Asked — Edited
Resolved Resolved by Dunning-Kruger!

Sabertooth 2X25 With Dual 12V Batteries

I've got a Jet2 wheelchair base. The two motors require two 12V batteries. All of the wiring diagrams for the Sabertooth 2x25 that I've seen so far just show 1 battery. I of course have 2. Am I supposed to be wiring my two batteries in series? Or in parallel? or do I just connect both battery reds to Sabertooth B+ and both blacks to Sabertooth B-?

I've read the whole Sabertooth 2x25 manual and all the Jet2 manual & materials I can find. I've already disconnected and removed the brakes in my motors. I know I'm not the first person to use a Jet2 with a Sabertooth 2x25. I must be Googling the wrong words. Help? Links?

Thanks!


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#1  

parallel if they are 12V motors... series if they are 24V motors

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#2  

@rryerson Thanks! The Jet2 seems to have 24V motors, so series it is. Testing the batteries in series gave 22.9v on the multimeter. Both motors ran forward and backwards when 24v was applied. :D

Earlier I somehow smoked my Sabertooth 2x25. Not sure how I did that as I was very careful with black vs red. Sigh...

#3  

Can the sabertooth handle 24v? Also are you sure both batteries are fully charged... you should see over 24v when in series on your multimeter.

#4  

I sprung for the Sabertooth 2x60 now. Happy birthday to me! No more messing around with the 2x25...I'm not convinced I wired anything wrong to kill it. I definitely never reversed black/red. Technically I should be ok with 24v on the 2x25 but I've heard of others with issues with 2x25 and Jet2 power wheelchair.

The batteries are not recently charged so 22.9 is reasonable I suppose.

#5  

I would charge those batteries as soon as possible if I were you... And also make sure you check your wiring before hooking up your new sabeetooth.... I googled the sabertooth controllers... they should be good up 36v...

#6  

Just a suggestion... You may want to put the batteries in parallel and test it at 12V to see if it is fast enough. Those scooters hum right along. With a light weight robot you might find that full speed is dangerously fast. If 12V isn't enough, you can easily switch it up to 24V.

#7  

The Sabertooth 2x60 is soooooo niiiiice! Worth every extra penny! Hooked it up to my EZ-B and I'm good to go! She works like a charm! FINALLY I can move on!

@Danger, yes I agree that 12V seems to be more than enough so I am wiring the batteries in parallel for now. If the load (snow plow) proves too much then I'll switch to series.

Thanks y'all!

#9  

I am glad to hear that it is working as well. I have the same motors, and the same Sabertooth for my B9. I have not gotten to the point of putting them in it yet.

#10  

I was wondering if any body has tried using the same remote and receiver back and forth on 2 different robots, my lawn mower has a 2x25 saber and my new bot has 2x60 tried to bind to new bot but the light is green but motors will not turn, and I don't know if fan turns all the time because mine don't applied power but fan spins for 3 seconds then shuts down but green light steel on, any ideas 24v system I was wondering if the receiver needs its own power source any ideas any body? And what size of wire recommend using on power leads I'm using 10g, and 12g on motors?

#11  

You will get a better answer by posting this question in a new request for support.

Unknown Country
#12  

Evidently the sabertooth must use batteries in parallel. Not series. I just fried my 2x32, so now you know lol. The reason in the regenerative properties can't recharge the batteries, then it basically overloads itself in smoke sparks and fire and $200 bucks later ...User-inserted image

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#13  

Ouch - that's an expensive lesson! How many volts were your batteries outputting in series? I think the max voltage is around 24v or something. But it should be rated in watts because 24v at 50amps would not be pleasant!

Unknown Country
#14  

I was actually using  a 2x32, it can handle 36v and peak amps are about 60. I used a bench power suppy with the same 24v 22a setup with no problems,  but the lead acid series had different 'evil' plans lol. (Yes changed dip switch to match battery power ant set everything up in DEScribe)

#15   — Edited

It should have been able to handle the 24 v and 22amps no prob. There may have been something else that made it it go poof. It's definitely a tricky animal. I read your comment a little closer and thanks for the info about sabertooth handling series or parallel-makes sense.

#16   — Edited

I had one blow-up on me last year, after investigation, it was related to the Ground reference for the signal wire. Are your saber tooth and EZB powered from the same source? If so how do you have it wired?

Series or Parallel does not matter for batteries, but Dimension recommends an 18Ah minimum for the regenerative system on a 2x25. I imagine this is the factor that determines what you should do regarding your battery setup.

#17  

Personally I've done them both ways series and parallel and I don't get involved in regenerative scenario so that takes it out of the equation. I tap off a 18v drill battery for both the sabertooth and a transformer down to 7.5v for the EZB. Need to make sure you have a common ground.

#18  

Quote:

I don't get involved in regenerative scenario so that takes it out of the equation.
I don't understand this statment. Can you expound? As far as I know you can't shut off the Sabertooth regen process. it happens whenever you command your robot to slow down or reverse. The generated voltage is back fed into your battery to recharge it. The only way to stop it is to use a voltage clamp. They offer a 2x32 model that had a voltage clamp built in.

#20   — Edited

Well, yes. Kinda. There different ways to use the 2x32's and to handle the regen power of all the Sabertooth motor controllers. Every ST puts out regen power that has to be dealt with properly. There is no option to turn off the regen power on any of the ST's. Also, you can't just put in a diode and block it. You run the chance of burning up the diodes and/or the Sabertooth if you do. The power has got to go somewhere. If you are running off of a power converter and not using a 2x32 you need to have a dump battery between the PS and the ST to have a place for the Regen power to go to. If you are using a 2x32 you need to have it set to the voltage clamp option (this is the factory setting) and have the proper value power resistor installed on the unit. The Power resistor adsorbs the regen power and spends it as heat.

If you are already powering your ST from a battery this is all moot. That is probably why you don't have to deal with it. Your regen power is naturally being sent back to your battery power source and keeping it recharged (to a point).

I love this stuff! It's science and so much fun! LOL.

#21  

Yes, I have been running it with a battery, but I also have been putting a power supply in parallel with it because somewhere in the software manual I happen to see that and everything seems to be working out fine. Haven’t had any problem with it blowing.

#22  

Dave, I think you'd get a kick out of the automation shows that I go to. Next time one is in Orlando I'll let you know and see if you're interested. It's called ATX South or East. Take care

#23   — Edited

Quote:

Dave, I think you'd get a kick out of the automation shows that I go to. Next time one is in Orlando I'll let you know and see if you're interested. It's called ATX South or East. Take care
Thanks! I'd love that. Orlando is about a 3.5 hour drive north for me as I'm in lower SW Florida but nothing wrong with a little road trip.