Oset Batteries Lithium (LiPo) Conversion Directions

[gwhy]

Something else you can do with 20Ah of hobbyking batteries

Its vids like this that will make people sit up and realize that for real power Electric is the only way to go. The chap In the vid that made that bike is a power freak and always pushing the limit , The bikes Im playing with has as much power but do not have as much top end, the bike in the vid does around 60mph and my bikes are only geared for 30mph, the power delivery from a very powerful electric bike is a whole new ball game and great fun.

[kaelem]

Will be getting my lipo's today, my mate shaved 6.6kgs off the 36v! Thanks for all the info.

[cort]

I have looked at Hobby King and cannot find any 8S or 10S batteries for less than $111. Am I missing something here?

[mikedufty]

6S is the size you want for 24V Are you wanting it for a 36v?

zippy are the cheap ones.

Seems to be a 10s for $82 but it looks a bit long, might be hard to fit. Probably do better with a 6s and 3S in series.

http://www.hobbyking.com/hobbyking/store/uh_listCategoriesAndProducts.asp?idCategory=235&LiPoConfig=10

[cort]

Thanks for that info. Yes, it's the 36V. So, would I hook up two pair of 6S/3S in series, then connect those together in parallel?!

[cort]

One more thing: What charger will I need for 10S batteries? Thanks!

[gwhy]

One more thing: What charger will I need for 10S batteries? Thanks!

You will need a CCV charger for lipo's , I not sure if HK do a upto 12s charger ( if they do it will be very expensive ) you may be better off using 2 18v (5S)or using 4S and a 6S( you can just have 1 charger but it will take twice as long to charge the pack )remember that a 10s lipo will give you around 40v'ish hot off the charger ), buy 2 6S chargers from HK I think they are around

[cort]

Thanks. Would I need four 6S chargers for two 10S batteries, then?

[gwhy]

Thanks. Would I need four 6S chargers for two 10S batteries, then?

I just had a look on HK website

looks like the only 10s bat charger that they do is this one charger you can charge both packs from one charger but will take longer to charge so 2 chargers would be better but that will work out very expensive ( the chargers are expensive ) in addition to the chargers you will also need a 15A mains power supply (to power the chargers ) and that in itself will be expensive. With the cheaper 6s chargers you can charge all cell counts of battery upto 6s cheaper charger

this charger will not charge as fast as the 10s one but even if you bought 4 cheaper chargers it still works out cheaper than the expensive one, the mains psu's for the smaller chargers are also cheaper than 1 big one so 4 cheap chargers and 4 5A mains psu's will come to about the same price as just 1 of the exspensive 10s chargers without even buying the mains psu for it. I hope this makes sense, it can be all a bit of a mine field at first. To answer your original question you can charge as many 10s packs all at the same time with one 10s charger at the cost of it takes longer to charge.

[cort]

I just had a look on HK website

looks like the only 10s bat charger that they do is this one charger you can charge both packs from one charger but will take longer to charge so 2 chargers would be better but that will work out very expensive ( the chargers are expensive ) in addition to the chargers you will also need a 15A mains power supply (to power the chargers ) and that in itself will be expensive. With the cheaper 6s chargers you can charge all cell counts of battery upto 6s cheaper charger

this charger will not charge as fast as the 10s one but even if you bought 4 cheaper chargers it still works out cheaper than the expensive one, the mains psu's for the smaller chargers are also cheaper than 1 big one so 4 cheap chargers and 4 5A mains psu's will come to about the same price as just 1 of the exspensive 10s chargers without even buying the mains psu for it. I hope this makes sense, it can be all a bit of a mine field at first. To answer your original question you can charge as many 10s packs all at the same time with one 10s charger at the cost of it takes longer to charge.

[cort]

Thanks so much for your thoughts on this. You clearly have spent some time considering and researching your answers, and I appreciate that.

Is there any reason that I could not use my car battery to recharge the batteries and save the cost of the power supply units?

Also, a friend offered to let me use the batteries from his son's 24V bike as a backup set this coming weekend. Do you see any problems with running them in my son's 36V bike?

Edited September 20, 2011 by cort

[mikedufty]

I suspect charging a 36v from a car battery will run the risk of flattening or damaging the car battery.

