Running An Insight Without the NiMH / High Voltage Battery

[koolkev]

I would like people who have tried running the car without the high voltage (HV) battery pack to report how that worked out.

I have tried to run my insight without the HV battery, because it is getting IMA failure lights, and wanted to test/recharge the battery, but with the relay board from the pack installed.

The 12v battery died after about 30 miles. At night with my wife in the car. Bad press for the car.

I reinstalled the pack and ran the car for months without incident. I am still getting IMA warnings. I have since had problems with the 12 volt battery (I think related to an old battery and period of very infrequent use) and replaced the 12v battery and the car is running ok,

Again I would like to hear from a sample of people who have tried running without the HV pack and how it worked for them. Are there a tricks? Is there a common failure on the relay board or some process to make it work without the pack? Can it be done indefinitely?

Hopefully this will aid people in getting the pack repaired/reconditioned or allow saving hauling around 40+lbs of dead weight.

[CigaR007]

These threads might be useful to you !

DIY Solutions to Honda Hybrid Battery Problems (Insight, Civic, IMA)

Analyzing, refurbishing/repairing a dead hybrid battery pack (2000 Honda Insight)

The search function should also yield other threads on the subject matter.

[MetroMPG]

Are you only interested in running the car with the pack physically removed?

My understanding is that it can be done if the junction board is left in place, connected to the other IMA components as it normally would be.

I ran my car from July through November, 2011 with the pack/IMA disabled, but still in the car: the big breaker (ON/OFF switch on the junction board) was in the OFF position. Best to do this if you're having pack problems anyway, to avoid doing further damage to the cells.

The car reverts to using its conventional 12v starter, and obviously all hybrid functions cease (assist/regen/autostop). The DC-DC converter still worked fine, and kept the 12v battery charged (with one irregularity: sometimes there was a delay before the DC-DC came "on" for a moment after starting).

This thread on insight central seems to confirm this, and comes from the horse's mouth (Ron, of hybrid battery repair): Drive without the IMA/Battery? - Insight Central: Honda Insight Forum

[sendler]

I ran my 2001 Insight with a defective battery for 9 months. It lasted 6 years and 90,000 before the IMA light started coming on. I could do a hard reset by disconnecting the 12v battery which would let it function again for a while but it got worse and worse until the point that the charging immediately shut down every time and it wouldn't charge the 12v anymore either. Luckily this was right after Honda instituted the 150,000 mile warranty so they GENEROUSLY gave me a new battery and two new controllers which are still going strong 4 years and 110,000 miles later. The car was much slower without the hybrid assist but I am 80% highway so the fuel mileage was almost the same. When these batteries die, I will probably just try to convert it to run the 12v systems and skip the IMA. The 1 and 2 synchros are shot so I have to double clutch any down shifts but it is still a great commuter car. Once I fix the rough idle. Injectors?

[MetroMPG]

Before I put the pack back in the car, I could hook up the junction board and let you know what I find out (in terms of DC-DC operation).

[IamIan]

The default / no signal condition for the DC-DC converter is to charge the 12V battery ... converting HV to LV ... the car sends a signal ( comparatively high voltage on a single wire ) , to stop it from charging the 12V ... if you cut ( permanently or temporarily with a relay ) that control wire ( the wire signal goes to low ) you revert to the default condition of charging the 12V from the HV ... as long as the DC-DC convert is still connected to the HV.

The reason for the battery junction board is it is an easy way to keep the HV supplied to the DC-DC without significant car modification... If I recall correctly one of the control modules should also be unplugged... if there is no HV battery at all in the car.

Pictures and other descriptions can be seen on Mike's description of his use of the DC-DC enable for the FAS option for MIMA.... HERE.

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Another option ... if one wants to run permanently without the IMA battery ... the IMA motor always puts out AC power while it is spinning ... which it does whenever the ICE has any non-Zero RPMs ... If your only goal is to get alternator action for the 12V side ... you can do it with less weight and space than the module which includes the DC-DC converter and the IMA motor drive inverter.

This can be done a variety of ways ... from simple ( properly sized ) transformer and rectifier ... to more complicated switch mode AC-DC circuits ( which can be smaller , lighter, and more efficient than the simple transformer and rectifier , but is much more complicated ).

The Mechanical Load the IMA motor will pull down the drive line with ... will be a function of the electrical load pulled out ... always less than 100% energy efficiency conversion.

[jamesqf]

Originally Posted by sendler

Once I fix the rough idle. Injectors?

Maybe, but remember that the IMA system is also acting as a dynamic balancer for the engine.

[sendler]

Originally Posted by jamesqf

Maybe, but remember that the IMA system is also acting as a dynamic balancer for the engine.

My IMA is fine now.