PANASONIC ebike battery change

Are there any examples of anyone successfully bypassing the BMS for the Panasonic drive system?

I must admit I'm tempted to pick up a used bike with a Panasonic drive system on it and building my own battery.


Now I have a ton of 4S li-ion packs, so if I could use 8S (~30v) or even 12S (~42v) with this system then I'll be set.

Would 44v be too much if the system is designed for a 36v battery or will it be a case of trying it with a temp sensor on the motor and seeing how hot it gets?

Thanks :)
 
After replacing the original with 2 LiPo batteries from Zippy, 7S*5800 mAh, I was not able to keep the original BMS....it simply didn't recognize the new batteries :(
Not a big issue, having already installed the Cycle Analyst I know:
- the mAh consumption
- and when to switch the battery off (min = 25 Volts to be safe) :lol:
I also have to use a new charger (iCharger 208B), but this is at least 4 time quicker than the original one 8)
Those 2 Zippy perfectly fit into original Panasonic battery case, I only had to put some foam to avoid movements while on the road.
If you want to see how those 2 Zippys fit into the original Panasonic case: http://youtu.be/IbTzMxvp97k

In the future I am planning to test an 8S instead of a 7S, so your experience with 2X4S looks very interesting also for me!
 
why does that link say youtu.be instead of youtube?

if your battery allows one cell to drop under 2.7V then what is there to stop it from over discharging and what happens if you short it?
 
I don't know, I just did a cut&paste from youtube....were you able to see the clip ?

When I charge the battery I always select BALANCE/CHARGE.
It looks like the average unbalance amongst cells is around 0.01/0.02 volts: so when the pack goes down to 25V, each cell should be around 3.57 plus-minus possible unbalance.
Here you can see what I mean: http://www.youtube.com/watch?v=m3cuFoxzYVU

I don't think that 1 cell could drop suddenly to 2.7, otherwise balancing cells wouldn't really help a lot!
 
i have great fear of logging on to domains in belarus.

i know the balancing charger will balance the cells, i just wondered how you will know if one cells goes bad and drains faster than the others down below 2.7V?

everyone seems to assume that these cells never short out internally either so they think they can bulk charge them in between balance charging and all is safe.

but there is a lotta evidence that sometimes these lipo cells will just drop to 0V and some even come from hobby king with 0V already.

i have seen 6S packs with two cells at 0V and one at 4.5V. the other 3 were still working. just deformed by the puffers.
 
it's good you noticed that....
actually I have posted this video on youtube, so when I got the (strange) URL back after the end of the upload I haven't noticed that :(

I guess when you say:
"i have seen 6S packs with two cells at 0V and one at 4.5V. the other 3 were still working. just deformed by the puffers."
you refer to battery packs that have not been balanced/charged recently.

May be I am wrong :oops:, but if I keep doing systematically 'balance-charge' my LiPO's, the chances that while using them one cell suddenly drops under 2.7 V is extremely low.
I have been doing this for the last 3 or 4 months, and each time I didn't notice more than 0.06/0.07 Volts difference amongst cells.
I will keep an eye on how this gap goes on, whether it increases or may be decreases thanks to the balancing exercise.
 
osa57 said:
it's good you noticed that....
actually I have posted this video on youtube, so when I got the (strange) URL back after the end of the upload I haven't noticed that :(

I guess when you say:
"i have seen 6S packs with two cells at 0V and one at 4.5V. the other 3 were still working. just deformed by the puffers."
you refer to battery packs that have not been balanced/charged recently.

May be I am wrong :oops:, but if I keep doing systematically 'balance-charge' my LiPO's, the chances that while using them one cell suddenly drops under 2.7 V is extremely low.
I have been doing this for the last 3 or 4 months, and each time I didn't notice more than 0.06/0.07 Volts difference amongst cells.
I will keep an eye on how this gap goes on, whether it increases or may be decreases thanks to the balancing exercise.
Click to expand...

True, but the consequences are extremely BAD....

That said, I don't use auto BMS but I do voltage check every cell before each charge. I also constantly measure cell IR and log cell voltages under riding conditions. Any significant change in sag and/or capacity is a cue for visual inspection and further qualification testing.
 
