Hailong HL1 36v Batteries - on/off switch - yes or no?

Cadence

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Feb 23, 2023
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I have three bikes kitted out with Yose Power 36v kits, and until recently they have shared one battery - because I can only ride one bike at once! The battery is a 36v 13Ah HL1, with the 5 gold round pins.


After just over 18 months use and around 800 miles (so just out of warranty) and careful management, the bike started cutting out at around 38v. (display blank and no battery voltage at discharge connector with multi-meter). Switching the battery off and on again the display lit and the multi meter showed 38v and I could continue riding for a short while, then it would cut out again. I tried fully charging and leaving the charger plugged in for about 12 hours and still had the problem. The voltage when fully charged was 41.5v. and the last cut-out occurred at 40 volts. I suspect either a duff cell or faulty BMS. The connector pins are clean with no burn marks.
To solve the problem short-term I bought another battery from Yose Power and I'm in two minds whether to explore the duff battery any further. Part of me says I want to solve the problem and another says "don't mess with things you don't know about!".
It has lead me to look for alternatives for the future. I don't want a different style of battery as all three bikes have the down-tube slider brackets. One of them also has an integrated controller.
Searching around, I find that TBK and GreenBikeKit both offer this type of battery with Panasonic cells. There is also a useful 17Ah version. Only GreenBikeKit do it with the 5 round gold pins, although swapping the connector isn't much of a problem , However........

I notice that neither of these has an on/off switch, unlike the Yose Power version. So how important/essential is such a switch? I'm aware that having the discharge connector live while removing and fitting the battery is likely to cause sparking and I've always been careful to switch it off. I like to charge off the bike and with swapping between bikes I am removing and fitting quite often. Do the batteries supplied by Woosh have a switch? I can't tell from the photos on the website.
So what are people's experiences of using these batteries that don't have a switch? Is it necessary? If not I don't quite understand why Yose Power fit them?
 

Woosh

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the switch is not necessary and it sometimes fails outside the warranty.
The little spark that you see when inserting the battery is taken into account in the design of your controller. If you worry about it, put a smidgen of grease on the contact blades of the battery connector.
 

Cadence

Esteemed Pedelecer
Feb 23, 2023
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201
the switch is not necessary and it sometimes fails outside the warranty.
The little spark that you see when inserting the battery is taken into account in the design of your controller. If you worry about it, put a smidgen of grease on the contact blades of the battery connector.
Thanks for the super-quick reply! I've actually been using silicone (electrical) grease since day one on my connectors. You have prompted a thought though. I might have an intermittent faulty switch, so I could bypass it and see if that solves the problem. Thanks again!
I'll certainly consider Woosh for my next battery. I'd go with your new DP battery but it is just too big for one of my frames.
 

saneagle

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If you're going to leave the battery on the bike, you don't need the switch, but if you're going to take it off more than a few times, you should get one with a switch because if you connect it when switched on, the inrush spark will burn the connector sooner or later. The round pin ones have very thin metal, that easily gets vaporised by the spark. The blade type last a lot longer and aren't so easily damaged because their metal is much thicker.

It's always worth having a look at your old battery. It's very easy to do some simple tests that should be able to point you in the right direction, and there's very little danger doing that.

All you do is unscrew the case and lift the main case off carefully. Every battery is different inside, but hopefully the cell-pack will be left sitting in the half that leaves the BMS accessible.

At that stage, you can follow all the wires from the connector to the BMS to check that they're joined properly.

Next test is to look at the BMS to see where the negative thick black wire from the cell-pack is attached - usually marked "B-", then the thick black going to the connector - usually marked "P-". Measure the voltage at each point using anywhere you can access the thick red as the positive. If there's a difference, the BMS is either switched off or faulty.

The main test is to test the cell-pack voltages in the multipin connector attached to the BMS. Prise it off, then, using the thick black as the ground, measure the voltage on each segment. Write down each one so you can use subtraction to calculate the 10 cell voltages, which is the difference between each adjacent pair. You stick your probe on the little blades on the edge of the connector rather than the pins themselves.

Those tests should give an indication of what's wrong.

Greenlance are a good UK supplier for Hailong type batteries. They're very quick, quite cheap and the guys there are very responsive.
 

Cadence

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Feb 23, 2023
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Thanks Saneagle. I've had the battery open and found the multipin connector. I've put it away again for now as it's not a priority. I might open it up again at some point. I recall that the connector had a black wire at one end and a red wire it the other (white wires in between). What are those for please?
 

thelarkbox

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Aug 23, 2023
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The Switch on a battery is desirable as it allows you to plug in the battery to the bike without a bang/pop and spark as the controller draws an initial load to charge its capacitors (or so I have been told is the cause).

