Honda Insight Forum banner
441 - 455 of 455 Posts

·
Super Moderator
Joined
·
9,520 Posts
I don't know how the separation happened but I have the pack ready for welding tomorrow.
This is an interesting crack. It kinda looks like a fatigue related crack. Maybe that large cable was operating with a lot of pre load on it. That could maybe cause the crack?
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #442 ·
@jime. Thanks for your thought provoker. The connector piece under where the cable connects had a slight turn/twist/angle to it. I would agree that this crack didn't happen after one torque event, but it strikes me as peculiar this would happen enough times to cause the damage. Second thought, I've had the batteries out several times and the cables disconnected /reconnected multiple times. I usually use an electric torque tool but the first instant it stops/starts to torque, I quit. All the other joints /connections on that pack look good. I guess I'll have to be more careful in the future and warn others of what happened to me.
 

·
Registered
Joined
·
1,922 Posts
I have found that these tabs are very easily worked to failure. So it would not surprise me that a twisting action from several installations and removals would lead to failure. The shape of the jagged break suggests this is the cause.
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #444 · (Edited)
I thought I'd document my mods and updates on my own thread instead of the generic "what did I do today" thread. This will be more useful to me.
Today I removed the standard half-shaft axles and replaced them with the larger Trak Motive brand purchased at Rock Auto.
Several weeks ago I removed the throttle body and the butterfly inside to give each a thorough cleaning. I then made the TPS adjustment using the Hybrid Revolt mod-box. Now I find it difficult not to stay in lean burn (a bit of an exaggeration, but the green light is on a lot more now).
When the throttle body was off I decided to file the input to make it more of a venturi effect.
Automotive tire Rim Motor vehicle Gas Vehicle brake
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #445 ·
I've got a question about grid charging my LTO pack. What I'm considering is to put a wire at the end of each 12-cell block, or maybe each 24-module so I can connect to the grid charger will keeping the whole system connected. My question is am I looking for trouble leaving everything connected leaving the system connected when I grid charge each 12 cell pack?
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #447 ·
Thanks Peter. Just to verify: I can leave all modules connected in the driving configuration and connect each pack, individually to enable grid charging. Correct?
To answer your question it's a real PITA to disconnect everything in order to grid charge. I don't want to disconnect anything in order to have the ability to grid charge all modules.
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #449 ·
"Why are you disconnecting everything to grid charge?"
I guess I've always felt it would be best to connect the grid charger to each individual entity.
 

·
Linsight Designer
Joined
·
3,927 Posts
Connecting separate grid chargers to each cell/module/etc is going to unbalance the pack... unless you have a BMS that can rebalance afterwards. There's really no reason to charge cells/modules/etc separately. Just get a charger that can handle the maximum charging voltage and you're all set. Without a BMS, you'll need to manually monitor each cell with a voltage meter.
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #451 ·
Thanks for chiming in @mudder. I've got a proper grid charger but due to the voltage boundaries of the LTO, I like to use an accurate, digital 30V DC power supply and charge modules individually, monitoring with an accurate DVM. The issue I have at the moment is one or two 12-cell modules have a variation of greater than 20 millivolts. I'm not exactly sure how to raise the low cell (s) to equal the highest one. Do I pump voltage into the module that equals the high cell so the low one(s) keep charging? Or, I guess, charge the LTO's as a unit and let the voltage sit to a point where all cells eventually equal each other? What do the high cells do while the low ones are charging, just sit there? Is excess heat burn-off occurring? Since my unit is not NiMH grid charging Li seems foreign to me; I'm just a bit tentative with Li cells. That sounds logical, and I read your LiBCM thread about grid charging but since I don't have a BCM and never felt the need, I've never grid charged the complete pack at once. Thanks in advance for your reply.
 

·
Super Moderator
Joined
·
9,520 Posts
I don't think I'd tinker with a 20mV variation. That variation is not troublesome yet.

