Anyone pack along an extra, second battery? What about a "reserve tank"?

[NaturallyRC]

Probably this has been asked before (a lot) but does anyone pack a second battery for long rides? Thing is, I wouldn't dream of heading to the woods to do some RC rock crawling without at least two lipos -- one for the trip out; one to get back to the Subaru. What about a smaller than normal (say, 10km) ebike battery for emergency situations? That would be cool. Cheers.

[ericwn]

I haven't yet but I'm hoping to do some longer rides with my kids this year and I might just buy a second stock Rad battery and put it somewhere in the wagon.

I'm in fact toying with the idea of getting a second Rad bike as the included battery is already half the price of a new bike.

[Si1Dia]

I have modified my Rover 6+ so I can run 3 batteries in parallel.

I use the DATEx3 from BGB: https://biggamebikes.com/product/datex2-parallel-battery-adapter , to connect the three batteries safely.

I got two standard Rad battery trays from eBay, and a set of dead Standard batteries that I refurbished. ( I got lucky with both batteries, they had bad solder connections )

I had to do some creative splicing and voided my warranty, I'm sure, but this bike runs like a beast.

The pictures show the bike with the 2 battery Area 13 Parallel connector: https://boltonebikes.com/collections/electrical-accessories/products/dual-battery-parallel-connector. This is a great connector, but I have since moved it to my wife's bike.

With the 3 batteries in Parallel, I have an average voltage drop of 1.5 volts at 750w. This equals excellent hill-climbing capabilities.

As for range? When mostly in PAS 5, I have pushed it to 65 miles. This left me with 47v left on the battery, down from my 54.3v starting point. I have not stressed it to empty yet.

Almost forgot. I also added one of these voltage meters in line with the headlight. I did this so I could read full bike voltage, and so I could turn it off/on id I wanted to by turning off/on the headlight.
https://amzn.to/3xUGlsX

[JimInPT]

I had to do some creative splicing and voided my warranty, I'm sure, but this bike runs like a beast.

I'll bet.  And I agree your warranty is poofed, but great job on a very new model.

[Si1Dia]

I had to do some creative splicing and voided my warranty, I'm sure, but this bike runs like a beast.

I'll bet.  And I agree your warranty is poofed, but great job on a very new model.

Rad has already confirmed my voided warranty. but that's okay, this is just a very fun toy for the most part. The best part is though, two replacement parts, under $100, and it is back to stock, once the extras are also removed.

[NaturallyRC]

Wow! Thanks for sharing. My hardhat is off. Similarly (sort of) to get longer run time out of my RC trail trucks, I employ a three-way XT60  harness to run two lipos in parallel. I was warned that one pack might drop dangerously low while the other stays high, but every time I check the voltage (digitally to two decimal places) they are absolutely identical. I'm no battery expert, but I suspect some kind of natural balancing is going on. What have you found?

I have modified my Rover 6+ so I can run 3 batteries in parallel.

I use the DATEx3 from BGB: https://biggamebikes.com/product/datex2-parallel-battery-adapter , to connect the three batteries safely.

I got two standard Rad battery trays from eBay, and a set of dead Standard batteries that I refurbished. ( I got lucky with both batteries, they had bad solder connections )

I had to do some creative splicing and voided my warranty, I'm sure, but this bike runs like a beast.

The pictures show the bike with the 2 battery Area 13 Parallel connector: https://boltonebikes.com/collections/electrical-accessories/products/dual-battery-parallel-connector. This is a great connector, but I have since moved it to my wife's bike.

With the 3 batteries in Parallel, I have an average voltage drop of 1.5 volts at 750w. This equals excellent hill-climbing capabilities.

As for range? When mostly in PAS 5, I have pushed it to 65 miles. This left me with 47v left on the battery, down from my 54.3v starting point. I have not stressed it to empty yet.

Almost forgot. I also added one of these voltage meters in line with the headlight. I did this so I could read full bike voltage, and so I could turn it off/on id I wanted to by turning off/on the headlight.
https://amzn.to/3xUGlsX

[NaturallyRC]

I know, eh. If packs were cheaper, I would have two or three. Broken record, but with my RC lipos, I have half a dozen numbered with a Sharpie, used in rotation. I would never leave the house without a spare (or three). Tough to wrap my head around the ebike battery world where all your eggs are in one basket. Thanks for sharing.

the included battery is already half the price of a new bike.

[Radio Runner]

I always carry a 2nd battery unless its a 10 mile or less trip. Riding a heavy ebike without power is nightmare. Lots of hills here, big ones.

[Tree]

I have modified my Rover 6+ so I can run 3 batteries in parallel.

I could not be more jealous of your set up.

[ericwn]

I have modified my Rover 6+ so I can run 3 batteries in parallel.

