KS-16 680Wh Jittery Ride

[Chriull]

Just some more details so one can follow the cascading/paralleling differences:

The main parts of the schematics of the BMS:

http://forum.electricunicycle.org/topic/459-electric-unicycles-bms-problem-and-solution/

As far as i know thats about what most EUC BMS use. Just ?older ? Gotways have replaced the T1 Mosfets (overdischarge protection) with a blank wire and ?some older? Kinsongs with a ?40A? fuse. (don't know if the newer KS/Gotways are still like this, except the new KS distributed and configured by @1RadWerkstatt of course)

And here plus the following posts @Craniumstudied the internals of the ninebot one BMS (especially the used controller IC):

http://forum.electricunicycle.org/topic/2247-decrease-charging-time-5a-high-current-charger-mod/?do=findComment&comment=29975

So the discussion here is how to "parallel" packs with either:

- connecting all P+, P-, C+, C- together (each to the corresponding of the other packs). As mentioned before by this the overvoltage protection realised by X1 is "shorted". Also if looking at the ninebot thread from Cranium some other safety mechanism like cell over temperature shutoff is "shorted" by this configuration.

- cascading - connecting the P+, P- of one pack to C+, C- of the next pack. The first pack is connected to the charger by C+, C-. The last pack in the cascade is connected with P+, P- to the mainboard. Here the battery packs are also in parallel like with the other configuration. Important with this configuration is, that only the first pack (with the connection to the charger) has a voltage inversion protection, and all the others have the overvoltage protection side capable of handling the driving current for the wheel.

Advantages: If any BMS monitors an unsafe state (battery cell overvoltage, overtemperature, etc) and it cuts the charging input with X1 charging is definitely stopped! Imho thats very important, especially once the cells ages and start to fail - without this protection shorted by the first method headlines of burning EUCs could easily come up....

[someguy152]

On 8/1/2016 at 6:21 AM, US69 said:

they Charge the 680wh block...

The charging goes to the 680wh block...and this block charges the two 340wh blocks.

if the word they refer to the two 340wh blocks, this sentence seems to be saying each one charges the other up.

this is important for me as im trying to fix my 18s battery issues.

i removed the top pack already