I'm a bit reluctant, but here goes. When I set up a pack, I do my balancing by bring the high cells down to the low cell voltages. I do this by using jumper wires and a .3ohm ceramic power resistor to discharge the high cells a bit. The procedure is not personally dangerous for individual packs on the bench, but it can be highly error prone. If you try the procedure, be very careful. Use color coded wires and alligator clips, and mark the positive and negative ends of every cell in your pack. NEVER, EVER connect two cells in the same 12 cell subpack!

The above process takes a lot of time. A shorter route, if you can identify a few high cells, is to just use color coded jumper wires to transfer charge from high cells directly to low. Positive to positive and negative to negative. This can be extraordinary danger if you get the polarities wrong, so, again mark the polarities. NEVER, EVER connect two cells in the same 12 cell subpack!

The cell voltages will rebound by several milivolts, particularly when being discharged, so you have to go slightly beyond the equal reading to get to what you want. Wait several hours, and repeat the process.

I have never tried to balance a pack in the car. If I were going to do so, I would turn off the main switch, and remove all the little strap bus bars from the packs. That could save you from some potentially very costly accidents.

Great care is required. I'd use rubber gloves, AND NEVER, EVER................
 
  • Like
Reactions: minor4326

·
Registered
Joined
·
1,922 Posts
<EDIT>
Grid charging implies a specific purpose and procedure which if applied to lithium will damage it or possible destroy the vehicle. I've created a new thread that proposes to limit the term "grid charging" to apply to NiMH only, and suggest that we use an industry term (such as "L1 charging" or "PHEV charging") for PHEV-like charging of lithium packs.

This is because the mechanism in NiMH that that "grid charging" leverages to balance a NIMH pack at the top of charge does not exist in lithium and will cause a grid charger to damage the pack or possibly cause a thermal runaway.

If the goal is to balance the pack, @jime provides an approach that works (but don't just wear gloves, wear full PPE - including eyes, face, skin, clothing covering - since a slipped wire or tool can shunt hundreds of amps and violently create a metal plasma)

If the goal is to do L1 charging like a PHEV, a charger must be built that automatically shuts down when any single cell reaches capacity. This is not a simple build because it requires building in safety features. For example, the HCH3 BCM utilizes two separate voltage measuring chips which help detect failure if one is reading incorrectly; this can lead to over- or under-charge and a thermal event if not caught. Manually monitoring pack voltage is not enough because one will not observe the cell that's running higher voltage than the rest because the (1) the others average it down making it hard to detect without watching every cell and (2) the rate of rise increases very quickly after around 2.65 volts. One little bit of inattention and...
 

·
Registered
Joined
·
1,922 Posts
Today I removed the standard half-shaft axles and replaced them with the larger Trak Motive brand purchased at Rock Auto.
I missed this first time around! How is it working out? I have a set of these waiting to be installed. Do you like the change?
I then made the TPS adjustment using the Hybrid Revolt mod-box.
How does that box work? Is it a combination of a low pass filter to smooth out sudden throttle movements that can end lean burn, or remap the throttle so that the throttle is more open for the same TPS value which might allow a greater load before lean burn is terminated?
 

·
Premium Member
Chicago & Detroit
Joined
·
1,378 Posts
Discussion Starter · #455 ·
Thanks for the words about Li grid charging. I was legitimately leary of doing that. I'm still not sure how to deal with this issue.

Halfshafts: I apparently installed the driver's side incorrectly as it came out in <10 miles. I reinstalled the original and kept the new one on the passenger side. I love the slightly larger diameter new half shafts. It's noticable when I take off from a stop and not being totally smooth on the clutch. If I were short of funds I'd only buy the passenger side.

The Hybrid Revolt box seems to work really well. I was not able to get a good o'scope presentation for adjustment purposes but the directions tell how to set up 2/4 pots manually, and the remaining two affect TPS hi and lo settings. I find my car goes into LB very easy, I can accelerate (slowly) at highway speeds while maintaining LB, and the car goes into Stop easily as well.
 
441 - 455 of 455 Posts
Top