My Panasonic BMS recognizes the 2x7S Zippy batteries just fine, so you must have connected the balance wires wrong.

Beware that the Zippy's balance plugs have reduntant wires, as both the 4S and the 3S plug is complete, so the last wire on the 4S has the same potential as the first 3S wire.

I haven't had much time to ride the bike, but so far it looks promising.

I rode until the last LED on the handlebar was flashing, then I went on three weeks holiday and put the battery on the original Panasonic charger, and thought "Oh-No" as the last LED started flashing for maybe a half hour, but then it turned solid, and during the next 6 to 8 hours, more and more LED's turned on and finally they all turned off, indicating full charge.

It doesn't pull as hard as I remember the bike doing when new, but I have a suspicion that the grease inside the motor has turned stiff, and the drive sprocket is worn and the tensioner also looks suspicious.

I will try to get a larger drive sprocket to increase the cadence from Japanese granny level.

Now my other problem is that Hobby King's European warehouse are out of all the larger 25C 7S Zippy Compacts, so I cant recell the Yamaha Pedelec that i bought as stablemate for the Kalkhoff.
 
I didn't connect the new 7S Zippy with the old Panasonic balance plugs...this is why the BMS doesn't recognize them 8)
Too much work and what about the old Panasonic battery then ?
I still use it as a back up...

So I am not too worried about the fact that I cannot charge the new Zippy with the old charger: moreover I am going to buy a charge board to be able to perform parallel charge for both in one hour max (at 1C).

For your information I have changed both standard Zippy 7S 4S and 3S plugs with one 8s plug: I still don't understand why should the Customer do it instead of Zippy factory :evil:

I think that a recharge time from 6 to 8 hours is a lot, hopefully for you it is going to improve!
In my case I have a 12 teeth drive sprocket: for my pedaling style (high cadence) it's a good set-up, the motor keeps pulling until 95 rpm.

Good luck with European supply for 7S!
 
Tell me about the European supply for 7S Zippy cells!

I got stiffed by Hobbyking, and finally got the order canceled and a refund.

I check the site dayly, and when 5000mAh 7S came in stock the other day, I ordered two for the Yamaha.

A 12-tooth sprocket is also in my plans.

I agree about the balance plugs.

My Panasonic cells have 5 to 6 times the internal resistance of the Zippys

I have made adapters for the balance plugs, so the Panasonic cells can be balance charged on the Junsi, and re-installed in the battery case, and the zippys can connect to the Panasonic BMS.
 
Hi,
I finally received the 8S Zippy LiPo battery from HobbyKing :D
1) I first tried to use on the Panasonic with the Voltage it was shipped: 30.7
No problems, the Panasonic engine was running fine, punchy, and with almost no Voltage sag :mrgreen:
2)Then I charged the LiPo at 32 V: even in this case no problems at all, the engine was running at its best :)
3) Now I still have to charge the 8S to the max (33.7) and see what happens: I have reasons to believe that not having any longer the original BMS, this should not be an issue for the engine.
As usual I am fed up with HK standard balance plugs, in this case 2 with 5 leads each :evil:
So I need to replace them with one: easy to do but I have to order the good plug now!

In summary:
- pretty good 'punch'',
- I am glad to go from 300 Wh capacity (with 2*7s) up to 340 (with 2*8s)
 
The saying goes: "If it doesn't kill you, it will make you stronger.
I'll modify it to: At least the motor will pull stronger before it dies from overloading
 
Hi,
great news , i also have a flyer c5 2009 with an old battery, i thought to buy a new one, but didn't know that i just could connect a random battery without the original bms and start the motor :D.
How is the motor assistance with 8s???With my original battery it's not that great, while pedaling steep hills.
 
The Zippy cells didn't survive the winter break. Their capacity was very poor, despite all 5 led's turning on when the test button was kept pressed.

Opening up the battery case revealed that all cells had puffed up, some of them had actually burst.

I got 1½ years service and maybe 1000-1500 km's out of them.

I took a set of 5800mAh Zippy LiPo's from my Yamaha and installed it.

