60 volts through a 48 volt brushless DC controller

7

70oldsracer

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I'm new to this forum and I just put together a Razor MX 500 for my son. It now has a 48 volts, with a 48 volt Brushless DC controller and a 48 volt brushless DC motor. The bike works great, but I was wondering if I would hurt anything by trying to run it on 60 volts. Right now I'm using four 12volt 12ah batteries and I just want to add another to the pack. Any help would be greatly appreciated.
https://www.amazon.com/Mophorn-Electric-Brushless-Controller-Motorcycle/dp/B07KF8M5W6?pf_rd_p=0fc3f2c4-3ed5-4d11-9995-8d7c82394713&pd_rd_wg=y0LG0&pf_rd_r=G20B0S5F2W6F9MASWWWF&ref_=pd_gw_cr_simh&pd_rd_w=zJ6Qo&pd_rd_r=917619e8-4065-4269-acab-9a8745b1244e This is the set up I'm using.
 
It depends what guts are inside your controller. One way to get a clue it's a see if you have 63 volt Caps or 75 volt caps. I guess these our lead battery's ? If 63v caps No.
 
Welcome to the forum

Fast answer, No. But you can add a 6 volt...

Most of those controllers contain parts that can handle up to 63 volts measured max, and can blow up at 63.1 volts.
Fully charged batteries have more voltage at peak charge than what they are listed for. For example, A 12 volt lead acid battery can have 13.5 volts fully charged. So 5 of those used to make a 60 volt battery would have a max voltage of 67.5 volts. That would fry your controller probably instantly.

However, I have run four 12 volt and one 6 volt SLA batteries on one of those 48v controllers. It made a 54 volt battery with a peak of 60.75 volts. So a 6v 12Ah battery of the same type will very likely be fine.

If you're running Lithium, 14S (14 lithium cells in series) is generally safe at a peak of 58.8v. 15s is possible as it peaks out at 63v, but it's risky. not every controller survives, but most do.
 
Yes, SLA batteries. I was thinking about adding a 5000mah 11.1 volt battery to my 48 volt sla battery pack. Just as a boost, it would be wired to a separate momentary on switch.
https://www.ebay.com/itm/Traxxas-TRA2872X-LiPo-Battery-25C-11-1V-Volt-3S-Cell-5000mAh-TRA-ID-Plug-1-10/293021739135?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908131621%26meid%3Dab183b3fcfc240c69cb59f739d57ec3b%26pid%3D100678%26rk%3D6%26rkt%3D15%26sd%3D192879156799%26itm%3D293021739135%26pg%3D2481888&_trksid=p2481888.c100678.m3607&_trkparms=pageci%3Ad587454c-ae66-11e9-8e46-74dbd1806204%7Cparentrq%3A2636efec16c0aa67f0938e94ffe0b91d%7Ciid%3A1
I guess I should just buy a 60 volt controller. Any suggestions on a good controller? I was looking at this one
https://cart.electricscooterparts.com/productdetails_popup.asp?productcode=SPD%2D602000BLDC
 
70oldsracer said:
Yes, SLA batteries. I was thinking about adding a 5000mah 11.1 volt battery to my 48 volt sla battery pack. Just as a boost, it would be wired to a separate momentary on switch.
https://www.ebay.com/itm/Traxxas-TRA2872X-LiPo-Battery-25C-11-1V-Volt-3S-Cell-5000mAh-TRA-ID-Plug-1-10/293021739135?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908131621%26meid%3Dab183b3fcfc240c69cb59f739d57ec3b%26pid%3D100678%26rk%3D6%26rkt%3D15%26sd%3D192879156799%26itm%3D293021739135%26pg%3D2481888&_trksid=p2481888.c100678.m3607&_trkparms=pageci%3Ad587454c-ae66-11e9-8e46-74dbd1806204%7Cparentrq%3A2636efec16c0aa67f0938e94ffe0b91d%7Ciid%3A1
I guess I should just buy a 60 volt controller. Any suggestions on a good controller? I was looking at this one
https://cart.electricscooterparts.com/productdetails_popup.asp?productcode=SPD%2D602000BLDC
Click to expand...

The low voltage cutoff of the controller you linked is 53 volts. If you do what you're proposing, the controller will cutout when you switch to only the 48 volt battery if it's anything below fully charged.
 
That's what I originally wanted to do with the 48 volt controller, but I see that it's not possible. If I go with the 60 volt controller, I'll be running a 60 volt battery pack. Anyone know of any other 60 volt controllers they can recommend?
 
https://www.ebay.com/itm/DC-48-72V-1800W-E-bike-Scooter-Brushless-Motor-Electric-Bicycle-Speed-Controller/173951532280
If I go with a controller like this, I can still do the 11.1 volt lipo battery on a momentary on/off switch. Anyone know if this controller is any good? or do you know of a 48-72V 1800 Watt controller that is good?
 
