About time Dual 1000 watt bosch batteries to be retro fit

[Deleted member 25121]

because bikes with no dual batts need it to be turned on buy a dealer with the bosch software any dealer with it can turn on dual batts same as the lights as turned off if none is fitted.

Yes, presumably the dealer would modify the battery wiring and the firmware.

That doesn't mean that the batteries would be wired in parallel.

Of course they won't be wired in series, LOL.

 

[soundwave]

because bosch batts have smart bms that talks to the motor and charger so in use it will switch between the 2 batts wired in parallel.

you just cant wire it up any other way and is controlled buy the bikes software.

 

[Deleted member 25121]

because bosch batts have smart bms that talks to the motor and charger so in use it will switch between the 2 batts wired in parallel.

you just cant wire it up any other way and is controlled buy the bikes software.

How can it switch between them if they're wired in parallel?

 

[soundwave]

because it is a 36v 1000w batt the software controls what is used for each batts bms and it is also why you can charge both batts with one charger.

 

[Deleted member 25121]

because it is a 36v 1000w batt

There are 2 x 500W batteries, not one 1000W.

 

[soundwave]

There are 2 x 500W batteries, not one 1000W.

same thing as you are just doubling the capacity but keeping the voltage at 36v.

 

[sjpt]

Depends where the switching happens. If it happens locally to the battery then the cable will appear to connect them in parallel, but one or the other batteries will have turned itself off.

It seems possible (hypothesis, not fact) that something after the cables converge has the intelligence to tell the batteries when to turn on and off. It is that that need reprogramming so that it can give switching advice to the two batteries. If you just connect two batteries with the same cable but do NOT reprogram then the batteries will indeed be connected in parallel.

 

[Deleted member 25121]

Depends where the switching happens. If it happens locally to the battery then the cable will appear to connect them in parallel, but one or the other batteries will have turned itself off.

It seems possible (hypothesis, not fact) that something after the cables converge has the intelligence to tell the batteries when to turn on and off. It is that that need reprogramming so that it can give switching advice to the two batteries. If you just connect two batteries with the same cable but do NOT reprogram then the batteries will indeed be connected in parallel.

Actually I suspect that the controller can talk to each battery pack individually, via a serial link, and can turn each pack on and off with the on/off switching being down inside each pack.
The power lines of each pack could then be wired in parallel but I'm not sure whether the serial control lines could be paralleled up.
Either way, the controller firmware would need to be updated if it needed to control 2 packs rather than one.
The point I've being trying to make is that both packs are NOT active at the same time.

 

[soundwave]

and thats why no 3rd party batt has ever been released for bosch motor bikes as if it is not a bosch bms it will not even turn on.

tho if you have a working bms it can now be recelled.

cant find the post anymore but on the german site he got 2 frame batts and a 3rd rack batt so had 1500w worth and it was showing 3 batts on the display as well so it can switch between 3 batts if wired up like that tho imo not supported buy bosch.

 

[sjpt]

Actually I suspect that the controller can talk to each battery pack individually, via a serial link, and can turn each pack on and off with the on/off switching being down inside each pack.
The power lines of each pack could then be wired in parallel but I'm not sure whether the serial control lines could be paralleled up.
Either way, the controller firmware would need to be updated if it needed to control 2 packs rather than one.
The point I've being trying to make is that both packs are NOT active at the same time.

I think we agree completely.

I don't see any difficulty in the serial control lines being paralleled. Once you've got that level of processing and that sort of protocol at all there is no difficulty (except maybe backwards compatibility) in including an address in the protocol.

 

[Deleted member 25121]

I think we agree completely.

I don't see any difficulty in the serial control lines being paralleled. Once you've got that level of processing and that sort of protocol at all there is no difficulty (except maybe backwards compatibility) in including an address in the protocol.

It's difficult to see from the photos of the cable whether there are 3 or 4 wires on the connector going to the controller. These could be battery pack power in/out wire, ground and 1 or 2 control lines. A 1-wire bus can have a master and multiple slaves but the slaves need to have unique 64 bit addresses and I'm not sure how that would be accomplished given that the battery packs can be mixed at random.

Guide to 1-Wire Communication | Maxim Integrated

Our guide on 1 wire communication will evaluate 1-Wire devices, device customization options, serial protocol and more.

www.maximintegrated.com

I'm thinking that whether or not the control lines could be paralleled depends on Bosch's implementation.

 

[sjpt]

A 1-wire bus can have a master and multiple slaves but the slaves need to have unique 64 bit addresses and I'm not sure how that would be accomplished given that the battery packs can be mixed at random.

Guide to 1-Wire Communication | Maxim Integrated

Our guide on 1 wire communication will evaluate 1-Wire devices, device customization options, serial protocol and more.

www.maximintegrated.com

A possible way (I haven't a clue if this is how it is done): each battery has a unique address, and the master queries the slave addresses at power on.

 

[Deleted member 25121]

A possible way (I haven't a clue if this is how it is done): each battery has a unique address, and the master queries the slave addresses at power on.

There might be 65-8=56 address bits available which is 7E16, ie huge, so that could be an option but it could take forever for the controller to scan through that address space looking for batteries when the bike is powered up.
There may be ways around this but we just don't know and it would be unwise, I feel, to assume that the control lines can be paralleled.

 

[sjpt]

No need to scan the address space, just send out a request for connected addresses signal. I absolutely agree it would be unwise to assume that is the way they do it. As you say, we just don't know. I (at least) am
just hypothesizing what they could do.