park Street On yer face - Way too much grip.

When D8veh kissed the tarmac last year, you'd have heard the collective intake of breath in Bath.

It was some tank slapper.

 

[Fish36]

If I don't crash!

On take off, the front wheel spins for about 10 meters, and then the GNG gets in its stride with the back motor, which makes the back wheel spin. I need traction control of some sort and launch control.

Am still smiling at the thought of three drive units and 4.9KW on launch!! No wonder things spin a bit and can get a little unwieldy!

Back to batteries if I may please d8veh...is it possible for the 'average' person capable of using a soldering iron and a multimeter (though not much more) to put together a small ah capacity 36v battery pack from readily available in the UK parts? Something cost effective to assemble, safe to charge, compact and with reasonable longevity/charging cycles?

I appreciate that the battery packs are unlikely to have a BMS so am taking it the charger needs to take over this role and therefor must be a bespoke, non-ebike charger?

Something about 5ah would be spot-on. I see this guy on UK Ebay item number 261386759295 regularly selling these though I have no idea what is under the orange plastic and why the packs this particular person advertises are always 'used'. Would much prefer to have a new battery pack, do these packs come from r/c modelling?

Apologies for picking your brains so much though it is obvious you have been there, seen it, tried it, done it and made it work!

 

[Fish36]

It's hard to climb Park Street On yer face - Way too much grip.

When D8veh kissed the tarmac last year, you'd have heard the collective intake of breath in Bath.

It was some tank slapper.

Sounds like it was some sight!!

 

[Deleted member 4366]

Something about 5ah would be spot-on. I see this guy on UK Ebay item number 261386759295 regularly selling these though I have no idea what is under the orange plastic and why the packs this particular person advertises are always 'used'.

Warning! Warning! Warning!

It was one of those batteries that exploded in the night while being charged by one of our forum members. It burst into flames and set light to his garage.

If you want a 5aH pack, get yourself a pair of 5S or 6s lipos. Naturally, with the 6S ones your bike will be 20% faster and more powerful, but the battery will weigh 20% more.

Take your pick:
http://www.hobbyking.co.uk/hobbyking/store/uh_listCategoriesAndProducts.asp?idCategory=86&LiPoConfig=6&sortlist=&CatSortOrder=desc

Most people start with a Imax charger:
http://www.ebay.co.uk/itm/New-iMAX-B6-LCD-Screen-Digital-RC-Lipo-NiMh-Battery-Balance-Charger-/390736695288?pt=UK_ToysGames_RadioControlled_JN&hash=item5af9b8cff8

for which you need a 12v power supply. You can use a pc power supply or one of these:
http://www.ebay.co.uk/itm/AC-Power-Adapter-Adaptor-Transformer-12V-5A-Imax-B5-B6-Balancer-Charger-black-OO-/181287236346?pt=UK_Computing_LaptopAccessories_PowerSupplies&hash=item2a358fb2fa

then you need a voltmeter or wattmeter on your bike, and best to get a couple of lipo alarms too:

http://www.ebay.co.uk/itm/60V-100A-Battery-Balance-LCD-Voltage-Power-Analyzer-Watt-Meter-New-Digital-/171123750032?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item27d7c53490

http://www.ebay.co.uk/itm/Waterproof-Digital-Voltmeter-DC-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-/400413773075?pt=UK_Toys_Games_Outdoor_Toys_Garden_Games_Activities_LE&hash=item5d3a854d13

http://www.ebay.co.uk/itm/RC-Lipo-Battery-Low-Voltage-Tester-1S-8S-Buzzer-Alarm-Checker-Test-LED-Indicator-/330730909870?pt=UK_Sound_Vision_Battery_Testers&hash=item4d011930ae

 

[Fish36]

D8veh, am very appreciative of the very comprehensive reply including very helpful links to the required kits 'parts list', thank you

Am also exceedingly grateful for the warning on the used battery pack as that is exactly the occurrence I would obviously seek to avoid.

Okies, that seems like a potential goer as far as cost and relative simplicity goes, though as you probably expected, a number of newbie questions if I may please?

Charging the assembled pack. Let me see if I can get serial and parallel the correct way around In usage the 2 packs would be serial (double up on voltage though same ah output as one battery?) but for charging they would be parallel as a pair with 2 balance wires plugged in at the same time, or each battery charged totally separately, one at a time?