70oldsracer said:
https://www.ebay.com/itm/DC-48-72V-1800W-E-bike-Scooter-Brushless-Motor-Electric-Bicycle-Speed-Controller/173951532280
If I go with a controller like this, I can still do the 11.1 volt lipo battery on a momentary on/off switch. Anyone know if this controller is any good? or do you know of a 48-72V 1800 Watt controller that is good?
Click to expand...

Just to be clear, are you asking based on your original plan, or now talking about 60v and 71.1v (60 + 11.1) when using the button?
You can't tell by the description if then LVC can be set manually, or if the controller auto-senses what it thinks the voltage is, and sets it based on that; or if there is an LVC at all.
 
Sorry, original plan of 48 volts plus 11.1 for a total of 59.1 volts with the button pressed.
 
70oldsracer said:
Sorry, original plan of 48 volts plus 11.1 for a total of 59.1 volts with the button pressed.
Click to expand...

There's a decent chance that it will work, but without better specs or description on the controller, you can be certain. I'm going through a similar exercise, but without the button. I want to be able to use my 52v pack, and also run at 60v or 72v by adding other packs in series, so I've been researching the controller options. I'm looking for other features as well, so the search goes on.
 
70oldsracer said:
I was thinking about adding a 5000mah 11.1 volt battery to my 48 volt sla battery pack. Just as a boost, it would be wired to a separate momentary on switch.
Click to expand...
That's going to have to be a heck of a switch, since it has to carry the full current of the system, and it also has to handle the arcing of switching while loaded. Under load, the startup and switching currents can be 30-50A or more (even if the controller's current limit is much lower), and the arcing can be pretty severe (damaging the switch contacts, potentially welding them together in one position or the other--or worse, welding just one contact set, and letting the other still switch, potentially making a short across a battery and causing a fire, depending on how it's wired).

It's probably going to be half the size of the battery you're adding, and it's likely to cost more than the battery.

It's possible a smaller switch will work fine for a while, but the consequences of failure have the potential to be severe.

It needs to be a break-before-make DPDT switch, at least, so you can disconnect the main positive of the system from the most positive battery's positive terminal, then connect that terminal to the negative terminal of the new battery, and the positive terminal of the new battery to the main positive of the system.

I'd venture it's probably cheaper and easier to replace the controller with a higher voltage unit, and wire the third battery permanently in series with it instead.
 
70oldsracer said:
Sorry, original plan of 48 volts plus 11.1 for a total of 59.1 volts with the button pressed.
Click to expand...

First problem. You can't add a battery to a circuit without disconnecting the circuit first. as soon as the circuit is opened, the brushless controller shuts down and has to reboot.
You can switch voltages with the push of a button, but you'll have to stop to do it.

70oldsracer said:
https://www.ebay.com/itm/DC-48-72V-1800W-E-bike-Scooter-Brushless-Motor-Electric-Bicycle-Speed-Controller/173951532280
If I go with a controller like this, I can still do the 11.1 volt lipo battery on a momentary on/off switch. Anyone know if this controller is any good? or do you know of a 48-72V 1800 Watt controller that is good?
Click to expand...

the 48-72 part is what you're looking for, so probably one like that. But again, no. you can't add the Lipo battery with a momentary switch. You might be better off skipping the Lipo and just adding a 5, and maybe a 6th SLA, that 72 volt controller can take it. Or go all lipo.
 
Drunkskunk said:
70oldsracer said:
Sorry, original plan of 48 volts plus 11.1 for a total of 59.1 volts with the button pressed.
Click to expand...

First problem. You can't add a battery to a circuit without disconnecting the circuit first. as soon as the circuit is opened, the brushless controller shuts down and has to reboot.
You can switch voltages with the push of a button, but you'll have to stop to do it.

70oldsracer said:
https://www.ebay.com/itm/DC-48-72V-1800W-E-bike-Scooter-Brushless-Motor-Electric-Bicycle-Speed-Controller/173951532280
If I go with a controller like this, I can still do the 11.1 volt lipo battery on a momentary on/off switch. Anyone know if this controller is any good? or do you know of a 48-72V 1800 Watt controller that is good?
Click to expand...

the 48-72 part is what you're looking for, so probably one like that. But again, no. you can't add the Lipo battery with a momentary switch. You might be better off skipping the Lipo and just adding a 5, and maybe a 6th SLA, that 72 volt controller can take it. Or go all lipo.
Click to expand...
Okay, can I run four 12 volt batteries and one lipo 11.1 volt battery for a total of 59 volts of constant power, no switch? The lipo is smaller than the 12 volt sla battery and easier to make room for. I'll charge the four 12 volt sla batteries together and the lipo battery separately.
 
Yes, on the 72 volt controller. 4SLA + one 11.1v Lipo is 66.6volts when full charge.

There is a danger of destroying the lipo that way, as the lipo may drop it's voltage below it's destruction point before the SLA lose much voltage. So be aware of the Lipo's voltage limits.
But yeah, it will work.
 
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