Voliomart 1500 watt hub motor- How much can I over volt.

[toddbailey]

Hi all
having a bit of trouble with hill climbing and thinking of reworking the battery pack
for starters I have 4 12v 16 amp/hr miady lifepo4 in series
I'm going to rebuild the pack with a beefier smart battery controller namly a

100BALANCE BMS 60A Active Balance 1A 8S-24S Build in Bluetooth Cell Balancing Smart PCB Battery Protection Board for Li-ion/Lifpo4/LTO Lithium Battery Pack​

on amazon https://www.amazon.com/dp/B0CQZLTWNG?ref=ppx_yo2ov_dt_b_fed_asin_title

the batteries also on amazon

Miady 12V 16Ah Deep Cycle LiFePO4 Battery, 2000 Cycles LFP16AH Rechargeable Maintenance-Free Batteries for Golf Cart, Boat, Solar System, UPS etc​

Hope posting links isn't violating any rules,

Anway these batteries are made using 2 amp/hr cells in a 4s8p config

When wired up I get apx 51 volts.- 4 12 volt batteries in series. I suspect that I don't get enough amps for hill climbing.

My plan is to rebuild the pack in a 17 or 18 S and 10 p config - approx 58 or 62 volt and 20 amp/hr

Questions:
Will 62 volts be too much voltage Voliomart tells me 32 to 60 volt range.
Will a 20 amp/hr with the beefier battery controller help with my hill climbing?
Should I add more in Parallel? ie 22/24/26 amp hr etc?
My charger is maxed out at 61 v, is this gonna be a problem is I go with 18s (again 3.2v lifepo4 cells)
Don't care about going faster 35 mph on a mountain bike is fast enough for me, I more concerned about getting up the hills. fwiw I weigh 200. bike is about 40. road slope is about 40 at times

Thanks

 

[hillslayer@]

Add a mid-drive and fly uphill without worrying about overheating either motor.

 

[E-HP]

I have 4 12v 16 amp/hr miady lifepo4 in series
I'm going to rebuild the pack with a beefier smart battery controller namly a

100BALANCE BMS 60A Active Balance 1A 8S-24S Build in Bluetooth Cell Balancing Smart PCB Battery Protection Board for Li-ion/Lifpo4/LTO Lithium Battery Pack​

on amazon https://www.amazon.com/dp/B0CQZLTWNG?ref=ppx_yo2ov_dt_b_fed_asin_title

the batteries also on amazon

Midas 12V 16Ah Deep Cycle LiFePO4 Battery, 2000 Cycles LFP16AH Rechargeable Maintenance-Free Batteries for Golf Cart, Boat, Solar System, UPS etc​

Hope posting links isn't violating any rules,

My plan is to rebuild the pack in a 17 or 18 S and 10 p config - approx 58 or 62 volt and 20 amp/hr

Questions:
Will 62 volts be too much voltage Voliomart tells me 32 to 60 volt range.
Will a 20 amp/hr with the beefier battery controller help with my hill climbing?
Should I add more in Parallel? ie 22/24/26 amp hr etc?
My charger is maxed out at 61 v, is this gonna be a problem is I go with 18s (again 3.2v lifepo4 cells)
Don't care about going faster 35 mph on a mountain bike is fast enough for me, I more concerned about getting up the hills. fwiw I weigh 200. bike is about 40. road slope is about 40 at times

Thanks

More links the better. A link to the batteries you referred to would be helpful.
Motors aren’t rated for voltage; they are rated for power. They only list a voltage to support other stuff in the description (e.g. they may say 48v and also say 30mph with. 26in wheel). The only issue is that if you go above 72v, the cost of controllers go way up.
If you mean by 20 amp/hr you mean 20Ah, then that’s a capacity value (how many amp hours are stored in the fully charged pack), and not the discharge rating (which would just be in amps). The rating discharge amps are what you need to know. More parallel cells increases both Ah and rated discharge amps. More amps results in greater torque and more volts also results in more torque since it raises the torque curve across the rpm range.
Depending on your motor (i.e. direct drive vs geared), you may want to add coolent/Statorade, since you will have more heat as power goes up. A temp sensor would be good insurance as well.
Power-wise, you can run quite a bit of power as long as you keep an eye on motor temp. I have. 1500w direct drive motor and run over 7kW peaks. With Statorade and keeping speed at about 20mph (around 4300w), I can climb any hills in my area without overheating. My test hill is an 800 foot climb, and 20% for the last third of a mile, and I just hit 100C at the top (riding faster increase heat). If I climb at above 30mph, heat goes up really fast and will be pulling 7kW on the steep section.

