About time Dual 1000 watt bosch batteries to be retro fit

[Mac_user82]

hi

I think it about time the Bosch dual battery 1000 watt should be retro fit
so that all the dealers can install them to customers ebikes.

instead of just Riese & Muller haven all the crumpet!!!

Personally i would really enjoy haven a dual battery system on my bike
it would come in very handy for my needs.

Anyone thinking the same

 

[Danidl]

hi

I think it about time the Bosch dual battery 1000 watt should be retro fit
so that all the dealers can install them to customers ebikes.

instead of just Riese & Muller haven all the crumpet!!!

Personally i would really enjoy haven a dual battery system on my bike
it would come in very handy for my needs.

Anyone thinking the same

Yes. It also should not cost that much, just being a bracket and a few cables, .. but on that, I would expect to be disappointed.

 

[Mac_user82]

Yes. It also should not cost that much, just being a bracket and a few cables, .. but on that, I would expect to be disappointed.

i have seen the cable kit for it which some places are selling and it is costing about £80 quid to buy the cabling to do it but then states that
it is not available for retro fit

 

[Mac_user82]

I can never understand why companies are advertising the wires if it states that it cannot be used for a retro kit at all pretty pointless

It like you haven a coffee shop and when people walk in oh we only serve tea here we don't sell coffee here at all

 

[soundwave]

http://www.pro-cycling-golla.de/Akku-Rahmen/Kit_Dual_Battery_Y-Kabel_1xRahmen_1x_Gepaecktraegerakku_artikel588397e2864d6.html

 

[RobF]

There's a bit more to dual battery than meets the eye.

A factory installation supports on bike charging, which charges the batteries alternately, switching between each one every few minutes.

In use, the system takes a bit from each battery in turn, again switching every few minutes.

I've no idea if all Bosch bikes have software to support that, but I suspect there's bit more to retrofit than just the loom and second battery holder.

 

[Danidl]

There's a bit more to dual battery than meets the eye.

A factory installation supports on bike charging, which charges the batteries alternately, switching between each one every few minutes.

In use, the system takes a bit from each battery in turn, again switching every few minutes.

I've no idea if all Bosch bikes have software to support that, but I suspect there's bit more to retrofit than just the loom and second battery holder.

Well in that case, it would cost a little more. A 20amp contact relay and a timer easy to fit into the cable loom.

 

[trouty]

Just buy a spare battery and shove it in your back pack

 

[Mac_user82]

Just buy a spare battery and shove it in your back pack

i do own two batteries and struggling a little bit of range i was thinking the dual battery might be better for my needs because it takes 5% then swaps to the other batteries

i have just bought a new cassette with a completely different gear ratio i am hoping this will solve my problem when i am going up the hills and not drain the battery so quick and fingers crossed get better mileage too

 

[soundwave]

the batts are in parallel so both will drain at the same time and also self balance them self out if 1 has more charge than the other.

so as far as i can see no software is used for this to use 2 batts as 1.

 

[Trevormonty]

the batts are in parallel so both will drain at the same time and also self balance them self out if 1 has more charge than the other.

so as far as i can see no software is used for this to use 2 batts as 1.

Reviews I've read says it switches every 5%. Not sure what happens if one battery is 50% and other 100%. Does alternate or wait till 100% is down to 50%. NB you can't parallel batteries up, not without balancing and control circuits. Hence switching, which is very easy to do.

 

[Deleted member 4366]

Reviews I've read says it switches every 5%. Not sure what happens if one battery is 50% and other 100%. Does alternate or wait till 100% is down to 50%. NB you can't parallel batteries up, not without balancing and control circuits. Hence switching, which is very easy to do.

They have to protect against dunderheads clipping in a second battery that's at a different voltage than the first. Personally, I think it would be a lot simpler to have a second carrier for a not connected battery, and then swap them over manually when the first is empty. Carrying a spare battery in a rucksack is a right pain, literally.

