Setting Up Supermate DC6

First off, you should leave the module in the battery carrier frame -- the four rods and two plastic ends. Have everything tight, just take off the bus bars. The modules are structurally designed to press against each other and the two white pieces of hard plastic at the ends. A C clamp which two pieces of works okay but may crush raised portions of the module exterior.
A module will begin to swell/heat up at 80% SoC under charge. You should also have a fan running to keep them cool.

I set a charge cutoff of 7500 mAh, a discharge cutoff of 6V. For best results, do discharge -> charge first. That is also informative of the overall battery condition. Be sure to record the initial discharge numbers. When the charger is done, you can page through with the arrow keys. Initial discharge the most valuable piece of information. If they are all about the same on initial discharge, then it is likely a good rebuildable battery. If there are significant differences between multiple modules, then it is a virtual guarantee that the ones with much lower initial discharge have been worn out.

 

Fully charged voltage is >9V. Since these tend to heat up and swell, the -dV/dt peak can be difficult for the charger to detect and the module can be overcharged. If you discharge first and go only 7500 mAh, you can be assured that a good cell will not be overcharged. Due to Peukert's, it takes more than 6500 mAh to fully charge a good module. If every module accepts 7500 mAh on the final charge, that is a very good sign, because that means that the modules will be closely balanced. If you have a case of some accept 7500 mAh while other stop at 6500 mAh, that is a bad sign, because there will be a state of charge and/or capacity mismatch between those modules if they are paired in the same block.

 

One thing I should have asked, you have a dual channel charger? Because these things heat up, I never charge adjacent modules at the same time, I always charge every-other-one. That could contribute to a lower than expected discharge reading.

Or, it is just an indication of battery wear. 6000+ mAh in generally accepted as being good enough.

 

Don't mean to hijack this thread but I'm going to be rebalancing my battery soon. It seems to heat up very quickly and charge quicker than it used to. I have some questions:

1. Can I remove everything inside the car to access the battery and then leave it in there to do the rebalancing?

2. Are the bus bars the only thing that needs to be removed to rebalance the modules?

3. There is a DC6 Supermate charger for sale locally but the guy used it to charge his remote control cars. I assume this is the one I want (or are there different types of DC6 chargers?) and that there isn't a difference between the remote control car batteries and the Prius batteries, other than battery capacity?

4. How long can I expect the rebalancing to take if I have one charger?

5. I'm an electronics technician and work with up to 1800 VDC at work. I'm comfortable with working on the Prius battery but I've never done it before so my concerns lie in the procedure. In its simplest form, this is just discharging and re-charging each module 3-4 times, correct?

6. Do you just set the parameters you want on the DC6 and then just repeat the same process X amount of times?

 

your amswers............
1-yes
2-yes
3-the type of chemistry that it is programmed for. Prius batt are NiMH. Usually rem control batt are LIPO
4- depending on the state of each module, but an average of 2hs per .
5-yes and not. discharge/charge no more than twice per .
6-yes

 

Great, thanks. Some additional questions:

1.

I've read on here that 3-4 times is what people use. Why do you only limit it to two discharge/charge cycles?

2. This is the charger I was looking at: Dynam Supermate DC6 DC Multi Function Balance Charger/Discharger 1-6 cell Lilo/LiPo/LiFe, 1 to 15 cells NiCd NiMH It says it's for NiMH. Should be good, right?

3. Should anything be cleaned while I have the battery open?

4. Not sure why I'm asking this, maybe it's just curiosity. Do you have to rebalance all of the modules at once or can you rebalance a few, use the car and then rebalance the rest a week later?

 

1 - after the second time you will start seeing charging differences, besides you will have to measure voltages "at rest" and that will take you some time.

2 - NiMH algorithms is what you need. Also, you will need an external power supply for this type of products. I own and used a similar device for my needs 6 years ago on a "One time investment".

3 - I do not know the battery age, but by experience, after 4 years of new, you will notice some sulfatation on the battery links and this will be a problem. Depending in your local weather conditions, I leave near the ocean.
For the battery terminals I use a bronze (could be a steel )wire brush to clean-up the threaded surfaces. The size of a tooth brush.
For the links, I run them on a bench grinder with a wire brush 'till copper shiny. Then I learned that these will tarnish again, so after the first process I "thin" them in a chemical solution (thin plating) for a couple of minutes. Check ebay suppliers for this. This processed links last me for 3 years already with out a problem and a perfect electrical transfer.
But this is just me.

4 - I never rebalanced the additional 4 packs that I have again, because I dis carted the bad modules or the ones showing a noticeable difference. Then everything will top and lower balance withing its own range.

 

I've seen people on here say that when you rebalance an individual module you should keep the modules together inside the case. What should I do if I have three modules that I want to rebalance? Should I put them in a vise between two blocks of wood or is it not that critical?

 

First I would take the easy step and re-balance in withing the pack, with everything compacted.
If you find that you have suspected modules not recovering from the process, I would replace them. And yes, for this operation you will have to split the pack.
I found that almost always, you will have a pair of adjacent modules with low readings.

 

.....and yes, always you will have to compress a module to avoid bulging as you previously stated.

 

My dilemma is the legnth of time to complete the process. I was reading a post where it takes 1.5 days for the DC6 charger to complete the rebalance process in 1.5 days. Is that an accurate statement? That seems really long to me.

What I was trying to do was prepare a few cells ahead of time and in the event I find a bad module I could just put it in and save some time.

 

I was never able to do more than 2 modules a day (my way), now if you take the 5 times approach.......it will be very time consuming

 

If I understand you correctly, the reason why it takes so long is because the cycles each person uses. One cycle obviously takes a shorter amount of time than three cycles.

How long does one charge/discharge cycle take? How long do you program your time to "rest" between each charge/discharge cycle? I'm guessing all of that adds up and that's why it takes so long.

 

the amount of time is different from module to module but lets said a nominal OK module will take about 85 to 95 minutes full cycle. My charger is different brand but similar to yours but "not identical" at 4.5Amps.
I used to let the modules rest for a day at room temp and compressed.

 

I really do not remember now, it was a few years back.; but I estimate it was approx 7 to 10 minutes between cycles.

 

old thread but have a question - what is the best way to power up the Dynam Supermate?