Does that battery supplier despatch from the UK, or would it be shipping from abroad with potentially higher P&P and some import duties?

Would I need to manufacture anything on a PCB or is it all a case of careful soldering, attaching suitable connectors and just putting the suggested items in the correct place?

Is it better to use 5S or 6S? My current 36v battery pack, though cream-crackered puts out 41+v. It seems 2x6S will do me 44.4v and 2x5S only 37v...with an in-use voltage drop on drawing power and a LVC on my controller of 31.5v, is 2x5S @ 37v going to hit LVC?

I notice the battery packs are spec'd in 'C' ratings (spreads of from/to). This is something I have heard of in passing though know nothing about. Could you please give me an indication of what C 'spread' might be suitable for my standard 36v 250w Bafang hub? Is there a good lay-persons guide to C ratings you would recommend?

As always, your kind input is gratefully received, cheers d8veh

 

[Scimitar]

I see this guy on UK Ebay item number 261386759295 regularly selling these though I have no idea what is under the orange plastic and why the packs this particular person advertises are always 'used'.

Likely re-cycled ancient laptop cells. I wouldn't touch it with a bargepole. I see you have a definitive answer from Dave, but I'm chipping this in to warn others of such dangerous gits. What I find despicable about that seller, is the blithe mention of using them for leccy bikes - "sure, it will be ok, just go get a charger". Now, there's nothing wrong with using an assortment of laptop cells - if you have stripped them out yourself, tested them all, know exactly what state they're in, and matched them into units, then settled on a proper charging regime. Proper DIY, is that.
Even, having done all that, there's no way I would then sell them to the general public and let someone else's house burn down when something goes wrong - that clown is selling them to people who don't know any better and there's one thing you can be sure of - if an old lithium cell is mistreated it will bite you on the bum.

 

[KirstinS]

My tuppence

Totally agree with d8veh - you'd be a fool not to ! Having said that I would rate a hobbyking accucel 6 over the IMAX b6 . They are nigh on identical in everyway except the accucel has active fan to cool and the IMAX relies on passive fins. The IMAX gets very hot and my accucel never does. Price is the same

I have built my own packs from laptop cells but I do it all as scimitar says. I harvest, test and build myself . I get the packs for free from laptop repair shops . A time consuming and strangely satisfying process !! I've become quite addicted and now 18650 cells power all sorts of things from bike lights to iPod docking stations. And I've still got 60 or so lying dormant !!

 

[Deleted member 4366]

You don't need to worry about C ratings of lipos. They can give more current than you'll ever need.

A 36v motor and controller will work with 12S lipos. You just get more power and speed.

You've figured out correctly how to charge and use them. To use them in series, you only need a series connector for the power leads. when you charge them, you have to disconnect the series connector, then you have the choice of charging them one at a time or both together with one of these:
http://www.ebay.co.uk/itm/2-6s-parallel-battery-charging-board-T-Connector-Convenient-LiPo-imax-b6-T5-/400552501663?pt=UK_ToysGames_RadioControlled_JN&hash=item5d42ca219f

Lipos go down very quickly once they reach nominal voltage (36v or 44v). The LVC on your control will stop a 36v pack from going down too far, but you can do it yourself by observing the voltage on a meter instead. The best way though is with a wattmeter, because you can see how many aH you have used. After the first cycle, you'll know how many aH they'll give, so you can easily stay out of the danger zone. A lipo alarm (or two) is your belt and braces. It'll beep if any cell goes into the danger zone, which is useful if you have a duff cell (not common). When you charge the packs,you can see the individual cell voltages.The charger is intelligent,so if you had a duff cell, it would beep and not charge it, but only if you charge one pack at a time. So you can see that there's lots of controls right through. It all sounds complicated, but after a couple of cycles, you'll figure out how it all works and see how the pack is behaving.

One thing you do have to be careful of is not to drop them, which can start them burning. If you ever do drop them, get them out in the open quickly because there's a bit of a delay before they start to burn. It's best to put some protection around them, so that no harm will come if you do drop them. The other main danger is with the connectors. always have a female on the battery side so that no bare pins are exposed, and when you solder on the connectors, always make sure that the one you're not working on is insulated, so that they can't touch. The same applies to any ebike battery, but when you short a lipo, it's even more spectacular: instant vapourised metal.

