Using other batteries on Panasonic lithium powered units

[flecc]

I've posted some of this information in another thread, but am posting it here in full with photos for future reference.

This is to explain the 5 pin connections on this battery system:



As you can see from the case outline, pin 1 is nearest to the rear of the bike, pin 5 to the front.

Pins 1, 2 and 4 are used in charging:

Pin 1 is a charging monitor, presumably of temperature.

Pin 2 is the common negative connection.

Pin 4 is the charging positive connection.

Pins 2, 3 and 5 are employed when the the battery is mounted on the bike for use:

Pin 2 is the common negative.

Pin 3 is the battery charge state meter signal going to the handlebar meter.

Pin 5 is the output positive.

Therefore, when using another make of battery, connections for the two leads to the underside of the bike's battery platform are:



Positive connection to the platform pin position 5 nearest the front of the bike.

Negative connection to the platform pin position 2 nearest the rear of the bike.

The pin position 3 in between is redundant then.
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[andyh2]

That's jolly useful, thanks Flecc

 

[tillson]

Thank you very much for putting this reference information together. This is certainly an option that I will be considering. Now to do some research on suitable batteries.

 

[Deleted member 4366]

That's good stuff. Well done all those that contributed. Now we have a new question: What happens if we connect a 36v battery?

 

[flecc]

Now we have a new question: What happens if we connect a 36v battery?

I'd guess it's quite likely it wouldn't get past the self test pre-startup stage. Also the motor on these is plastic cased, additionally cowled and can already get very hot at times, so a 50% voltage increase could bring problems even if it did work. Although the motor failure rate has been very low, a few have failed. There would be no speed increase due to the higher voltage since the speed is controlled and limited by the Hall sensor feedback rate.

In respect of the 36 volt Panasonic systems for 2012, they may not have the same connection arrangements I've reported above, since they may have prevented battery interchange for technical reasons.
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[andyh2]

So does this mean that a Ping 24v LiFePO4 battery with +ve and -ve leads attached the right way round to pins 2 and 5 on the bike could be used to power my pro-connect.

Is it that simple or is there anything else to consider?

 

[flecc]

Yes, it's that simple. You wouldn't have handlebar battery metering but otherwise it would work fine.

 

[lemmy]

The problem would be where to mount the thing. Otherwise the 15ah model at under £200 would look a good buy.

 

[tillson]

I have not carried out any investigation to see if this is feasible, but my initial thoughts are to gut the existing Panasonic battery when it is no longer of any use and to route the feed to the motor via the case and existing battery connector (a wire entering an empty case and connected to the 5 pin docking unit). I would then put the new non standard battery in a pannier. This would involve no modification to the bike or motor, and facilitate the use of standard batteries at some point in the future if needed.

 

[andyh2]

I calculated a Ping 10Ah shipped with VAT and say a tenner for handling would be £270 (compared to £375 for panasonic)

and the 15Ah on same basis would be £330 compared to £525 for panasonic 18Ah.

Whilst Ping has a very good reputation it's a compromise trading warranty and ease of return against price.

I'd certainly prefer to buy in the UK. Have look into the options (and probably end up with a panasonic

 

[flecc]

Immediately after my posting this thread, I had an email though my Panasonic support site from a Japanese user saying his 2009 Pro Connect Panasonic unit won't work with another battery and the meter connection not in use. I mailed back immediately asking for more details but have had no reply as yet.

I also PM'd member Orraman (Dave) for more confirmation on his usage of another battery. He has two Panasonic unit bikes, a Gitane with the 8 Ah battery and a Technium with the 10 Ah battery and confirms the batteries are interchangeable. In addition, he has used his Cyclone LiFePO4 battery on the Gitane without the meter connection in use and without problems. He says that at switch-on the three LEDs light up for a few seconds then reduce to only one LED which continues until reaching the Panasonic battery low level when it blinks as normal, so the meter still works with that other battery.

However, the Cyclone battery he says is a lower voltage, nominally 24 volts it's probably has seven 3.3 volt cells totalling a nominal 23.1 volts, though higher after charging of course. The official batteries for the Panasonic units are based on a 7 x 3.7 volt Lipo cell structure so are nominally 25.9 volts.

Therefore it's just possible that his only works ok because of that lower voltage, though that seems unlikely. However, it's also possible that the Japanese user hasn't connected up correctly.

Obviously I'd like to hear of a nominally 26 volt lipo used with no meter connection before saying finally that all other batteries are ok on these Panasonic units.

 

[lemmy]

and the 15Ah on same basis would be £330 compared to £525 for panasonic 18Ah.

Given the neatness of the case and fitting plus battery management plus re-sale value if sold with the bike, that makes the Panasonic unit look a better buy to me.

 

[tillson]

Given the neatness of the case and fitting plus battery management plus re-sale value if sold with the bike, that makes the Panasonic unit look a better buy to me.

I agree it's a very close decision especially since my Panasonic battery seems to be lasting so well. This needs some more thought.

 

[flecc]

I've now heard back from Shinji Maeshiro, the Japanese user who finds his 2009 Pro Connect won't work with another battery and the third connection out of use. This is what he reports:

On connection only one handlebar meter LED lights, the bike starts but within a few seconds it starts flashing and the bike shuts down as if at end of charge. This compares with our member Orraman (Dave) who gets three LEDs lit for a few moments, then immediately down to one only lit for the duration of use until the battery is low, when it starts flashing as normal.

