I have done that and it looks good. I think the 6th group just has slightly higher resistance.
I am thinking the pack just needs to be retired.
its within a 10th of a volt. The only thing its doing bad at the moment is indicating that it WILL be a problem later. In the meantime, if you need to OCD yourself into a pile of battery parts, you can check the individual cell volltages, look for broken welds, check the solder joints on the balance leads, and if that locates the problem, wire in a balance charger and charge each pgroup up to 4.150 after discharging all of them below that.
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Other things to check. Tire pressure if your using Pnuematics. Bearings make sure your wheels spin free. Belt tension not too tight.
Put your back wheels on without the belt like you would normally and check the spin of your wheels. I found out that I had to back off the wheel nuts a bit to relieve the preload on my bearings.
The less resistance=happy battery.
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I forget, how do you get to this screen on the R2
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Go into the more info screen. Than as fast as you can, double click the power button then hold the down button. It is trickey to get the timing right.
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thx…i do remember it being tricky to get.
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I thought the same thing. Someone awhile back even told me I’d be getting 13-ish mile range on a 10s4p but I went with the esk8 calculators which was as you said double the range. So it seems to be the range for that battery running on AT tires.
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In case anyone stumbles across this post in the future wanting to do the same thing, it does indeed work. I ran the cables in parallel between the BMS and ESC, and 3d printed an xt60 mount that goes on the rear truck. Another thing I discovered it that you can just plug in the external battery and run the board off of it as long as you do not turn the power button on, but I would not reccomend it because if the cord gets disconnected you will lose your breaks.
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does anyone know if the 6x2 tires will fit on the evolve AT hubs?
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good information to have…thx
Thank you for the pics. Can you clarify when you splice the external battery between the BMS and ESC it runs only on external battery when board is off but if the board is on it will charge the internal battery at the same time? This does not make sense to me. How is the output amps from the external battery being controlled so that it does not output a dangerous amount when it is charging the internal pack?
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Welcome to the forum!
That is correct. The switch on the board is connected to the bms and you are splicing in downstream of the bms. I dont recommend running off of just an external battery because if it gets disconnected you will have no breaks. To prevent an amp spike to the internal battery you have to turn the bms on and then plug an external battery in that has the same voltage.
The external battery is not charging the internal one, but they are sharing the load and drain equally at the same time. You can not ride the board for a few miles, then plug in a fully charged external battery because that would create a very unhealthy voltage spike.
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Ok that makes sense. I am looking for a solution that i can plug the external battery at any time regardless of the internal battery voltage. I have a large external 10s battery matching my boards 10s battery and would like to simply connect via the boards external charge port but i do not know how to control the amps coming from the external battery. I assume if i dont limit the amps it will be some dangerous high amount coming in, i dont think the boards BMS limits incoming amps from external pack right?
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The bms will not limit the amps, so it will make some magic smoke if you plug in a fully charged battery in to even a half charged board.
What a few people do is get a 9s or lower battery and plug it into a mppt (I used this one on my onewheel before I found the ego system https://www.amazon.com/dp/B073PR56R9/ref=cm_sw_r_other_apa_i_cMFFEb9CR80YP ) and you can control the voltage and amps.
I know you probably want to use the 10s battery you have, but it really wont be easy unless you have a ton of room in a backpack.
Let’s say the board is at 50% and the external battery is at 80%. You would need a buck converter to lower the voltage and reduce the amps.
Now, say the board is at 65% and the external battery is at 45%. You will need a boost converter to get the voltage up high enough that it will charge the board.
So in summary, to use a 10s battery to charge a 10s board, you would need a buck and a boost converter. There are some 2in1 units, but they are extremely large and heavy.
Thank you for the reply! I believe all i would need is a boost converter when the external battery voltage starts falling to keep the 42v incoming volts constant in the 10s example…i dont think i would ever need to buck down the external pack voltage as the incoming 42v would never damage internal battery as long as i keep the amperage under control. External AC-DC chargers always output the max voltage from my understanding regardless of battery voltage starting point?
So i guess what is need is a boost converter to maintain 42v that you can control amps with if those are something that exist.
Maybe i am not understanding how AC-DC chargers work but i am pretty sure they dont adjust voltage based on battery starting voltage.