battery module seller

TMR-JWAP

The PM (start a conversation) function hasn't been working correctly for months.
If you click on TMR-JWAP user name, it should show his mobile number.

Battery module matching service | PriusChat

 

@robert Kwasny

Welcome to PC. There aren't many questions that can't be answered or problems that can't be solved using the combined knowledge present in this group.

Just a couple questions about your modules.

1. Can you explain how you're testing them?
2. What charger model you're using and the setpoints you're using.
3. What is the approximate average capacity of the modules you are re-using in your pack?
4. What are the first 4 digits of your modules serial numbers (decodes for manufacture date)
5. There's no perfect answer for one and two, it's just so I can understand your methodology to help with matching.

 

That's quite a range of manufacture dates. 2005 (G) through 2015 (Q).
Using those charge and discharge rates, what cooling are you providing to the modules? They normally have forced air flowing downward between the modules. The ends are sealed against each other, so there's no path for air to escape the sides.

Another item that comes up is the wire gauge you're using for those rates. I use 16ga speaker wire in my setup. 2.0 amps charge and 1.5 amp on the discharge. I see relatively minimal voltage losses. I use these setting mostly because it fits my schedule very well, allowing 2 cycles per day. One starts before I leave for work and then another shortly after getting home.

The chargers I use are limited to dissipating 10w on the discharge side, so I use a 1.5 amp discharge to 5.8 vdc. Even in this case, remember the charger has to be at a lower voltage than the battery terminals in order to create a discharge. Measurements have shown, on mine, that the battery terminal voltage is typically ~0.15 volts higher than what is being seen at the charger/discharger. So a 5.8v setpoint at the charger is actually ~5.95 at the module. At your higher current rate, and depending on wire size, you could have a significantly larger difference.

I do 28 modules at a time, sitting in a test rig that uses a Gen 2 case bottom, clamps and cooling fan/ductwork at full speed flow. On my charge side, using 2 amps, I use an 8200 mah cutoff. Mostly based on an 80% guesstimated charge efficiency and estimating the heat generation near the end of the charge. After a few thousand modules, for me, these settings work pretty well.

Are you experiencing any heat generation or swelling issues at the modules? NiMH modules hate cycling when they're hot.