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Does MCM4 have bluetooth speakers?


alexbot

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30 minutes ago, Michael Vu said:

Did you want bluetooth speakers? The Kingsong 14C is a comparable wheel to the Gotway MCM4 with decent bluetooth speakers.

They're not essential, I was just wondering. There are a few other reasons that led me to the mcm4 hs over the KS 14C

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44 minutes ago, mich said:

Can you elaborate on the advantages of mcm4 vs KS 14C? 

Sure.

 

1) I had read that there may have been some trouble riding uphill on the kingsong. I believe it was @Kevin Lee who wrote about this

2) I only need a 340 wh battery, which is much harder to get for KS

3) I like the gotway wheel design more and was impressed by the water test video they showed (while I love the speakers on the KS, the exposed holes make me nervous.)

 

There are definitely features of the king song that I liked better as well. In the end, its a choice between 2 great wheels and you cant really go wrong. 

 

I ended up with the HS version, which is the only one id recommend at this point.

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3 minutes ago, alexbot said:

Sure.

 

1) I had read that there may have been some trouble riding uphill on the kingsong. I believe it was @Kevin Lee who wrote about this

2) I only need a 340 wh battery, which is much harder to get for KS

3) I like the gotway wheel design more and was impressed by the water test video they showed (while I love the speakers on the KS, the exposed holes make me nervous.)

 

There are definitely features of the king song that I liked better as well. In the end, its a choice between 2 great wheels and you cant really go wrong. 

 

I ended up with the HS version, which is the only one id recommend at this point.

It's the battery configuration and how the battery packs are connected to each other. It was @zlymex mentioning the serialisation of the packs. You discharge the first pack and the second pack is not in parallel it's connected on the charger port of the first pack. So you will not have 100% capacity of all battery packs for load conditions. That was the rason i stepped out with the KS on evaluation and bought the MSuper. My wife will get a KS 16 but she's not a heavy weight rider, so it's not an issue.
Second there was an issue with at least older mainboards with overheating on KS14 and KS18. I thinks that was improved. But KS has shown on CES a mainboard with active cooling fan. So it looks there's an inefficiency issue (wasting power in heat) over the Gotway mainboard. But this is guessing from my side only.

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1 hour ago, OliverH said:

It's the battery configuration and how the battery packs are connected to each other. It was @zlymex mentioning the serialisation of the packs. You discharge the first pack and the second pack is not in parallel it's connected on the charger port of the first pack. So you will not have 100% capacity of all battery packs for load conditions.

This imho is not fully right. They are "almost" paralleled - there is just the charge protection circuit (for overvoltage protection) and a inverse polarity protection diode inbetween the packs.

So in "normal" conditions, you should get (almost) the full power out of the packs - just with the risk that the charge protection circuit could fry and the last pack has to continue alone.

Once regenerative braking happens, only the last pack (nearest to the motor) gets charged ("helps" braking) and then has to drive the motor alone, until the voltage drops a bit, so the other packs can deliver power again.

Imho depending on the battery configurations for this two brands there exist some with real parallel packs and this daisy-chained packs...

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Almost paralleled sounds like Marketing.

What I've realised on a tour with a KS18-500W 680 Wh (the android only mainboard): Really low charging on downhill tracks. I had to switch with a light weight rider his Firewheel because battery was drained on half of the tour. Never had this problem with MSuper and Firewheel.

So for me it looks like either regenerative braking is bad on KS or they charge one battery pack after each other that you don't charge all battery packs at the same moment.

In the moment when the first (connected to the mainboard) is drained by load it will charged/ assisted at the same time by the second battery, the second by the third and so on. If both have 340 Wh do you have the double capacity or a couple of % more capacity or do you only prevent voltage drop with a bit more capacity? How much capacity can a KS18 1300 Wh deliver as a burst and constant mAh/ Wh (yes one cell is 2C to 10C)? Is the first battery pack more stressed than the other battery packs?