Such pops bangs and sparking can damage the terminal connectors resulting in a less than optimal battery connection and perhaps performance issues as well as making you jump out of your skin each time a switchless battery gets plugged in. Certainly not good for me..

anti-spark xt60 connection blocks are available at a small premium and can be used in many cases to sidestep this issue simply by unplugging the xt60 connection before plugging in the battery, however with a controller embedded within the battery base situation this isnt a feasible solution.

As someone living with this situation (yose-power conversion with battery base controller) and a switchless spare battery.. I would urge you to invest the extra and get a battery fitted with an isolation switch.

Fwiw i cracked my battery to try and add a switch, even tho the bms had an empty labelled solder pad, adding a spst or momentary contact switch had no effect ;( so dont rely on a post buy diy bodge to be an easy fix.
 

saneagle

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Thanks Saneagle. I've had the battery open and found the multipin connector. I've put it away again for now as it's not a priority. I might open it up again at some point. I recall that the connector had a black wire at one end and a red wire it the other (white wires in between). What are those for please?
If there are 11 wires in total, black is ground (0v) and red is total battery voltage. If it's easier, you can put your black probe on the black wire's pin and then the red one on each of the other pins in sequence. If you do that, be very careful not to let your probes touch while in contact with the measuring points.
 

Cadence

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Feb 23, 2023
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Opened up the battery again earlier today after leaving it connected to the charger for a few minutes. It was already showing green. It has always measured 41. something volts hot off the charger, but this time it is only 39.1 - the lowest it has ever been after charging.
Measured the cell voltages using the thick black wire at the BMS and the individual pins on the BMS connector, starting with the black wire at the end:-
0, 4.2, 7.6, 11.8, 16, 20.2, 24.4, 28.6, 32.8, 37, 41.2(red wire).
All even 4.2v steps except between one (3.4v). This suggests to this uneducated explorer that the cell reading 7.6 is too low and thus the battery is out of balance?
If I test using the + pin on the discharge socket and the thick black wire going into the BMS I measure 41.2v, but if I switch to the thick blue wire coming out of the BMS (- going directly to the - on the discharge connector) I only get 39.1v. Is that an indication that there is a BMS fault?
I'm a bit reluctant to start stripping the insulation off the cell pack unless I really have to as I don't want to start soldering wires to any of the cells, so I was was wondering from the above if a replacement BMS would bring the cells back into balance?
 

saneagle

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Opened up the battery again earlier today after leaving it connected to the charger for a few minutes. It was already showing green. It has always measured 41. something volts hot off the charger, but this time it is only 39.1 - the lowest it has ever been after charging.
Measured the cell voltages using the thick black wire at the BMS and the individual pins on the BMS connector, starting with the black wire at the end:-
0, 4.2, 7.6, 11.8, 16, 20.2, 24.4, 28.6, 32.8, 37, 41.2(red wire).
All even 4.2v steps except between one (3.4v). This suggests to this uneducated explorer that the cell reading 7.6 is too low and thus the battery is out of balance?
If I test using the + pin on the discharge socket and the thick black wire going into the BMS I measure 41.2v, but if I switch to the thick blue wire coming out of the BMS (- going directly to the - on the discharge connector) I only get 39.1v. Is that an indication that there is a BMS fault?
I'm a bit reluctant to start stripping the insulation off the cell pack unless I really have to as I don't want to start soldering wires to any of the cells, so I was was wondering from the above if a replacement BMS would bring the cells back into balance?
There are only two ways to get the battery back in balance. Firstly, you can get the BMS to so it by leaving the battery on charge for several hours until that cell is the same as the others. Secondly, you can charge the low cell with a separate single-cell charger.

The differnce between your 39.1v and 41.2v has nothing to do with balancing, as the only thing between them is the bank of output MOSFETS, which are like electronic switches. It's possible that one is a bit faulty, but I don't know enough about them to know any mechanism that would reduce the voltage. We have seen that reported before, and the poster said that it was fixed with a new BMS, though that doesn't necessarily mean that the BMS was faulty.
 

