Nano batteries with Tongxin

[Dadplus2]

I have been looking into a battery for my custom build, although to be honest at this stage I'm all ideas but little practical experience trying to learn fast ref electric and the like.

Is it possible to use two of these batteries in series Turnigy nano-tech 4000mah 5S 25~50C Lipo Pack here

Spec:
Capacity: 4000mAh
Voltage: 5S1P / 5 Cell / 18.5V
Discharge: 25C Constant / 50C Burst
Weight: 525g (including wire, plug & case)
Dimensions: 161x49x33mm
Balance Plug: JST-XH
Discharge Plug: 4mm bullet-connector

I want to use on a lightweight assisted pedaling conversion using Tongxin. I'll put the batteries in an SS bottle.

Will post project progress once underway.

Many thanks

 

[oigoi]

I like the idea of your project, are you thinking along the lines of a lightweight bike with a bit of boost for the hills?

I think the question with using this type of battery is how you make sure you don't discharge it too much. The lithium ebike batteries have a battery management circuit that shuts off the battery when it is discharged to a certain point as you mustn't discharge the battery too far or it damages it.
Also how to charge the batteries correctly without overcharging them?

You shouldn't have much trouble finding a controller to work with them so I think it is just controlling the charging / discharging that needs to be considered. There are others on here with more experience than me of this type of thing so it will be interesting to hear their input

 

[Scottyf]

Simple answer is Yes.

Put two in to give you 44v Nominal - 50.2v hot off the charge.

I use a similar setup to keep weight down if only doing a 10mile run or so.
Batteries can easily take the discharge (Although the higher C rates will shorten the battery life)

Charging you can use most Lipo chargers for RC Applications. You can use a 50w charger with an inbuilt charger on this setup but it would take 3 hours to charge from empty.

I dont bother with buzzers or LVC as I always run with ample amperage to cover the distances I travel.
But use a Turnigy Watt meter to check Voltage levels and used total amperes.

This give a rough guide.

 

[amigafan2003]

Yup - I'm going to run 4x5000mah 6s packs on my Tongxin build but I'm putting them in a frame bag and I'm going to run a Lyen controller and set the low voltage cutoff to 36v to protect the packs.

This was my shopping list to put together the pack + charger - all from HobbyKing:-

1x #T200W/11444 Turnigy A-6-10 200W Balance charger & discharger = $38.35
1x #T-20PS/13765 Turnigy T-20Pro Quality 16A Power Supply 180~240V (220W) = $24.99
1x #AM-8014/7879 EC3 Battery Harness 14AWG for 2 Packs in Series = $3.21
2x #AM-8015/7880 EC3 Battery Harness 14AWG for 2 Packs in Parallel = $7.12
1x #EC3-CHG-C/7881 EC3 Charging Cable 16AWG 30cm = $2.72
1x #EC3x10/9625 EC3 plugs (10pairs/set) = $4.94
1x #HKing-6S/7227 Hobby King Battery Monitor 6S = $3.49
4x #Z50006S-15/7639 ZIPPY Flightmax 5000mAh 6S1P 15C = $179.96
1x #PB-XH-EC3/19431 Parallel charging Board for 6 packs 2~6S (EC3) = $9.95

 

[Deleted member 4366]

You would be better sticking to two 5s packs because Tongxins have a reputation for being a bit fragile and are easily damaged by over-volting. Also, the max current would be about 16amps (approx 3C) so you're wasting your money on a 50c pack.
I've been using these for the last 6 months and they work really well and stay in balance very well.
18.5v 5200mAh 20C LiPo 5S 18.5 Volt RC Akku Battery WF | eBay
To monitor your battery voltage while riding, you can use one of these watt-meters and use it as a voltmeter by just connecting the battery to input side. Or you can use it as a watt-meter if you do the remote shunt mod. It's not waterproof, so carry some cling-film if you ride in the rain.
100A Battery Balance Voltage Power Analyzer Watt Meter | eBay

This is the charger that I use that works quite well:
IMAX B6 Digital Battery Balance Charger RC Lipo NiMh 2E | eBay
and you need a 5amp 12v power supply for it:
12V 5A Power Supply Rc Lipo iMAX B6 Balance Charger 937 | eBay

 

[morphix]

I'm really interested in this post and your alternative approach to power.. sheesh, can't believe how light these batteries are, I wish I had known before I bought my 2.5kg 36v 10Ah brick! Dadplus2 What bike are you using for your custom build?

 

[Dadplus2]

Cheers guys, I will continue then and get some bits ordered. I am hopefully sourcing my Tongxin here on the Forum but it may not have its controller so looking at this...

KBS48051,20A,24-48V, Mini Brushless DC Controller here have limited electrical knowledge but think this is the correct one? Can't find any Lyen Controllers out there

Then as mentioned before a custom install into a SS water bottle or this kind of thing above made of Tritan super stong poly plastics type stuff.

 

[Dadplus2]

I'm really interested in this post and your alternative approach to power.. sheesh, can't believe how light these batteries are, I wish I had known before I bought my 2.5kg 36v 10Ah brick! Dadplus2 What bike are you using for your custom build?

I have an old Trek 6000 frame in the garage, I've shot blasted and powder coated it, and I've build to back up with bits off a mid range muddyfox I bought but I'm ditching all the heavy stuff. It now has rigid forks kojak tyres fixed wheel and I'll use front brake with motor cut off only.

If its lightweight I won't need gears (well we'll see how it goes). Lots of ideas very little knowledge!

 

[amigafan2003]

You would be better sticking to two 5s packs because Tongxins have a reputation for being a bit fragile and are easily damaged by over-volting.

