Oset 16 LiPo Battery

[Teddy]

I've been researching various lithium (LiPo4) battery solutions for the Oset 16. A cheap alternative I found has been this Eco-Worthy brand which are 12v 10Ah. They are the same size as the stock batteries so I will wire in series to get 36v 10Ah.

- On the Eco-Worthy datasheet, what values should I be looking at to ensure the Oset can draw the power required from the batteries? Looking at a total of $189 plus a charger.

- Can I use the standard Oset charger designed for lead acid on the Eco-Worthy lithium as it has a BMS installed? 

This is the data sheet on the Century PS 12100 lead acid battery I'm also considering which is very similar to the stock battery. Looking at a total of $135

The Milwaukee battery packs for 2 x 18v 8Ah is $400 plus the cost of the adaptors.

Thoughts? What option did you go with?

I'm located in Australia so I have seen some better options available in the UK and US on this forum.

Thanks

[Glayne]

We used upstart lead acid batteries off of Amazon, batteries worked well enough and good price. To be honest by the time you put much time and money into those Osets your kid is grown out of them. Had 3 little electrics for a few years, feels like a few months now. My youngest just turned 7 and is on his 5th bike and looking for a Beta 80 to be his 6th!  And from what I've heard in the RC world the LIPOs can be dangerous?

Edited June 22, 2021 by Glayne
add info

[Teddy]

Thanks but we are just talking about $135 (Century Lead Acid) vs $189 (Eco-Worthy Lithium) so the boys can get at least another hour out of the bike. The concern at this stage is more around the $189 lithium battery. For example if it has the power and is built to a high enough quality for the bike.

[Teddy]

I've come to the conclusion the Eco-Worthy battery won't be fit for purpose. If the 800w motor is 36v that means a peak discharge of 22.2A would be needed. The Eco-Friendly battery is rated at 10A discharge.

I'm now investigating batterys on AliExpress. 

This battery AERDU 36V 11.6Ah 10S4P 18650 Lithium battery pack for 36V batter 250W-750w ebike electric car bicycle motor scooter with 25A BMS looks like it maybe fit for purpose at 

[Westcoast]

Depending on how your kid rides, 10Ah wont help much.  I'm sure you've discovered the standard SLA's at 10AH have horrible voltage drop during the 1st hour of use (even after 30 mins).  You won't get double performance going with LiPO in the same amperage.  I now have 16 5S LIPO packs wired into 2 8-pack bricks giving 42V 20A at full charge.  We run 1 8-pack brick at a time.   This solution is neither cost effective nor easy to manage but it does work.  You need to actively monitor voltage during use (a meter on the bike) and know when to stop as RC LIPO's won't shut off for you.  They'll just begin to destroy themselves.  Also, I believe the 16 under load could pull up to 30A or so.  Sure, watts/volts=amps says we should be around 21A with 12.8v SLA at full charge, but the ammeter on the bike suggests we can pull more than 25A.  This isn't a problem with ordinary standard RC 25C LIPO packs designed for high discharge but definitely a problem with many pre-built packs with low amp BMS's.  They'll fail. The pack you've found says the BMS can handle 25A but I don't see a peak value.  If you were running only 1, I suspect it would blow the BMS, but 2 packs in para probably works.  Oh, just noticed they are 185mm long which might be slightly too long for the tray on the 16 too. 

Savvy parents in the US have found these packs and use 2 in parallel (10Ah version): 

https://www.amazon.com/Electric-Battery-Lithium-LiFePO4-2000W-250W/dp/B096RRCD4F

I'd go this route if I was doing it again from scratch.  Order a pair and save a lot of management and charging hassle.  And they are good battery chemistry being LiFePO4.  Unfortunately the seller refuses to ship to Canada,  I've asked.