I use the DATEx3 from BGB: https://biggamebikes.com/product/datex2-parallel-battery-adapter , to connect the three batteries safely.

I got two standard Rad battery trays from eBay, and a set of dead Standard batteries that I refurbished. ( I got lucky with both batteries, they had bad solder connections )

I had to do some creative splicing and voided my warranty, I'm sure, but this bike runs like a beast.

The pictures show the bike with the 2 battery Area 13 Parallel connector: https://boltonebikes.com/collections/electrical-accessories/products/dual-battery-parallel-connector. This is a great connector, but I have since moved it to my wife's bike.

With the 3 batteries in Parallel, I have an average voltage drop of 1.5 volts at 750w. This equals excellent hill-climbing capabilities.

As for range? When mostly in PAS 5, I have pushed it to 65 miles. This left me with 47v left on the battery, down from my 54.3v starting point. I have not stressed it to empty yet.

Almost forgot. I also added one of these voltage meters in line with the headlight. I did this so I could read full bike voltage, and so I could turn it off/on id I wanted to by turning off/on the headlight.
https://amzn.to/3xUGlsX

So is the reason for this setup mostly range extension? That certainly is some creative wiring there! [emoji846] only thing that matters is the fun you have with it anyway. Thanks much for sharing your photos!

[NaturallyRC]

The reason is so you don't have to stop and switch packs. There's no significant performance upgrade or operational difference that I can think of, apart from running at all five bars three times longer time before seeing a voltage drop, but whether your legs even notice that is a topic for another day. 

So is the reason for this setup mostly range extension?

[Si1Dia]

The reason is so you don't have to stop and switch packs. There's no significant performance upgrade or operational difference that I can think of, apart from running at all five bars three times longer time before seeing a voltage drop, but whether your legs even notice that is a topic for another day. 

So is the reason for this setup mostly range extension?

Besides not having to stop and switch batteries there is a significant performance increase with this setup. You are also putting less stress on the batteries since the three are now sharing the workload.

Once I installed the voltage meter, and when running just the stock battery, I was seeing an 8-9 volt drop when accelerating and when at 750w. That is a lot of power loss that equates to poorer performance when under load. With the three batteries, I am seeing only a 1.5 volt drop under the same loads.

Granted this does not affect the top end speed at all, still capped at 20mph, But the low end, hill climbing ability, has seen the biggest improvement. (I know the speed can be increased a bit, but for me, 20mph is plenty fast enough.)

Where I am at there is a 2.5 mile long 12-15% grade hill going into town. Before I modified my bike I would have to be in PAS 5 and gear 3-4, or lower,  to make it up that hill with work at around 10-13mph. Now in PAS 4, it will easily top out at 20mph on the same hill for the entire distance.

[Altema]

Wow! Thanks for sharing. My hardhat is off. Similarly (sort of) to get longer run time out of my RC trail trucks, I employ a three-way XT60  harness to run two lipos in parallel. I was warned that one pack might drop dangerously low while the other stays high, but every time I check the voltage (digitally to two decimal places) they are absolutely identical. I'm no battery expert, but I suspect some kind of natural balancing is going on. What have you found?

Not sure if the functions are the same with your LiPo's, but with the typical e-bike LiIon batteries, if there is any voltage difference, the lower battery sees it as regen voltage and charges itself from the other battery or batteries. This is what I usually see when running a hardwired parallel connection. When using the DATEx2 or x3, there is no regen since the batteries are isolated from each other. However, the device is smart enough to take power from the higher voltage batteries, then merge the power from other batteries when the voltage matches.

[Altema]

By the way, I run single, double, or triple 52v batteries depending on the range needed, all hardwired in parallel. I have a 90 amp DATEx2, but can't use it with a Phaserunner if top speed overdrive is enabled. I use a single battery if I can get away with it, and with the smallest battery (12.5 Ah), I can still make it to work and back with a single charge. However if I push it past 30mph for long, the battery management starts reducing power by the time I get close to home.

[NaturallyRC]

Good info. Thanks.

Wow! Thanks for sharing. My hardhat is off. Similarly (sort of) to get longer run time out of my RC trail trucks, I employ a three-way XT60  harness to run two lipos in parallel. I was warned that one pack might drop dangerously low while the other stays high, but every time I check the voltage (digitally to two decimal places) they are absolutely identical. I'm no battery expert, but I suspect some kind of natural balancing is going on. What have you found?

Not sure if the functions are the same with your LiPo's, but with the typical e-bike LiIon batteries, if there is any voltage difference, the lower battery sees it as regen voltage and charges itself from the other battery or batteries. This is what I usually see when running a hardwired parallel connection. When using the DATEx2 or x3, there is no regen since the batteries are isolated from each other. However, the device is smart enough to take power from the higher voltage batteries, then merge the power from other batteries when the voltage matches.