Really? My reasearch on Tongxins indicate that it's wattage that damages Tongxins - not amps or volts - so if you keep the peak below about 550 watts then you are ok - i.e. run 36v @ 15amps or 48v @ 11amps and avoid using the throttle from a standstill - wait until about 5mph.

My controller will be limited to 12amps @ 44.4v.

 

[Deleted member 4366]

Can't see a pedal sensor input anywhere in the spec. for that controller Does it have one? Also, not sure what it means by analogue brake inputs. Is that for regen, in which case it might not work with brake switches.

 

[Dadplus2]

OK following that logic if my set up battery output is 37V I need to limit the output through the controller to around 14amps. My controller is rated to 20amps so I need to set it to 70% max motor current.

I'm also looking into whether I can limit battery discharge through the controller to keep the batteries safe, as I believe thats an issue with these batteries. I see I could use an onboard meter but would prefer not to.

 

[NRG]

I agree with d8veh, I would avoid the nano batteries and stick with the standard Turnigy packs and keep the voltage and amps down (36v and 12 amps) with this motor. Also I would add LVC monitoring its a wise precaution and really for the extra cost of adding it, it makes no sense not to...small change for ensuring no over discharge of the cells which can have nasty consequences later on when charging...

Current discharge through these batteries is not a concern, certainly not at 12amps!

 

[amigafan2003]

OK following that logic if my set up battery output is 37V I need to limit the output through the controller to around 14amps. My controller is rated to 20amps so I need to set it to 70% max motor current.

I'm also looking into whether I can limit battery discharge through the controller to keep the batteries safe, as I believe thats an issue with these batteries. I see I could use an onboard meter but would prefer not to.

It's not the discharge rate that's an issue with lipos (even a 15c 5ah lipo can do 75amps!) it's the state of charge - you don't want to take them down by more that 80% (i.e 4ah our of a 5ah) as that's what drastically shortens their life.

 

[Scottyf]

D8veh, the akku lipo you listed they any good?
I read a few reviews that where not particularly inspiring. However it was for rc applications that roast through the discharge process and those packs where not rated that well.

Hence I avoided them. However for brand new packs from hk they are super cheap! And I know that the high discharge rate isn't needed in ebike format.

However they would make a great cheap buy for the next set of lipo.

Morphix I wouldn't worry to much about the lipo battery they can be fiddly sometimes and you end up spending lots on little bits and pieces every now and then and it comes with added hassle and more safety problems.
Least with anbattery and charger from one place you get an all in one solution that's plug and play virtually.

 

[Deleted member 4366]

D8veh, the akku lipo you listed they any good?
I read a few reviews that where not particularly inspiring. However it was for rc applications that roast through the discharge process and those packs where not rated that well.
.

All I can say is that they work extremely swell for me. I used them today for my 29 mile commute and they were still showing 38v when I arrived home. I also have a 44v pack of the same type, but I damaged them by not supporting them properly in a pannier. They bounced against a bolt during a long journey and wore away the corner. Now the damaged half doesn't balance so well, although I can still get about 6 or 7 aH out of them. I suppose I was lucky they didn't catch fire. I now double protect them inside my football boot rack bag.
Incidently, my new Giant NRS BPM is brilliant. The suspension is so supple. It's a real joy to ride and I put the good range down to the potentiometer cruise control, which is set to 12mph - you should get one. The clutch stuck one more time, and I freed it with the hammer again, but it's been OK in the last 50 miles, so I'm hoping it just needed a bit of running in. I have a spare if the worst comes to the worst

 

[Scottyf]

Does sound like a lucky one. Still it's only if they puncture and oxidise it would be a problem I think.
Maybe the hard case ones would be better than the softer pouches for ebike application.

I'll look at investing once my turnigy and zippy packs die. I'm hoping for a good year or two use out of them now.

However for the price I paid I could get 6 of the unbranded ish lipos with lesser c rate but fine for my ebike.

 

[Dadplus2]

I've started building up the bike cobbled together from another bike and some bits, not finished yet the forks will go and some brakes to go on. I've ordered the Tongxin and controller, batteries and charger.

 

[catsnapper]

The Tongxin hubs are compact, quiet and surprisingly good hill climbers for their size, but as amigafan2003 mentioned, trying to start from standstill under power is a bad idea. The resultant juddering and knocking from the hub will ensure you don't try it again!
5-6mph under pedal power before turning on the power is a minimum.

The controllers I had supplied for Tongxin hubs were 36v 6 amp with a 13 amp limit.

I'm a bit doubtful about using S/S with these hubs - if you have the gearing low enough to pull off with pedal power under most conditions, it's going to be too low to be of use at higher speeds - just when pedaling and motor assist are the most fun

An 8spd Alfine hub is an ideal match , especially if a winter commute is a possibility.

 

[Dadplus2]

You may well be right about the single speed thing nice to try it though. I'm now also going to try just a 'boost' type switch with no brake cut-offs. Possibly two of them. Has anyone tried this?

 

[Deleted member 4366]

You may well be right about the single speed thing nice to try it though. I'm now also going to try just a 'boost' type switch with no brake cut-offs. Possibly two of them. Has anyone tried this?

Do it like this and you'll be able to adjust the amount of boost with the pot. Leave off the throttle and substitute a latching push-to-make switch. It's not easy holding a "boost" button for a long time. I'd use at least one brake switch. Get one of those cheapo bike computers off Ebay (about £2); Cut off the sensor at the computer end; Fix the spoke magnet to your brake cable where it runs along the cross-bar; Tie-wrap the sensor to your frame. Now you have a brake switch that allows you to keep your nice brake levers.- if that's why you don't want brake switches.