Securing extra battery to Moscow Plus

[Silvercat]

Hi,
I recall reading that long time member John Peck rigged a battery support holder to carry an extra battery. He is obviously very talented.
Any suggestions would be appreciated. And, the pros and cons of carrying that extra 9 pounds.
Also, would the 48 volt 18 amp be much better than the 16 amp battery?
I understand the weight capacity of the bike is 275 pounds. Does that include the 57 pounds of the bike weight or just the rider?
I also had one local high end bike shop tell me that they will not work on my bike, even simple basic adjustments! They told me that the cables prevent my handlebar from being raised!! Total BS as far as I am concerned. I could use about a 5 inch height increase.
Thanks folks!

 

[kmccune]

Brake cables ad nausea ever consider a "bmx" style handlebar?
On the battery question, a little or a lot( it all depends on the battery manufacturer you got- with respect "renuzit")
Gross weight is total weight of bike and add ones including rider.
Tare weight empty weight of bike
Net weight is what you can add on the bike or haul within weight limit, I expect 275# is the recommended gross weight.
Have you given that bike a road test yet? 16AH is a pretty sizable battery, you can always mount a "cargo rack battery' of 10 ah or so and parallel it, be advised any weight added higher on the Bike will affect handling.

 

[Silvercat]

Hi,
Thank you.
I think it might be best to check with a local ‘good’ bike shop so that they can see my bike in person.
I do not want to significantly change handling characteristics.
And, re an extra battery, certainly a trade off re weight and convenience. I wish there were much lighter battery options available...perhaps down the road?
Thanks again!

 

[kmccune]

Merry Christmas!, remember this", it is going to get better". Grin has some nice range extender battery packs @ 36 volts.

 

[Fred]

Hi,
Thank you.
I think it might be best to check with a local ‘good’ bike shop so that they can see my bike in person.
I do not want to significantly change handling characteristics.
And, re an extra battery, certainly a trade off re weight and convenience. I wish there were much lighter battery options available...perhaps down the road?
Thanks again!

I rigged up a mount for a 2nd 13Ah battery to go with the installed 16Ah pack. My intent was to take along the 13Ah pack if I knew I was going on a long trip. It all works fine, but I am finding that I can do in the neighbourhood of 80-90 Km with just the 16Ah pack and the amount of pedaling I like to do. Frankly that's about as much as my butt can take, so I'm not sure I will ever use the auxiliary pack. My bike is a step-thru model, so my approach to mounting the aux pack may be different than others. If anyone wants a pic, I can attach it.

 

[kmccune]

I rigged up a mount for a 2nd 13Ah battery to go with the installed 16Ah pack. My intent was to take along the 13Ah pack if I knew I was going on a long trip. It all works fine, but I am finding that I can do in the neighbourhood of 80-90 Km with just the 16Ah pack and the amount of pedaling I like to do. Frankly that's about as much as my butt can take, so I'm not sure I will ever use the auxiliary pack. My bike is a step-thru model, so my approach to mounting the aux pack may be different than others. If anyone wants a pic, I can attach it.

I actually had to come to grips with what I actually needed and would use. I did order a "Big Bear" I like regen it helps you go down these steep inclines around here at a reasonable rate( helps keep "chill factor" and blurry vision to a reasonable level)

 

[kmccune]

Parallel is easy(use same voltage batteries) and simply incorporate the same polarity wires together it is easy to find parallel XT combiners.
MAKE SURE YOU DO NOT SHORT ANYTHING! these batteries can dump a lot of current fast( you can find out what a plasma is) if unsure get someone to show you that knows about such things

 

[kmccune]

I thought it was simple as connecting them too, by using connectors sold on AliExpress.

1.99US $ |Xt60 Female To 2 Male Parallel Battery Connector 14awg 10cm 100mm Silicone Cable Extension Y Splitter For Rc Lipo Battery - Parts & Accs - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

1.99US $ |Xt60 Male To Dual Female Parallel Connector Y Splitter Cable Wire 14awg 1 Male To 2 Female For Rc Lipo Battery - Parts & Accs - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

The reason why I posted the WattWagons dual battery converter was because, some people have experience problems.
I can't remember why, maybe because two BMS could not work simultaneously?

each pack has to be charged to the same level, perhaps if the cells are radically different it will not work right( kinda like trying to mix Diesel and gasoline?) It will be nice if we ever get a Hi performance battery that doesn't require cell balancing. And its probably a good idea to use batteries from the same manu and type, I do not know if you could"filter" the current with a diode.

 

[Fred]

Although I don't profess to be an expert on this, I can share my understanding and experience with using 2 batteries on a bike, there are essentially 2 approaches:

1. Connect the two in parallel so both are used at the same time​
2. Use one at a time by manually switching one in and the other out​

1. The parallel approach

• The +ve side of one battery is connected to the +ve side of the other; ditto for the -ve terminals
• It is important that the two batteries start out at the same voltage. Otherwise there is potential for the higher voltage one to rapidly discharge through the discharge ports of the lower voltage one causing damage from the unexpected high current.
• This risk can be mitigated by installing diodes on the +ve leads of both packs, allowing current flow in only one direction. These diodes must be spec'd to be able to support the max current expected from one battery.
• That WattWagons dual battery converter mentioned above probably has diodes and perhaps some other circuitry as it permits voltage mixtures of 52V and 48V. However, I have enough gadgets on my bike and don't need another!
• One benefit of this approach is that because they are in parallel, each battery is delivering only half the load demanded by the controller. This lower amp discharge is easier on the cells and may extend their life.

