Good afternoon. Read many of the posts, and had a question.

I've got 2 troublesome packs. One throws 1600 & 1449, and the other throws 1600 & 1570.

Looking to salvage sticks from both to make one pack to get me by a bit longer as the car has well in excess of 200k now.

Which charger would you recommend to charge/discharge sticks to determine which are go-forward candidates to make it into the installed pack? I've read good and bad on the IMAX B6.

I've also heard that sticks on the interior of the packs are more susceptible to damage as they don't get the air outer sticks get. Hopefully, I'll be able to visually detect bad ones with outer burning, but just in case, I'd love to know which individual charger you recommend to evaluate each stick.

Thanks in advance for your advice

 

Are all these chargers rated about the same? Is there a better way to identify bad sticks within a pack?

 

"these chargers" implies that you've included a list of chargers. If you have included any information of that kind, it did not come through.

P1449 likely means a failed cell, but it could also be temperature issues. You need to blink the codes to find out WHICH P1449 you have.

P1570 is again likely a failed cell as it is tripped by one or more of the 10 voltages (every 12 cells) monitored beaing out of spec.

B6 are cheap, and they are WAY overpriced at $13 for the chinese knock-offs. They are garbage. Additionally, stick testing is almost always done incorrectly.

Here's my recommendation:

Buy a Hybrid Automotive Prolong reconditioning package (I am an authorized installer, but I get nothing for recommending them).
Buy a BT-100 12V load tester (or equivalent).

Recondition each pack by:

1. 24 hour charge
2. discharge to 96V per HA instructions
3. 29 hour charge
4. discharge to 60V per HA instructions
5. 29 hour charge
6. discharge to 60V per HA instructions (NOT 12V)
7. 29 hour charge

Let it sit for 7 full days

Test each stick as follows:

1. MEASURE AND RECORD ALL 6 CELL VOLTAGES to X.XXX accuracy (can be done by poking through the shrink, barrel of each cell IS the (-) terminal). Use the same VM for all readings.
2. Affix aluminum spacers to end of stick with long bolts.
3. Attach BT-100
4. Attach separate voltmeter to stick to read OCV (tester VM is unreliable).
5. Record separate VM stick voltage
6. Apply load for 10 seconds
7. Record separate VM stick voltage (observed voltage immediately prior to termination of load)
8. Terminate load
9. Allow tester to cool in forced air flow for 2 minutes between tests.

Good sticks will have < 0.01V TOTAL variation between the six cells and may work for years.
Okay sticks will have < 0.03V TOTAL variation between the six cells and may work for years with periodic grid charging.

Compile all the data in a google sheet for all the sticks/cells:
40 rows containing stick #, start V, loaded V, six cell voltages, total voltage (sum of 6), max minus min voltage.

It will be easy to select the best 20, which ones should be kept as spares and which ones should be flagged as crap.

Additionally, the purchase of the HA unit means you now have a means of easily and reliably maintaining the pack and maximizing its life.

If you pursue my recommendation, I'll be happy to help with subsequent interactions and data interpretation. If you insist on stick testing, you're on your own. I don't like to watch folks slam their head into a brick wall repeatedly.

 

Thanks for the detailed reply. I was referring to IMAX type chargers, asking if they are fairly rated the same as far as effectiveness.

In your signature, you detail a process for building your own charger/discharger. Is that still something you would consider a viable option if cash was tight?

Thanks Steve

 

It is still viable, but it is completely unsupported. I will not answer questions. Use at your own risk.

Regardless of what you do, ensure that you NEVER charge the pack without FORCING air through it. NEVER charge it in-place w/o driving the car's cooling fan. The car's cooling fan should be driven with a PWM controller. You can't apply a voltage to the fan and make it work UNLESS you ground the PWM line and can supply at least 8A/12V to the blower.

 

Ok. I blinked the sub codes out Steve as you mentioned. And its 73. Overheating pack. After that, I cleared the codes, and the pack was discharged. So, I started the car, and ran it at around 3250 rpm to charge the pack. After about 5-10 seconds the fan kicked on, and ran until the charged stopped at about half the gauge reading. I let it idle, and it completed the charge by the gauge. Drove it about 40 miles, no lights, everything normal. I had to floor it to make a hill, assist came on and ran the battery about halfway down, then the IMA light came on. Stayed on the rest of the day. Same sub code, 73, pack getting hot. When cold, the pack acts normal. But under heavy charge or discharge, gets the 73 overheating code.

Wondering if there could be an obstruction keeping air from the pack, but not sure how that could happen.

 

Also, forgot to mention... 73 is the only code blinked out on the IMA light. Just blinks over and over.

 

73 indicates that one or more of the three cells being monitored is overheating.

The inlet is on the rear deck, so if you haven't blocked that, it's pretty difficult to block the airflow. When the fan is running, you should be able to tell if air is being drawn in.

Another way to cripple the cooling system is to run with the IPU cover off OR if you failed to get it sealed. Fan works by sucking air out of the IPU cavity and discharging it into the trunk. If the IPU cover leaks or isn't present, it basically bypasses the battery.

 

Also, outside temps are in the 50s. Very cool.

 

IPU cover being the large metal sheet under the back seat? If so, that may be the problem. I have that cover bolted in place, but the middle metal cap that covers the breaker was not attached during the test ride today. So, if the IPU cover is that large metal sheet, I'm assuming having that center cap with the 2 bolts removed would cause air to escape there rather than make it to the pack. In any event, I'll put it on right now,