Both batteries are nominally 24 volts but there are important differences. Shinji's which doesn't work is an NiMh which with full charge measures 28 volts. Dave's which works is an LiFePO4. I don't at present know from him it's full charge voltage, but he says it's lower than the Panasonic one so is probably a 7 cell pack. That would indicate it's full charge voltage is 25.2 volts, but if it's an 8 cell pack, the full charge voltage will be 28.8 volts. The normal Panasonic battery full charge voltage will be 29.4 volts.

Therefore, it doesn't seem likely that the voltage differences are causing the difference in behaviour, so I can only think of the difference in cell resistances of the NiMh possibly causing the problem on Shinji's bike. While it's possible Panasonic have introduced a blocking to prevent use of other batteries without a third connection, it seems unlikely when both these mark 2 units are those using the current battery type and not the earlier mark 2 one which had some battery differences.

Obviously we need further experiences before we can be confident about using any two connection lithium batteries universally on these units.
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[Orraman]

Tillson,
From the previous thread, sorry But ~~
I have been without an internet connection for a few days and failed to respond to my names.
Note, Travelscoot is my Cyclone battery powered lightweight mobility scooter that I nip round the shops on and transport on my ebike trailer.

Eventually I received a PM from flecc requesting more information, particularly if the Cyclone battery had been used on the Technium which it had not.

I have had no reason to use the Cyclone battery on the Technium and as mentioned the Cyclone connectors are somewhat strained open when pushed onto the Panasonic blade terminals. This was acceptable when the battery was being used only on the Panasonic but I closed them up to fit the Headline (200W Cyclone motor) blades on the Travelscoot. I will try to make adaptors rather than fatigue the brass fittings and will let you know the results.

I have an 8Ah and a 10Ah Panasonic and a 10 Ah 8 cell LiFePo4 Cyclone battery and have used them interchangeably on a Panasonic Gitane Ebike 8.

Both 10Ahs are charging in the kitchen to get a fresh off charge voltage. Done.
10Ah Panasonic 29V.
10Ah Cyclone 28.4

After 15 minutes
Panasonic 28.8V
Cyclone 27.2V

After 30 minutes
Panasonic 28.8V
Cyclone 27.1V
Will see if I can knock up agricultural adaptors tomorrow.

Volts this morning.
Pan 28.7
Cyc 26.7

But it works.
Cyclone battery on Technium.
Lights as before, quickly settled to 1 light which remained steady climbing a nearby hill in middle and full power.
Very cold here, the Master was happy to offer me her tripod and remote when I suggested she might provide photographic evidence on said hill.
Dave



The right hand kit shows the components in my Cyclone battery.
Cells & Accessories

 

[flecc]

Many thanks for your help on getting these confirmations Dave. The voltages are exactly what I would have expected for the two battery types, 7 series cell based in the Panasonic Li-polymer and 8 cells in the Cyclone LiFePO4. The fact that both the 10 Ah equipped Technium unit and the 8 Ah equipped Gitane unit work ok on the widely differing voktages and types suggests that any nominal 24/26 volt lithium battery should be ok for use with the second series of Panasonic 26 volt units, but losing any indication of declining battery content until near cutoff.

My Japanese contact, Shinji Maeshiro, has failed to get his working with a nominal 24 volt 5 Ah NiMh battery. His fully charged voltage he reports as 28 volts, well within the span that Dave is successfully using. I can only think that the different characteristics of NiMh are the problem, most probably the difference in cell resistance upsetting the Panasonic control circuitry, provoking the system end-of-charge shut off after the initial self test phase.

 

[tillson]

Thank you posting your findings Orraman. They, together with flecc's thoughts posted above seem to point to the fact that our Japaneese friend was using a NiMh battery pack, and this is the reason for his lack of success with the alternative battery.

As andyh2 has already pointed out, the economics of buying and using an alternative battery as opposed to an original, are close. However, I still find the idea idea strangely appealing!

 

[flecc]

As andyh2 has already pointed out, the economics of buying and using an alternative battery as opposed to an original, are close. However, I still find the idea strangely appealing!

It's the rebel in you!

 

[Orraman]

Seeking further gen I've just taken the Technium to the top of town with the Cyclone battery and have the slightest feeling that it is not pulling as well as the Gitane but the Gitane being only 3 speed is likely to have a lower top gear.
On the other hand this battery is 3 1/2 years old and has had a fair old howking, first on a hungry Currie motor, then the Cyclone on the recumbent where it received no mercy, too much fun. Charging at a steady, metered 5A always.

On toy planes I discharged NiMh 3000mAh at 30A for sport and other folk at 90+A for competition gliders so I wonder if our friend with the 28V NiMh has done a 15A discharge while testing the voltage.

Dave

 

[tillson]

It's the rebel in you!

I like to live life on the edge. I have been known to run whilst holding a pair of scissors, pull faces in changeable wind conditions and approach swans, knowing that they can break a man's leg with their wings. This battery stuff is tame by comparison.