I don't know for certain, but I believe the BeeMax are cylindrical cell packs.

I wanted to see the current value. The pack was discharging at 29.84A. That's very useful for diagnostics. See the attached chart.

I drew a line at 0.2V below the highest block (this assumes the highest block is good). Anything above the 0.2V line is probably good. Anything above 0.3V below the high. Everything else has 1-2 bad/weak modules in it as you get farther from the 0.3V line. I would estimate that the six best blocks are probably fine for DIY.

NOTE: While my experience is that the damage is permanent with G3 Prius and Camry, it's possible that the same could be caused by low capacity due to voltage depression (can be fixed with reconditioning), particularly if you're in a mild climate. I think the 12.XX are gonners in any case. This is USUALLY not true when the blocks look like this. Excessive voltage depression usually maintains a tight voltage difference, but the pack exhibits dramatically reduced capacity.

If you plan to use the HA system on this battery before you do anything major, there are ways to assist in diagnosing bad modules during the discharge and assessing overall health by recording time and voltage data, i.e., a log of times and voltages. Best results when you record time to 245V, 224V and 204V. You can actually estimate battery pack health and capacity.

 

Thanks a lot for the graph as also the advice, Keith. Much appreciated.

One question regarding installation of the HA harness. The instructions call for disconnecting the 12V. I am afraid that could cause the learned values on idle, etc., to be gone and cause issues when I reconnect the 12V. I am planning to contact HA about this, but have you done any harness installs without disconnecting the 12V? I am planning to place a trickle charger on the 12V so it doesn't drain while I have the trunk open.

Thanks again.

 

No concerns with disconnecting the 12V. You can do the install w/o the disconnect, but it's beneficial because it clears all codes and pending codes. The car re-learns very quickly.

 

Thanks again, Keith. I will update once I receive and install the HA harness and try reconditioning the pack, FWIW.

 

Again, I vigorously encourage you to record times to:
245V (3 discharges)
224V (3 discharges)
204V (3 discharges)
163V (termination of first discharge as well as when 2nd and 3rd pass through it)
102V (termination of 2nd and 3rd discharge)

IMHO, the recommended discharge to 20V is not necessary. I rarely find benefit discharging below 0.5V/cell. It can get you a little more goody out of the worst cells, but it's not necessary, and on a severely deteriorated battery, it could drive marginal modules to failure when they might otherwise mostly work.

I modify the recommendations here:

https://hybridautomotive.com/pages/sd

as follows:

Above 224V, up to 200W
Above 204V, up to 100W
Below 204V, up to 40W

ALWAYS use the same wattage bulbs in both sockets.

If you want easy mode and don't mind the wait:
100W bulbs down to 204V
40W bulbs below 204V

Whatever you do, be consistent.

When you switch bulbs, the voltage will rise initially. Ignore this. Simply record the total time to the target voltages.

Lastly, the first discharge is going to take a LONG time. I would allow for 12-20 hours. This will take so long because a large portion of the process will occur at lower current/voltages. After reconditioning, subsequent discharges should take less time as the discharge is occurring at higher voltage/current. You should notice a BIG drop in the higher wattage phase of discharge time from 1st to 2nd if the battery is responding well to reconditioning.

If all your discharges take a long time with little or no reduction in discharges times above 204V, then this is evidence of little/no response to reconditioning and indicates damage.

Lastly... if you really want to get detailed, you can do the discharge with the cover off and check individual module voltages at those prescribed pack voltages. This can really help you identify good/bad modules.

 

Many thanks for the guidance, Keith. I will report back in a few days. Thanks again.

 

Hi Keith,

I just installed Torque Pro on my phone and I am able to read the 14 block voltages on my 2010 Prius but NOT on the Camry. I understand the Camry has 3 additional blocks, but I was hoping to at least look at the first 14 blocks. Looks like I need to get the mini VCI Techstream. I am seeing various versions of Techstream online. Any recommendations on which version I should get.

Thanks in advance.

 

Ordered the 13.0.022 version off of eBay. Thanks.

 

Torque Pro PID for the Camry are different. I've never encountered them.

In addition to what I mentioned in my email, you can use "Hybrid Assistant" with the same OBD reader. It will automatically recognize your camry. You'll probably hate the interface, but you'll eventually grow to accept it.

EDIT: it also has a battery health check that gives you a lot of insight.

 

Thanks a lot for the pointing me to Hybrid Assistant, and also for the message with a link to Techstream, Keith. I will try Hybrid Assistant; I don't have a windows 32bit laptop. Thanks again.