They were at 4V per cell, and when I started out, 1 led was blinking on the battery case.

After a short spin, the led had gone out, and 1 lit up when pressing the test button.

I put the battery in the charger, which went through the usual process of more and more led's being lit, until all 5 were lit and finally went out.

Next phase is the "down to cut-out" calibration run.
 
This set had been performing poorly during the summer, and sure enough, all 14 bags were puffed.

I think I'm better off ditching the Panasonic BMS and using a proper external balancing charger.
 
After 3 years and almost 10000 km, both my 5800 mAh Zippy batteries are still in excellent shape :D
Every time I recharge them, they are (almost) perfectly balanced.
I normally charge them in parallel, so the complete recharge ( having set the Lipo charger at 10Ah) takes one hour at most.
I never let the single cell voltage drop below 3.5 Volts (thanks to the Cycle analyst).
 
Yes, I am using 2 LIPO's 8S (5800 mAh each) on a Panasonic 26V ebike.
Please note that since I am NOT using the original BMS I have installed a Cycle Analyst to monitor the battery discharge.

You can also check some more details here: [youtube]5Y5ycw5jNUU[/youtube]
 
I've had similar experience with the Yamaha, even leaving the two pack connected in parallel on the balance wires for months.

I've come to the conclusion that any e-bike that requires a specific BMS to run (like the BionX and never Bosch system) will most likely be worthless after a couple of years due to exorbitant battery replacement costs.
 
Hello Daniele

osa57 said:
After 3 years and almost 10000 km, both my 5800 mAh Zippy batteries are still in excellent shape :D
Every time I recharge them, they are (almost) perfectly balanced.
I normally charge them in parallel, so the complete recharge ( having set the Lipo charger at 10Ah) takes one hour at most.
I never let the single cell voltage drop below 3.5 Volts (thanks to the Cycle analyst).
Click to expand...

I am trying to do the same as you, I would like to replace the battery for my wife's used Flyer (26V)
Because you had success in bypassing the BMS I would like to ask if you needed to connect the battery state pin to the battery case.
My plan is to buy a ENERpower Softpack 24V 7S3P 10.35Ah with BMS Pedelec Battery (7×3) DIY 3XLR
so I would need to buy a charger and connect the terminals from the discharge cable of the battery directly to the pins of the battery case. Is this correct or am I miss understanding something?
Im trying to figure out this with the info in the forums but Im getting a bit confused. Someone wrote that the panasonic motor controler will enter some kind of "emergency" mode if the battery state pin is not present . Our flyer is an old one with no battery indicator, but it starts to blink when the battery is empty.
So if you bypassed the panasonic BMS , how did you solve this?
Thank you so much for any pointers.
Luis
 
This battery is easy to rebuild with 18650 cells.

I use samsung 3400mah cells: 7S-5P and stil can use the original bms & charger :bolt:
Ful charge and discharge wil reset the led indication on the battery to 10Ah...
6,75Ah is spare energie and you can cycle this energie out of the battery no problems :lowbatt:
16,7Ah- 420Wh 70km in boost 90km in normal and 110km in eco :bigthumb:
 
redcap said:
Hello Daniele

osa57 said:
After 3 years and almost 10000 km, both my 5800 mAh Zippy batteries are still in excellent shape :D
Every time I recharge them, they are (almost) perfectly balanced.
I normally charge them in parallel, so the complete recharge ( having set the Lipo charger at 10Ah) takes one hour at most.
I never let the single cell voltage drop below 3.5 Volts (thanks to the Cycle analyst).
Click to expand...

I am trying to do the same as you, I would like to replace the battery for my wife's used Flyer (26V)
Because you had success in bypassing the BMS I would like to ask if you needed to connect the battery state pin to the battery case.,.............
Thank you so much for any pointers.
Luis
Click to expand...
Hi,
I didn't connect the 'battery state pins' to the battery case.
It was too difficult for me with my tools 😙
Of course now I don't see the LEDs on the battery case about it's charge status.
But from my Cycle Analyst I get very reliable information.
And when I charge the battery, the different elements are well balanced, max 0,1V difference
Regards
 
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