Skatey 800/fiik big dady/ superstar - Lead acid to LiPo conversion

hi i have a skatey 800 i bougt it second hand but the lead accid batterys ar dead fist i wanted to put new in but i was like lipo is way better but then i have a problem becous if the lead battery are empty they are 36v total and when they are full they are 45v so that comes down to like a 10.8s battery so i wanted to get a 11s battery but that woud meen i need a 5s battery and those ar quid rare so my question is is it better to use a 12 s or a 10 s ???

Hard to tell. Depends on electronics and their limits. Might choose 10s for safety reasons.

wil that like 2v matter that much in speed ??

One of your options is something like this:

Buy 2x 6s Lipo’s.

Leave one of them alone, but the second one, open up the pack, de-solder the wire/s from one of the terminals, then remove that cell from the pack.

Solder wires to the ‘‘new’’ last cell in that pack, which would be 5s now.

The hardest part would be to figure out how to charge this thing and how exactly do you need to wire the balance wires together.

Do you have lipo charger right now? Im asking because even with 11s pack, it looks like you get 46.2v. To make it '‘totally standard’ I would charge that 11s pack of lipos till only 4.1v per cell, then you would get 45.1v, you could charge them in Li-ion setting or just make a ‘‘custom program for lipo’’ to terminate charge at 4.1v.

This is a very labor intensive task, You might as well try to find 2x 4S batteries and 1x 2S battery, all in the same capacity range. You would get a really weird wiring and you would still need some soldering to make custom 3 battery connector but at least you would not need to take apart the lipo cell.

There is a thead about making lipo packs slimmer. Take a look there. Then you can judge will that be hard for you or not.

This is from theory, as I have not soldered / re-assembled lipo packs myself! But it should work, if you can make all the right connections!

Im sorry that I can not give you an insight about your skatey 800 circuit board limits. You might as well look at their lithium version (if they have one) and try to figure out whenever the electronics is the same…

Or - you could ask someone who is having the same board

Or - you could try to ask '‘skatey company’ itself, perhaps they are willing enough to help out

OR - you could try to look at the capacitors on the circuit (if there are any!) and try to figure out will they accept 49v instead of 45v (but I think this is not a reliable method at all!)

BTW - @mountainboardlover69 did you measure the highest voltage for your battery yourself?

I looked up how much volts per cell lead acid has… It states that basically, 1.75v per cell is empty and 2.4-2.45 is full. Nominal is 2.0v. So to get 36v nominal, there are 18cells.

At 18cells - 2.40x18 = 43.2v

So im not so sure anymore about 45v but if you got from somewhere that it is still safe, you might try with 11s and 4.1v charge, as I said earlier…

Otherwise… 10S would definately be safer, if max voltage is actually 43.2v

You can try to ‘‘feel’’ what the max speed is when battery is half to empty… that’s what speed you would probably also get with Lipo’s. lipo - (10x 3.6-4.2v = 36v-42v.) / 38 avg - / 37v nom PB - 18x 1.75-2.4v = 31.5- 43.2v) - ~37.6/38v average. / 36v nom

1 Like

tnx for alll the ideas i have a 80w lipo charger and if the batterys are full my volt metter sais it is 44.5v and the battery say there max volt is 15 v a piece soldering is not that hard for me i lookt on the site and they sell a 36v 12ah lipo that one but i will never pay 800 euro for a 12ah 36v lipo and here is the board that is in my board i dont see a capacitors i am gone give them a call today

You might wanna take a look at this:

Then decide do you want to remove one cell from the 6s pack to make it 5s…

Anyways, im not sure, but perhaps someone with more electronics knowledge could tell whenever you can over-volt the esc… but generally it seems it does not work that great :slight_smile: But to decide / see if it can take higher voltage, the ‘‘components’’ side should be seen.

In the picture you gave there are only circuit pathes no components on that side of the board…

– So yeah, if you can, just stick to de-soldering one cell… then you can cut balance connector a bit (so it fits 5s) port and stick in 5s port of that turnigy charger you got… You will need to come up how to charge such battery… so you either do 5s x 2 and later charge them in parallel, or you do 5s x 1 and 6s x 1 and then charge seperately…

Also would advise to get 10ah + size battery :slight_smile:

i was planing on getting a 16ah so

1 Like

That should be ok, for such board! I think 8-10ah is the minimum for emtb! :slight_smile: Not sure how much energy your board eats… but I can only do about 8-10km with my 8ah pack… have not tried to go full distance so that is the max calculated one…

So you should be good for about 15km for sure :slight_smile:

– With 10s = 3.7x10 = 37v x 16 = 592 WH 592 WH / ~20wh (~15-20kph avg speed) = ~29 KM

Ok so Im not sure will you really get this much, but 15 - 20km should be really possible!

1 Like

around per 3 ah 5 km

1 Like

not sure about that… depends on voltage, too (6s-12s…)

Forgot to mention - I have 6s, so only 24v

For energy you got to calculate WH

that is 24v X 8Ah = 192 WH, energy use per 1km = ~20 WH 192 / 20 = 9.6km

(usually WH is calculated from 3.6v (nominal) x 6 = 21.6v, but 24v is also ok for calculation)

i am just saing my battery hase 3 ah at this moment in i can max drive 5km wit it

i have a wat metter on my board i will look today i am in school now :sob:

Oh cool. ! Definately try to measure how much kilometers can you drive at what speed!

for me 1km = (~0.9ah*21.6v) = ~19.5 Wh

You can check my previous post - I think you will be able to do even about 20km, since your voltage will be higher! I did calculation for 10s, 11s should be a bit more higher/bigger distance.

for me it is 23wh

there u go

sorry that there is no gopro film but my gopro in empty but after 1.1 km it used 23wh and after 3.5 km 78wh

You should enable ‘‘auto-pause’’ function (if there is one) for your distance app! Otherwise you get incorrect average speed reading!

Did you stop for a lot of time while riding? Im asking this, because at the end your avg speed was 13kph and consumtion is also based on speed!

Otherwise, 22-23wh seems reasonable, even with that ~15kmh average speed. Though I saw you rode over past 30kmh a couple of times… :slight_smile: that’s quite speedy I think…at least for such emtb board

So from this you should be able to calculate the max range you should get!

Take your battery’s voltage:

10s = 37(lipo), 11s=40.7(lipo)

Then multiply (*) that by the size of the battery you intend to use, in your case: 16Ah (can take less, as perhaps not all capacity is gonna be used!)

So that brings us to:

37v X 15AH = 555 WH + 37 WH (max in theory) / 40.7V X 15Ah = 610.5 WH + 40.7 WH (max in theory)

10s / 15ah = 25km 11s / 15ah = 27.75km

– If you go faster, you will probably be able to drive less kilometers

yes i know but there is non and i needet to srap my hole 6.4 inch phone to my board that aint easy

hah for sure…

so yes, go pro video would have been nice! Try to charge you camera before you go riding the next time! Video + App (distance) video would be nice

  • can you tell / show what wattmeter do you have?

Did you install it by yourself ? or it was there already?

this one and u put it in my self