 

[RobF]

They have to protect against dunderheads clipping in a second battery that's at a different voltage than the first. Personally, I think it would be a lot simpler to have a second carrier for a not connected battery, and then swap them over manually when the first is empty. Carrying a spare battery in a rucksack is a right pain, literally.

Being able to charge both batteries from one plug on the bike is neat, saves some battery un-locking and handling.

Not having to change batteries on the road is also convenient.

Experience tells me battery one often conks out at an inconvenient moment, on a hill, or a few miles after a lunch stop, but the lunch stop was a bit too early to change.

The way the system sips alternately from both batteries means neither battery is left fully charged for longer than needed.

The twin battery system is not magic, but it is a neat solution for those of us who want extra range.

Another point to consider is buying a twin battery bike - assuming you get a discount from the retailer - means you get battery number two at the factory installed /discounted price, which should be more cost efficient than buying one later.

 

[soundwave]

2 lipo and 4 18650 cells all in parallel and a pcb power bank usb for charging it.

if i remove any cells they are all the same voltage as they self balance them self, if i take 1 out and drain it and put it back in the pack the other cells will charge it until the hole pack reaches the same voltage again.

 

[Danidl]

They have to protect against dunderheads clipping in a second battery that's at a different voltage than the first. Personally, I think it would be a lot simpler to have a second carrier for a not connected battery, and then swap them over manually when the first is empty. Carrying a spare battery in a rucksack is a right pain, literally.

There are any number of protection schemes which would prevent that from inserting a low forward voltage drop diode in both output power leads or using an old fashioned relay. Nobody should be carrying weight on their back in a rucksack, in any event panniers were invented for that...

 

[Danidl]

View attachment 18553

2 lipo and 4 18650 cells all in parallel and a pcb power bank usb for charging it.

if i remove any cells they are all the same voltage as they self balance them self, if i take 1 out and drain it and put it back in the pack the other cells will charge it until the hole pack reaches the same voltage again.

. Yes but that is potentially a bad way to do it. If a number of cells are put in parallel, they will share charge and eventually reach an equilibrium voltage. If one of the cells is initially lower in voltage and all the rest are at full voltage , the current which will flow into that cell will be very high , limited only by the internal resistance of the cell. Functionally it would be little different than shorting a fully charged cell by putting a metal strap accross it.
To put numbers on it say you had 10 cells each at 4.2v, and one cell at 3.0v, and the resistance of each cell was 20milliohm. Then the 10 cells would be supplying 4.2v from a source resistance of 2milliohm . The current which would flow would be (v2- v1)/resistance. Or 1.2/22milliohm. Or 60amps.
This current will not flow for very long, as the cell charges but could be damaging. However the charging time will be longer than the ratio of current to normal charging current might suggest because the take-up of ions will not be optimal and the extra energy goes into heating the cell.

 

[soundwave]

http://www.pedelecforum.de/forum/index.php?threads/performance-extenderakku-anschließen.33512/page-2#post-521535

 

[DroidOne]

Is retrofitting a secondary Bosch battery pack still not possible? Or are there any dealers out there who can/will do it?

 

[soundwave]

you can buy the cable and try it ur self but i doubt any dealer will fit it for you as will void any warranty.

all the cable does is put the 2 batts in parallel so it is just 1 big batt with 1000w.

 

[DroidOne]

you can buy the cable and try it ur self but i doubt any dealer will fit it for you as will void any warranty.

all the cable does is put the 2 batts in parallel so it is just 1 big batt with 1000w.

When searching for the cable, I noticed that e-bikeshop says:

Please Note: Retrofitting is not compatible with non DualBattery bikes, this has to be done in-house by our specialist eBike technicians with access to diagnostics to reformat the bike.

So the installation might not be as simple as just getting the cable and plugging it in I guess. I'll probably have to find a dealer nearby who knows how to do it.

But it seems to be possible at least, which is great.