2. The one at a time approach

• When one battery is depleted (or anytime you want) it is "unplugged" from the controller and the "spare" is plugged in.
• This plug-in/plug-out can be done simply just using the connectors.
• It can also be done by a using a SPDT switch by making the -ve terminals ground and joining them together and connecting the +ve terminals to the poles on the switch. We need to be sure to source a switch capable of carrying the needed current.
• The benefit of this approach is that when one battery is drained you know where you stand and that you are now running on the spare capacity of the 2nd battery. Or if both packs are the same capacity, you know you have used about half the total you have on board. (I don't know if anyone is old enough to remember the early VW Beetle that had no gas gauge and when you ran out, you could switch to a second small "spare tank" with enough in it to hopefully get you at a gas station.)

Anyways hope this is useful and there may be other ways or ideas on how to do this.

 

[Decrepidude]

Hi,
Thank you.
I think it might be best to check with a local ‘good’ bike shop so that they can see my bike in person.
I do not want to significantly change handling characteristics.
And, re an extra battery, certainly a trade off re weight and convenience. I wish there were much lighter battery options available...perhaps down the road?
Thanks again!

I've spent a great deal of time pondering this issue, and besides the cost of the battery, I've decided that if I go forward, I would not parallel a second battery. If you don't go marathon trekking every day, you're just weighing down the bike and reducing its efficiency. The beauty of getting another battery is that on the occasions you really need more range, you can bring it with you and just swap it out when your original runs down.

 

[Bitmugger]

I've spent a great deal of time pondering this issue, and besides the cost of the battery, I've decided that if I go forward, I would not parallel a second battery. If you don't go marathon trekking every day, you're just weighing down the bike and reducing its efficiency. The beauty of getting another battery is that on the occasions you really need more range, you can bring it with you and just swap it out when your original runs down.

That is going to be my approach. Paralleling them has advantages but the simplicity of a battery swap appeals more. and avoids issues of voltage differences between battery packs.

Bear in mind paralleling them is more efficient than one at a time but the difference is probably slight. Meaning by paralleling two batteries you'll effectively use less current from each battery and most batteries (at least seal lead acid that I am more familiar with) will have a higher ah capacity at a lower avg discharge current. I haven't seen a graph of total mah vs discharge rates for any LiPo packs I've seen advertised but they are common when shopping for lead acid so it might be more a lead acid thing.

 

[kmccune]

I've spent a great deal of time pondering this issue, and besides the cost of the battery, I've decided that if I go forward, I would not parallel a second battery. If you don't go marathon trekking every day, you're just weighing down the bike and reducing its efficiency. The beauty of getting another battery is that on the occasions you really need more range, you can bring it with you and just swap it out when your original runs down.

Check out "Luna Cycle" I Believe they have some smaller high-powered units, think"Grin" may have a couple.

 

[kmccune]

Although I don't profess to be an expert on this, I can share my understanding and experience with using 2 batteries on a bike, there are essentially 2 approaches:

1. Connect the two in parallel so both are used at the same time​
2. Use one at a time by manually switching one in and the other out​

1. The parallel approach

• The +ve side of one battery is connected to the +ve side of the other; ditto for the -ve terminals
• It is important that the two batteries start out at the same voltage. Otherwise there is potential for the higher voltage one to rapidly discharge through the discharge ports of the lower voltage one causing damage from the unexpected high current.
• This risk can be mitigated by installing diodes on the +ve leads of both packs, allowing current flow in only one direction. These diodes must be spec'd to be able to support the max current expected from one battery.
• That WattWagons dual battery converter mentioned above probably has diodes and perhaps some other circuitry as it permits voltage mixtures of 52V and 48V. However, I have enough gadgets on my bike and don't need another!
• One benefit of this approach is that because they are in parallel, each battery is delivering only half the load demanded by the controller. This lower amp discharge is easier on the cells and may extend their life.

2. The one at a time approach

• When one battery is depleted (or anytime you want) it is "unplugged" from the controller and the "spare" is plugged in.
• This plug-in/plug-out can be done simply just using the connectors.
• It can also be done by a using a SPDT switch by making the -ve terminals ground and joining them together and connecting the +ve terminals to the poles on the switch. We need to be sure to source a switch capable of carrying the needed current.
• The benefit of this approach is that when one battery is drained you know where you stand and that you are now running on the spare capacity of the 2nd battery. Or if both packs are the same capacity, you know you have used about half the total you have on board. (I don't know if anyone is old enough to remember the early VW Beetle that had no gas gauge and when you ran out, you could switch to a second small "spare tank" with enough in it to hopefully get you at a gas station.)

Anyways hope this is useful and there may be other ways or ideas on how to do this.

Series-parallel can get rather"interesting".

 

[kmccune]

Okay so, looks like you will need some kind of module to make parallel connection work.

Each battery pack will contain BMS, each pack may have different cells, simply connecting two can't be a good idea.

Area 13

boltonebikes.com

Would imagine the BMS systems may have conflict.

 

[6zfshdb]

I usually carry two batteries on long rides just in case. Most of the time, I don't need the second one and I only have to recharge the primary. If I had the batteries in parallel, I would have to recharge both after every ride. This means you need two chargers or run the risk of forgetting to swap batteries with a single charger.