Once you've got the hang of 12S, you can progress to 14S and 16S to see your motor fly.

 

[Fish36]

Many thanks to d8veh as always for the input, and also Scimitar & KirstinS for your contributions.

The Accucel 6 charger for the extra tenner to gain the fan cooling and cooler operation seems a fair idea, though I really am thankful to d8veh for spec'ing everything at the most affordable level in his post as he knows money is tight for me just now.

Charging the batteries individually sounds like a good way to start then as you say d8veh I can monitor if each individual cell in each pack is 'behaving' then go on to using one of the suggested devices that lets multiple packs be charged at the same time once am happy both packs are all good.

So, the little digital volt display and the higher featured 60V/100A Battery Balance LCD Voltage Power Analyzer Watt Meter are the either/or part of the 'kit'? With the watt meter giving more useful data to understand how the battery pack is being drawn upon during usage and enabling me to learn more about my e-bikes battery usage?

The lipo alarms look like a good investment, and as you know am very much into my 'belt & braces' and as Scimitar mentioned, good DIY is properly done DIY...neat, professional, safe. Do the alarms just plug directly into the balance wire block connector during usage? Then a warning sounds if one cell in either pack starts to fail/have an above average drop in voltage?

Am appreciative of the safety tips on handling lipo packs and also being very wary of bare wires during assembly, thank you. Would foam packing the battery packs with additional foam inbetween them in say a well made Tupperware type box with a secure lid help protect them from drops and bangs adequately? It would make for easy removal of the packs though good protection in use then just slide the box in a pannier?

Using the suggested battery packs sounds pretty straightforward and would give me a much lighter battery pack, much more suited to my planned usage.

If I have the above correct? Just a question on the voltage/watt monitoring please. It looks like the small digital volt display just plugs into the +/- feed then can run a single pair of wires up to the handlebars to keep an eye on things? But if I went with the watt meter it looks like the supply from the battery needs to run into the meter then the output wires from the meter need to go back down to the controller giving a run of 2x pairs of wires along the frame and a much longer length of wiring between the battery and the controller? If am correct in how it all connects up, does this say 3m length of wire from battery to controller via the meter on the handlebars make a difference to battery performance?

Final Q, just on HobbyKing (HK), those batteries direct from the website, would they be despatched from the UK? I notice HK have a shop on Ebay, or at least there is a shop with that name on there selling the same stuff, the prices seem higher (as am sure they would be with Ebays margin on sales) though the shop states the batteries are despatched from the uk.

Once my road bike if back being a happy bunny am still in two minds on my MTB e-bike. Half of me just says get a ready built bike and go and enjoy it...the other half says get a great used high-spec non-ebike MTB and put a kit/package on it yourself and enjoy the assembly process and knowing how everything works Once my knee and finances improve will make my decision and if I go self assembly them what I learn putting together my own battery packs becomes very useful and higher S's may well be interesting to put on the MTB

 

[Deleted member 4366]

The voltmeter just joins to the battery somewhere (2 wires). The wattmeter needs a single thick (14g) black wire to and from it. You don't need to use the thick red out, and you can change the thick red in to a thin one to the battery positive. All the measuring is done on the black wire that carries the battery current. The thick red battery wire can go straight to the controller. I'll draw it uo for you if you want.

Hobbyking lipos come from the UK warehouse. You have to select the UK warehouse at the beginning. The little flags in each listed item shows where it can come from.

The alarms just plug straight into the connectors on the packs. They show in sequence the total brick voltage (6S) and then each cell voltage. They beep when a cell voltage is too low.

 

[Fish36]

Brilliant d8veh, thank you. All understood Just looked on the HK website and see how ordering from the UK warehouse is done now.

Would definately add a battery disconnect switch (one of the heavy duty car battery type ones we chatted earlier in the thread) between the battery and the first red square connector box indicated on your very kindly provided diagram, this would then disconnect positive power flow from everything connected to the battery.

What size of fuse would you suggest please for my installation? The controller indicates a 14amp max for the controller. Would I put the fuse between the battery and the heavy duty switch?