Is there a difference under load with almost vs. real paralleled? Is there a safety issue? This question was never answered in all the threads before. So I decided to buy for me a real paralleled setup because of my weight and driving inclines.

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6 minutes ago, OliverH said:

What I've realised on a tour with a KS18-500W 680 Wh (the android only mainboard): Really low charging on downhill tracks. I had to switch with a light weight rider his Firewheel because battery was drained on half of the tour. Never had this problem with MSuper and Firewheel.

So for me it looks like either regenerative braking is bad on KS or they charge one battery pack after each other that you don't charge all battery packs at the same moment.

In because of the inverse polarity protection diode _only _ the one pack nearest to the motor can be charged. He has then a higher voltage as the other packs and so the inv.. pol.. prot.. diode blocks off the other packs - they will neither be charged nor can they provide their power, until the voltage of the main pack drops again...

6 minutes ago, OliverH said:

In the moment when the first (connected to the mainboard) is drained by load it will charged/ assisted at the same time by the second battery, the second by the third and so on.

It is (almost only*) assisting and not charging. But the pack nearest to the motor will be the "most drained", and the further one looks along the chain, the more capacity stays in the packs, since with each step you have a small voltage drop along the diode and protection circuit.

6 minutes ago, OliverH said:

 If both have 340 Wh do you have the double capacity or a couple of % more capacity or do you only prevent voltage drop with a bit more capacity?

With two packs of 340Wh in parallel you have the twice the capacity. And you prevent voltage drop (during heavy load peaks), since also the internal resistance is halfed. The "normal" voltage drop during the whole discharge cycle is "slower" since you have twice the capacity to be used...

By daisy chaining one should loose a bit of the capacity which would be possible with real parallel packs. (in because of the voltage drops along the protection circuits - so if the first pack is empty (too low voltage) and the EUC stops, the other packs still have some reserve)

6 minutes ago, OliverH said:

How much capacity can a KS18 1300 Wh deliver as a burst and constant mAh/ Wh (yes one cell is 2C to 10C)?

Interesting question - but i am afraight quite hard to answer without the right equipment. There were some power graphs measured with logging devices while riding - was imho also from a KS, but i don't remember if it was the 1300Wh version... Under heavy load one could study the exact behaviour more in detail of this daisy chained vs. parellel packs.

6 minutes ago, OliverH said:

Is the first battery pack more stressed than the other battery packs?

A bit - it has to take the regeneratice breaking energy. Otherwise while "normal" operation it gets the lowest charge and is the first to get depleted - so in average (without regenerative breaking) it should have about comparable charge/discharge cycles as the other packs. (with the little surplus as written below)

6 minutes ago, OliverH said:

 Is there a difference under load with almost vs. real paralleled?

Real paralleled each pack provides the same amount of power for driving. Daisy-chained could/should have a bit of a current limiting between each step, so the first pack provides the most power for higher loads (And gets charged by this difference by the following packs in times of low load)

6 minutes ago, OliverH said:

Is there a safety issue?

Imho the charge protection circuit is not really designed for peak loads happening while driving and could fry. But that only would lead to loosing the capacity of the packs behind - the other packs will still power the motor and one can drive on (maybe without noticing anything - just real charging at home is not possible anymore.) 

6 minutes ago, OliverH said:

This question was never answered in all the threads before.

Unfortionately not - but could be that @KaleOsaurusRexand/or @Jason McNeilare in touch with KS/awaiting their answer after this discussion here:

I can not imagine any advantageous reason for daisy chaining - the manufacturers are just saving one cable and some connectors. But they have to deal with all this problems caused by the charge protection of the BMS...

I am awaiting with interesst an answer from KS - it is hopefully in progress after the above linked thread.

6 minutes ago, OliverH said:

 

So I decided to buy for me a real paralleled setup because of my weight and driving inclines.

Good decision. 

 

 

*) here is the almost again ;) . By the forward diode characteristic there could be some current limiting happening, so that there is no full assist and also a bit of charging while and after peak loads...

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