coolio

I'm having an issue with a bionx battery pack that has been unused for a while. I bought it used, so there is no warranty on it. I found a page in the nycewheels site that recommends that you suspend the bike and pedal it until it recharges it enough to get a current. I tried it for 20 mins and it didn't work.

I want to manually charge it with this SLA charger/maintainer to see if I can bring it back:

https://www.amazon.com/BatteryMINDer-.../dp/B000P23HZS

Would this work?

CigTech

The answer is yes, no, and mabye if you have a LIpo Battery. But the If Bionx battery is a nickel metal hydride then NO.

First of all, we'd need more information on what's in the battery box. They have a 24v nickel metal hydride or a 36V Lithium Ion battery pack.. If you hvae the LIPO4 then only if it has a BMS in i. It you have a Lithium Ion battery then NO because most Lithium Ion battery do not have a BMS in the pack. If you have the nickel metal hydride then NO because of no BMS as well. Some have charged bms equipped lifepo4 with a BMS with sla chargers for months with no damage

Bottom line, if your SLA charger undercharges your pack, you are likely to be ok with it. If it overcharges it, it might ruin it.

The main difference with a lithium charger is that when done, it shuts completely off. Later, when the bms (if present) works to drain down high cells, it might be capable of turning back on again, and bringing up the lower charged cells.

An SLA charger will go into a float charge mode. It never shuts completely off. It will provide a very small trickle of power at a constant voltage, designed to keep a lead battery topped up. Lithium batteries don't need the top up, and might be damaged by overcharging. In the case of the SLA charger I was using, it finished about 2v undercharged, so there was little chance of it overcharging my lifepo4. If it began to, the bms would start slowly draining any overcharged cells.

powell

when LITHIUM BIONX battery voltage drops below 10V BIONX charger no longer can recognize it and will not start charging.
YOU have to open battery and rise voltage manually SLOWELY but steady to at least 30V /again I talk about LithiumBIONX/
The way to do it is to connect wall adaptor with DC output at least 40V and 0.5 Amps directly where battery connects to BMS, simply to charge outside BMS. It must be DC output adaptor /check label on it/ not AC output.
You must monitor voltage every couple of hours not to overcharge.
Again you want to do it slowely so no more than 500mA /0.5A/
instead of wall adaptor you can use lab power supply with current udjusted at no more than 500mA.

Bionx battery is 36V so I imagine 12V charger would have to be used to charge 3 section of battery seperate.

coolio

Thanks for the responses. Yes, it is a 36v LiMn system. And, the bionx pack is the battery pack with the BMS built in to the unit. So, you have the battery pack and there is a circuit board within this little case where all the components are.

I asked about the charger that I listed up there because it is one I already own. Powell, would I have to buy another special charger? Funds are kind of tight and wanted to do this with some chargers that I already have. Here's the page I referred to about boosting your pack by pedalling:

https://www.nycewheels.com/bionx-diag...-recovery.html

the battery pack is shrinkwrapped with some kind of plastic. I guess I have to take it all apart?

ambroseliao

Just make a single slit down one side. That way you can rewrap the battery with the same shrinkwrap and tape it back together much more easily with some clear wide tape.

leterroir

hi, I'm trying desperately attempting to revive a dead 36 volt Bionx battery; and like the approach. Given the high cost of a replacement battery - I thought the following purchase would do the trick: https://www.amazon.com/gp/product/B00...=ATVPDKIKX0DER

The only question I have is where to connect the leads in order to effectively bypass the BMS. Not that access is easy - but man, would a photo of which leads to connect to would be hand; or perhaps a good description with colors, et al.

Thanks a million.

powell

very nice unit
I also cannot provide photo.
you must find beginning of string of cells , where is plus and where is minus.

harrijohnson

I am having not dissimilar problems with 48v BionX battery pack.
The charger will not see it and I have tried the pedalling bike thing to no avail.
Have now dismantled case and put voltmeter across the wires that come from battery pack and they are showing 30v (max of my primitive meter).
can I put the 48v charger across these large red and black wires directly? It has a charge output of 2amp.
thanks

powell

definitely,
I would connect 48V charger directly where cells are connected to electronics and watch voltage increase until say 40V.
And ext try to charge normally through charging port.
I hope it helps