I did initially charge my 24V setup from an old car battery, with a cheap car battery charger connected to it to stop it going flat. It worked, but I'm not sure if it was a good idea (the car battery charger is too high an output for my charger, but I figured the battery in the system would level it out). I'm much happier with my current setup, which is much neater and also free, I just found an old laptop power supply brick with the right output voltage and current. I imagine there are plenty of suitable ones being thrown away regularly everywhere, not quite sure how to get your hands on them though if you don't have your own lying around.

Edited September 20, 2011 by mikedufty

[gwhy]

Thanks so much for your thoughts on this. You clearly have spent some time considering and researching your answers, and I appreciate that.

Is there any reason that I could not use my car battery to recharge the batteries and save the cost of the power supply units?

Also, a friend offered to let me use the batteries from his son's 24V bike as a backup set this coming weekend. Do you see any problems with running them in my son's 36V bike?

Yes you can charge the battery from a car battery but as Mike have said it will drain the car battery in no time and possible damage it. The PSU's can be bought cheap, you will need for each charger a psu capable of 12-18V at about 5A these can be found new on ebay for around

[cort]

Thank you, thank you, thank you to each of you.

[ninefives]

First - thanks to all who have contributed so far on this thread, so much information, actually that is my problem - I'm confused by all the variations and am really looking for help to define a sensible repeatable setup (for 36V Osets) that folks like me can easily understand, shop and put together. I'm more mechanical than electrical so please be tolerant of any stupid assumptions I make.

We have a 2010 36V Oset and the main issue I want to overcome is range, I really need about double the life I currently get from the SLA's with probably 30 charges on them (properly charged initially and seem to be holding close to original range). I can then have my son come with me on the trial loop without concern for getting back.. I'm happy to convert to Lipos. From what I have read:

Batteries: To convert to LiPo and to give the existing range - 6 x 3S1P15C 5000ma (3 batts in series giving 33V) and the 2 banks in parallel giving me 10ah. I could replace 2 x 3S with a one 6S (this reduces the connectors but (I think) may complicate charging (more later). To increase the range I could add further banks of 3x3S1P 5000ma. Each 5ah layer would be 150x143x23 mm and cost about US$75 from HobbyKing, the weight saving is huge - standard OSET batts setup is 10ah weight 9.1kg, LiPo is 2.7kg per 10ah.

Question - Is there a heat issue with stacking the batts, as each layer of 3 batt in series would fit nicely in a hard sealed case in the OSET battery compartment and they would be 3 or even 4 layers deep (20ah!) and assuming a continuous but variable use.

Setup - Discharge (riding)

I would replace the batt connectors with XT60 and use the series connectors on each layer (33v and 5000ma) and parallel connectors to connect the layers to get to 10, 15 or 20AH capacity. I would then need to change the current bike power connector to XT60 and disappear into the sunset, but..... charging.

Setup - Charging

I don't want to have to remove or disconnect the batteries to charge them. I understand the fire issue but am prepared to buy a charger that manages voltage/current/shutoff - which I assume should reduce this risk considerably. So - I have 6, 9 or maybe 12 3S1P batteries all connected in a sealed box and ending in one XT60 connector carrying 33V. Each battery has a +ive -ive and a balance plug for use when charging. This leads me to believe the only way to charge these batteries will be with a separate charging circuit as I haven't seen a 33v charger and I haven't connected the balance plugs to anything yet.

Hobby King have a Parallel Charging board ($8.99) "Our very own in-house designed and built parallel charge board! Now you can charge SIX (2~6S) lipo packs with same capacity & cell count simultaneously with this parallel charging board. That means you can charge 6 3S 2200mAh or more at the same time with a standard charger!" (The same cell count was what made my decision about using all 3S rather than a mix of 3S and 6S).

Question - Can I branch the discharge circuit from each battery to create individual charging circuits that would terminate with XT60s (with it's associated balance plug) on the case cover, leads would then connect to the external parallel charging board and the charger? Or is there a simpler way to do this?

Question - Having got to the point where I have the ability to charge the batteries (my assumption), what charger would be recommended, assuming that it would need to charge 9 or 12 3S1P 15Cs through 2 parallel charging boards. I should add that I'm not planning on charging in the field but back home unless it is fairly simple and I don't have to rewire my minivan to make this happen in the field.

I hope that through all this, with your help I can maybe get to a diagram, shopping list and instructions on how to easily improve the performance of these excellent bikes. Thanks in anticipation !