Now you got me thinking.
How did you monitor the charge of the batteries? With a Voltage gauge and if so you should have seen the voltage drop off as soon as the charger shut down if the batteries weren't fully charged. How many steps is this "charger" you have on board? Is it temperature compensated? I'm also interested if the PowerCheq had anything to do with this but I can't see how unless you had a bad battery.
Steve
Made a Mars motor installation from Thunderstruck. Added 4 12V 120Ah semitraction lead acid atteries. Mounted PowerCheq equalizers between them. Charging with a 20A 48V automatic charger from Kipoint, Taiwan. Experienced very short sailing distance first year (08). Added much bigger heatsink and a fan on the controller, which apparently got too hot. 09 experienced still very short sailing distance (less than one hour at half speed, 3 knots). When one shore last autumn I found out that the batteries were not at all properly charged (controled with an acid float tester). When charging, the voltage raised in short time to about 59V, whereafter the charger switched off as it should. But the batteries were not charged. Home in the workshop I could charge the batteries invidually with a small automobile charger (long time), and all 4 batteries came up to full charge.
What goes wrong in the boat? Is the charger too big (20A). Have the batteries too big internal resistance, sonce the voltage came up, but the charging did not?
Any advice shall be very appreciated. Byt the way: one of the PowerCheq's had blown its fuses and were shorted internally.
Best regards, David from Denmark
------------
Yahoo! Groups Links
Thursday, April 29, 2010
RE: [Electric Boats] troubles charging batteries
RE: [Electric Boats] troubles charging batteries
David,
Were you able to evaluate the PowerCheq at all? What was your impressions and do you think it did any good?
Thanks,
Steve
[Electric Boats] Re: Controller for 300w and microprocessor
Wow! Sounds like a neat project. The parallax propeller by itself looks like a neat uC. I haven't gotten around to playing with one yet. How do you like spin?
You have probably done this but have you contacted the controller manufacturers directly and asked for the protocol (if available)? You might get it with an NDA. I haven't personally seen a controller like the one you're asking about, but I haven't looked for one either.
Do you have a web page for your project? I'd like to know more.
Regards,
James
--- In electricboats@
>
> Ok, I wasn't clear and I paid for it ! So let me explain a bit more.
>
> The parallax propeller chip is managing the 17ft boat. We currently monitor environmental things like water temp, water speed, ground speed and GPS position. The goal was to expand that when we replace our ICE with electric. The project grows in software first, then in hardware.
>
> With some help from the propeller forum, we are about to install monitor circuits that will monitor the 4 individual batteries including charging, and their overall health/capacity (battery temp etc). We can monitor the small windmill that charges the boat when docked as well as the twin chargers. Xbee will send data to the house computer for display.
>
> We would like to be able to tie this same system to the speed control for the boat. Then I can look at consumption vs supply and we can do some experiments. I can of course connect a servo to a pot and have speed control. Thats kind of a no-brainer and probably where I will end up but....
>
> Many of the AXE controllers support a serial interface which I suspect could give me a lot of useful information about the motor, the consumption at the head, losses etc. Even the temp of the controller itself might be worth looking at. But sadly, the AXE controllers use a proprietary format to talk to the Windows based PC. And I am certainly too lazy to reverse engineer that. And it looks like I can read it from the PC, but not control it.
>
> We have not purchased the motor because for us, the controller will make the motor decision (brushless et al). My goal is not to run the motor through the prop chip. That I do in RC/robot land all the time but this is a whole different scale when we start in the 4-8hp range. The prop chip will provide an input signal and I've got a wealth of approaches to provide data to the controller from serial to midi to ethernet and almost everything in between.
>
> Ideally, I would like a speed controller that I could set speed directly from the micro and read data back through serial or other 'open' connection. To the original specs, 48V / 400W. Dual motor control would be preferred.
>
> If all I can do is the servo-pot connection, it's not fatal. Just lost opportunity for me. And yes, we will probably add automatic steering next year when we build the new boat. But I think this is enough on our plate for the summer.