Cadence

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Feb 23, 2023
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Thanks Saneagle. I m must admit I was expecting an out of balance cell, but the difference in the BMS input and output voltage has thrown me somewhat. Yose Power will supply a replacement BMS (£25.00 inc postage) but I'm not sure it will make any difference.
I've already tried leaving on charge for 24 hours after the charger light goes green and it still cut out when discharged to around 38 volts. I'm a bit reluctant to try charging the individual cell as I'm not very confident about it. Is it possible to use a common or garden phone charger, cut the connector off and connect it to the relevant pins on the BMS connector, or would I have to strip the cell pack insulation off and solder wires to the individual cell(s)?
I would obviously have to monitor the charge while doing so and presumably disconnect from the BMS?
 

saneagle

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Thanks Saneagle. I m must admit I was expecting an out of balance cell, but the difference in the BMS input and output voltage has thrown me somewhat. Yose Power will supply a replacement BMS (£25.00 inc postage) but I'm not sure it will make any difference.
I've already tried leaving on charge for 24 hours after the charger light goes green and it still cut out when discharged to around 38 volts. I'm a bit reluctant to try charging the individual cell as I'm not very confident about it. Is it possible to use a common or garden phone charger, cut the connector off and connect it to the relevant pins on the BMS connector, or would I have to strip the cell pack insulation off and solder wires to the individual cell(s)?
I would obviously have to monitor the charge while doing so and presumably disconnect from the BMS?
Yes, you can charge through the pins on the multipin connector. I sometimes solder two wires to two pins of one of these things, which you can break to whatever length or number of pins you want. Check that your pins are the more common 2.5mm pitch, otherwise you have to look for pin header with the matching pitch:

Considering the low cost of balancing. I would do it before I'd buy a new BMS, and you can then test whether the balanced battery works OK, if it doesn't, you can temporarily bridge the B- to the P-, which by-passes the output Mosfets. That'll be OK for one cycle to test whether the problem goes away. If that doesn't solve it, there's a cell problem, so no point in wasting money on a new BMS.
 

AntonyC

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Just to back up the advice above, your pack measured 41.2V (in post #8) and cut out at 38V (post #10), a drop of around 0.32V per cell. The weak P-group started at 3.4V (post #8) and would have reached around 3.1V off-load when it cut out, so the BMS did its job there. Let the battery settle for 4 mins before taking readings.

0.8V imbalance is a lot when a cell's full range is 1.1V from full to empty.
 

Az.

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For me on/off switch is essential. One of my e-bikes has battery without switch. Removing and putting battery back was driving me crazy due to this spark, so I decided to leave battery on bike once. It was last time when I saw this e-bike working.

I see absolutely no reason why you would want to buy a battery without switch.

Yose kits and batteries are very good option for beginners, but as esteemed pedelecer you might like to look for another option for your next conversion. Starting with 48V system and battery with branded cells.
 
Last edited:

Woosh

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For me on/off switch is essential. One of my e-bikes has battery without switch. Removing and putting battery back was driving me crazy due to this spark, so I decided to leave battery on bike once. It was last time when I saw this e-bike working.

I see absolutely no reason why you would want to buy a battery without switch.
The mechanical switch drives a FET based electronic switch. It's the latter stage that is fragile and can be broken by the inrush current. When that happens, you have to replace the bms.
 

Woosh

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My recommendation is don't mess with your battery.
 
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guerney

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It is so much easier to buy battery with a switch.
Loads of forum dudes without time machines already have switchless Yosepower batteries. Judging by the look of flying saucers, time machine construction isn't easy, but I reckon even I can throw a waterproof MOSFET switch together, and I'm fairly new to soldering.

https://uk.farnell.com/infineon/irlb3034pbf/mosfet-n-ch-40v-195a-to220/dp/1698299

They could add a fun new dimension to range anxiety by using their Android phone to provide power to the MOSFET, effectively making it a dumb key.

 

saneagle

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Loads of forum dudes without time machines already have switchless Yosepower batteries. Judging by the look of flying saucers, time machine construction isn't easy, but I reckon even I can throw a waterproof MOSFET switch together, and I'm fairly new to soldering.

https://uk.farnell.com/infineon/irlb3034pbf/mosfet-n-ch-40v-195a-to220/dp/1698299

They could add a fun new dimension to range anxiety by using their Android phone to provide power to the MOSFET, effectively making it a dumb key.

When I first started with ebikes around 15 years ago, battery switches were not so common, so I made my own to fit between the controller and battery. I did it like post#3 here, and they always worked trouble free. If you read the rest of the thread, it's mainly intellectual masturbation and many alternatives suggested, but not many of them actually tried, and anything more complicated than what I did would require pcb manufacture. You can just about make mine without a pcb.


With all that said, all you're doing is duplicating what's in the BMS, so it's unnecessary. The MOSFETS in the BMS switch on when they receive 12v to 14v on the gate leg. That it is switched by a normal small transistor under instruction or logic from the BMS. Follow the track that runs from the gate leg of any of the output MOSFETs to find the transistor. You need to cut that track and install the switch across the cut. You can solder the wires for the switch to any of the pads where the MOSFET gates are soldered, and the other to where the track that you cut reaches the controlling transistor.
 
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