Unit-02 Red Honda Insight

[Daox]

Woohoo. We definitely need more info on this!

[Natalya]

The biggest problem is finding out how to fit everything in the IPU case and to secure the batteries.

Pic 1:
I cut a hole in the side of the IPU case using an angle grinder. I then zip tied a sliced rubber hose to cover the sharp edge. This was a tight squeeze because of the rubber hose. Cut 1 extra half inch to the right if you can and it will fit great.





Pic 2:
Building brackets for the batteries to rest on was by far the hardest part. This set is imperfect and needs to be modified, but it works for now. I need to get a TIG welder.





Pic 3:
Fitment test with bracket and hole cut in IPU case. Notice the junction board contacts are going to short on the bracket.

[Natalya]

Pics 4 and 5:
Junction board with wires. This was the second hardest part I copied a guy on Insight Central and tried to get the wires as far away from the battery side of the junction board as possible. The bus bars are very fragile and I broke one. But that's okay I disconnected it and routed the wire straight through the hall effect sensor to where the bus bar had connected to the junction board.





For the other 3 I drilled sideways into the circular extrusions surrounding the terminals and pushed them away from the battery side of the board. If I had it to do over again I would see about routing those wires to the junction board like that other wire. If I re-routed the one green wire to NOT cross over the other wire the board could sit flush against the batteries. I might do that in the future.

[Natalya]

Pic 6:
Same picture as my post on page 8. This is everything assembled. The two battery computers are in front of the IPU case underneath the horizontal structural support bar. The orange wire with the pink foam thing at the end, in the foam is a home-made "BCM Fooler" which is a simple circuit board designed by Peter Perkins on Insight Central.





Pic 7:
Circuit diagram for the BCM fooler. The negative lead goes to the black wire terminal at the top of the junction board. The positive lead goes to the spot at the bottom where you typically attach a grid charger. I omitted the LED as I did not have the correct type on hand. The diagram calls for 10K Ohm resistors but I used 20K Ohm resistors and it works fine. They just have to be in that range and all of the same value. Peter also sells the boards either pre-built or pcb + parts if you want to buy one that's nicer than the one I hastily cobbled together.

[Daox]

Thanks for sharing more!

What are those LTO cells from? Where did you get them? Cost?

[Natalya]

https://greentecauto.com/product-cat...osed-batteries

There is quite a selection. I got the LTO batteries. But there are guys on Insight Central who have used some of the other battery types.

[Natalya]

Yesterday I got terminal caps installed. They are Blue Sea 4009 cable caps.

https://www.ebay.com/itm/BLUE-SEA-40...oAAOSwuTxWBwvB

Using regular scissors I cut the back ends off to help them fit better. They're a great fit on the terminals with the spacers, tighter on the ones without. It may be worth it to add spacers to the regular terminals to make these fit better.

[Daox]

Very nice work! Are you now running higher system voltage? BMS?

[Ecky]

Originally Posted by Daox

Very nice work! Are you now running higher system voltage? BMS?

The LTO cells in certain configurations are within range for the stock computers and can be run without a BMS, so long as you (infrequently) check the balance of the cells. My guess is "no".

[Natalya]

Originally Posted by Daox

Very nice work! Are you now running higher system voltage? BMS?

Yes, as Ecky said, the voltages are very similar to the stock battery. I don't have much experience with OEM packs that weren't deteriorated, but from what I've heard they usually operated in the 150-160 volt range. The batteries I'm using have only fluctuated between 160 and 165 volts. I've seen like 158 during assist when it was already sitting down at 160, but I'm not seeing it rest above or below that window.

The OEM computers will allow the batteries to charge up to 176 volts IIRC.

But volts aren't the main difference. The main difference is kilowatt hour capacity. The LTO setup I have is 3.3 KwH while an OEM NiMH battery is around 1 KwH. That means the voltage of the LTO pack will go up and down more slowly as the pack is used or recharged.

Something I am thinking about doing, going off a conversation I had with IamIan at Insight Fest 2019 and with him earlier in this thread, is installing a grid charger harness and then trying to drive while using assist as much as possible during the day, and use EOC instead of regen for hypermiling purposes. Then when I get home I could top it off with the grid charger. But I probably won't sort that out anytime soon.

I have more to do on the setup first.
- Need to route the DC/DC converter fan to the air port it had in stock configuration.
- Need to put the IMA battery cooling fan in a more useful location.
- Need to investigate better wiring for the connections between the green wires and junction board.

Optional:
- Indicator LED on BCM Fooler + relay to activate it only when car is on
- Larger voltage display up front (currently only using OBDIIC&C)