>
> Thanks
>
>
>
> --- In electricboats@
> >
> >
> > The Arduino (about $30) does PWM as a standard part of its architecture. The question seems to be fitting MOSFETS (or whatever) on the motor controller side.
> >
> >
> >
> >
> >
> >
> >
> >
> > -----Original Message-----
> > From: hardy71uk <p0054107@>
> > To: electricboats@
> > Sent: Thu, Apr 29, 2010 4:51 am
> > Subject: [Electric Boats] Re: Controller for 300w and microprocessor
> >
> >
> >
> >
> >
> > The simple way to do it is with a voltage controlled controller . then the interface can be a very basic digital to analog convertor circuit. the somewhat more technical way is to generate pulse width modulation in the micro.
> >
> > Chris S
> >
> > --- In electricboats@
> > >
> > > I've been digging through the various controller circuits and while I am finding more than a few excellent controllers, I am not finding one that can be controlled by a microprocessor.
> > >
> > > Anyone know of a good one ? I've got everything running on my test setup so I don't have the real motor yet either, but I need the controller to get the software written. I need somewhere around 48V / 300-400W.
> > >
> > > I thought I saw one that could control 2 motors but that may have been in a parallel universe.
> > >
> > > Thank you all
> > >
> >
>
[Electric Boats] Re: Controller for 300w and microprocessor
It sounds like you'll be wanting a Brushed DC motor (for simplicity). You should read up on H Bridges (allows forward, reverse and brake) and PWM control. A stamp, Pic, or AVR would fit the bill nicely (I like AVR).
You can get as complicated as you like. Add a magnet and hall effect sensor, and PID control becomes possible. Sense resistors on the input rails and you can report back current usage. You'll probably want to just stick with simple PWM control, and read a potentiometer off of an A/D on the chip for speed input.
Others have pointed out arduino, which is fine too (never used it myself but it looks interesting)
You're unlikely to find an integrated H-Bridge on an IC at the current required for the motors used here. You'll likely need to design your own. It can be done with simple relays but I wouldn't recommend it. Mosfets are a better solution IMHO, but watch the internal resistance closely (RDSon [HEAT]), and pay attention to back EMF.
There are some open source projects out there (openservo comes to mind) that you can look at as a guide. All of the projects I've seen seem to be geared toward much lower current (not that 10amps is that bad).
I don't think you'll find just the "controller" portion by itself. Why go to all of the trouble of putting the hardware together, and not slap a uC on it?
Dual control could be possible. Two H bridges and two PWM lines. You will want PID control, since if you get them out of sync speed wise, your boat would turn. The reprap project has a neat 1024 bit magnetic encoder (open source), that might be useful here.
sparkfun, pololu, and avrfreaks are probably better places to get ideas.
I hope this helps.
James
--- In electricboats@
>
> No doubt, but since I don't have the motor, if you can point me at one that does allow a basicstamp to talk to it (or any other micro) then I can always buy the motor that matches.
>
> Thanks
>
> --- In electricboats@
> >
> > What kind of motor? Brushed, Brushless DC, AC Induction? It makes a big difference.
> >
> > Regards,
> >
> > James
> >
> > --- In electricboats@
> > >
> > > I've been digging through the various controller circuits and while I am finding more than a few excellent controllers, I am not finding one that can be controlled by a microprocessor.
> > >
> > > Anyone know of a good one ? I've got everything running on my test setup so I don't have the real motor yet either, but I need the controller to get the software written. I need somewhere around 48V / 300-400W.
> > >
> > > I thought I saw one that could control 2 motors but that may have been in a parallel universe.
> > >
> > > Thank you all
> > >
> >
>
[Electric Boats] Re: Controller for 300w and microprocessor
Pot throttles are very energy inefficient.
--- In electricboats@
>
> Why the microprocessor rather than one of the more common potentiometer throttles? And are you really only expecting maximum current loads of less than 10A? Is this for a boat?