1 mile test run:

Edit: I forgot to mention, there is a definite downside to going with higher voltages; your throttle will become more difficult to control. If you go above 72, you may get thrown on your back, even if you’re expecting it.

 

[hillslayer@]

More links the better. A link to the batteries you referred to would be helpful.
Motors aren’t rated for voltage; they are rated for power. They only list a voltage to support other stuff in the description (e.g. they may say 48v and also say 30mph with. 26in wheel). The only issue is that if you go above 72v, the cost of controllers go way up.
If you mean by 20 amp/hr you mean 20Ah, then that’s a capacity value (how many amp hours are stored in the fully charged pack), and not the discharge rating (which would just be in amps). The rating discharge amps are what you need to know. More parallel cells increases both Ah and rated discharge amps. More amps results in greater torque and more volts also results in more torque since it raises the torque curve across the rpm range.
Depending on your motor (i.e. direct drive vs geared), you may want to add coolent/Statorade, since you will have more heat as power goes up. A temp sensor would be good insurance as well.
Power-wise, you can run quite a bit of power as long as you keep an eye on motor temp. I have. 1500w direct drive motor and run over 7kW peaks. With Statorade and keeping speed at about 20mph (around 4300w), I can climb any hills in my area without overheating. My test hill is an 800 foot climb, and 20% for the last third of a mile, and I just hit 100C at the top (riding faster increase heat). If I climb at above 30mph, heat goes up really fast and will be pulling 7kW on the steep section.

1 mile test run:

I could do that hill at 20 mph on 48 volts and less than 3000 watts and motors would only be warm.

 

[E-HP]

I could do that hill at 20 mph on 48 volts and less than 3000 watts and motors would only be warm.

That’s great if that’s what you want to do (I didn’t realize you lived by me). I'm just trying to help the OP since he has a direct drive so it’s relevant to his question and equipment choice he’s already made. I’m usually on a mix of flats and the curves and rolling hills where it’s fun, but I do like testing and data, and comparing against the Grin simulator. I have another route for testing voltage sag, and another for 0 to 40 runs. I used the same hill for regen testing (part of temperature testing), I can do the whole steep section at 30 or more, but my testing route is the full mile to have a set mix of gradients (as well as low traffic).
Is your bike silent? I don’t care much about power, as long as I have enough, and it’s basically free, but I do care about noise, which eliminates mid drives. I may build one at some point for single track riding though.

 

[hillslayer@]

BBSHD and BBSO2 are almost silent and my hub is direct drive . Adding a mid-drive to a hub may actually cost less than upgrading controller and battery. I have climbed 20% in my own area . I am just saying if you have a lot of hills a hub by itself might not be the best option.

 

[Chalo]

I could do that hill at 20 mph on 48 volts and less than 3000 watts and motors would only be warm.

3000W through bike gears never ends well. I had enough breakdowns and maintenance overhead on 1200W with my BBS02 that I decided hub motors were for riding and mid drives were for repairing. I already spend my days repairing bikes for a living, so I switched to hubs and I'm very happy with the change.

 

[E-HP]

I can’t avoid hills since I live on one. The majority of routes I take here are 15% or less so there’s no real heat issues unless I’m hotrodding around and not paying attention. Im finally getting ready to add my low profile heat sinks to see if they help, so more testing to come . But ya, the BBSHD is the only mid drive I’d consider, for single track riding, because the ones I’ve seen are fairly quiet. For anything else, I’m too lazy to shift or deal with the maintenance.
I think my hill climbing test route is almost ideal. A sustained 800 ft uninterrupted climb, little traffic, and fairly straight. Routes like these are rare. Boring for normal riding though.

I had a couple of times when BBSHDs seemingly were trying to race me, and just goated them by letting them stay close, but both times they almost comically gave up when getting to a steep hill. As soon as they’d downshift, I’d throttle, so 30 seconds later when I’m 3 or 4 blocks ahead, they’d just give up. If they kept going, they might have been able to catch up, but psychologically they were already broken. I know how it feels though. I remember driving over the grapevine in a little Toyota once and had to downshift at one point and move to the truckers lane; that sucked and was sort of embarrassing.

 

[hillslayer@]

Combining a mid-drive with a hub is what I did. You might be a little faster but with a lot more waste heat being generated.