>
> Eric
> Marina del Rey, CA
>
> --- In electricboats@
> >
> > I've been digging through the various controller circuits and while I am finding more than a few excellent controllers, I am not finding one that can be controlled by a microprocessor.
> >
> > Anyone know of a good one ? I've got everything running on my test setup so I don't have the real motor yet either, but I need the controller to get the software written. I need somewhere around 48V / 300-400W.
> >
> > I thought I saw one that could control 2 motors but that may have been in a parallel universe.
> >
> > Thank you all
> >
>
[Electric Boats] Re: Controller for 300w and microprocessor
Ok, I wasn't clear and I paid for it ! So let me explain a bit more.
The parallax propeller chip is managing the 17ft boat. We currently monitor environmental things like water temp, water speed, ground speed and GPS position. The goal was to expand that when we replace our ICE with electric. The project grows in software first, then in hardware.
With some help from the propeller forum, we are about to install monitor circuits that will monitor the 4 individual batteries including charging, and their overall health/capacity (battery temp etc). We can monitor the small windmill that charges the boat when docked as well as the twin chargers. Xbee will send data to the house computer for display.
We would like to be able to tie this same system to the speed control for the boat. Then I can look at consumption vs supply and we can do some experiments. I can of course connect a servo to a pot and have speed control. Thats kind of a no-brainer and probably where I will end up but....
Many of the AXE controllers support a serial interface which I suspect could give me a lot of useful information about the motor, the consumption at the head, losses etc. Even the temp of the controller itself might be worth looking at. But sadly, the AXE controllers use a proprietary format to talk to the Windows based PC. And I am certainly too lazy to reverse engineer that. And it looks like I can read it from the PC, but not control it.
We have not purchased the motor because for us, the controller will make the motor decision (brushless et al). My goal is not to run the motor through the prop chip. That I do in RC/robot land all the time but this is a whole different scale when we start in the 4-8hp range. The prop chip will provide an input signal and I've got a wealth of approaches to provide data to the controller from serial to midi to ethernet and almost everything in between.
Ideally, I would like a speed controller that I could set speed directly from the micro and read data back through serial or other 'open' connection. To the original specs, 48V / 400W. Dual motor control would be preferred.
If all I can do is the servo-pot connection, it's not fatal. Just lost opportunity for me. And yes, we will probably add automatic steering next year when we build the new boat. But I think this is enough on our plate for the summer.
Thanks
--- In electricboats@
>
>
> The Arduino (about $30) does PWM as a standard part of its architecture. The question seems to be fitting MOSFETS (or whatever) on the motor controller side.
>
>
>
>
>
>
>
>
> -----Original Message-----
> From: hardy71uk <p0054107@..
> To: electricboats@
> Sent: Thu, Apr 29, 2010 4:51 am
> Subject: [Electric Boats] Re: Controller for 300w and microprocessor
>
>
>
>
>
> The simple way to do it is with a voltage controlled controller . then the interface can be a very basic digital to analog convertor circuit. the somewhat more technical way is to generate pulse width modulation in the micro.
>
> Chris S
>
> --- In electricboats@
> >
> > I've been digging through the various controller circuits and while I am finding more than a few excellent controllers, I am not finding one that can be controlled by a microprocessor.
> >
> > Anyone know of a good one ? I've got everything running on my test setup so I don't have the real motor yet either, but I need the controller to get the software written. I need somewhere around 48V / 300-400W.
> >
> > I thought I saw one that could control 2 motors but that may have been in a parallel universe.
> >
> > Thank you all
> >
>
[Electric Boats] Re: Salt water corrosive effects on Mars motor ?
I have the brushless and am at about 2.5 years (Hans and I are neighbors). I recently sprayed the _inside_ of the motor with conformal compound (I don't think you can do this with a brushed..) - I am seeing some pitting on the casing, and I had one controller failure that I attribute to corrosion induced by a poor dielectric and insufficient torque on one of the motor wires.
-Keith
--- In electricboats@
>
> Can anyone share experience with the Mars brushed or brushless motor, and how it has lasted.... or not ... when installed in an ocean salt water rig ?
>