[Sparky5501]

Hi all,

After installing the PC690 battery I've realized it's useless to help jumpstart other cars. My girlfirend's Alfa died and so I tried jumpstarting with my tiny 12V. Hah! It cranked her engine over but not like the full 600 crank amps would from her battery.

So, ever since I tried to jumpstart her Alfa my SOC has been fluttering around half. Should I force a recalibration of the system?

This has been since the weekend.

 

[Yves M.]

Since you apparently do not have the CEL or IMA light On, I suppose everything is fine. Maybe an MCM reset would solve this annoyance.

One thing to remember is not to jumpstart with your engine On. It needs to be Off and the key removed from the ignition (in case you are in a DC-to-DC converter On situation. Boost from the battery only.
I am sure you did though.

 

[Sparky5501]

Oh Shoot! I had the engine running. :shock:

Luckly my SOC was only one tick from full so I don't think it was in DC charge mode. I guess my IMA must be confused now... I'll do an MCM reset tonight and see what progresses morrow.

Argh, bang head on desk... :?

 

[ext1jdh]

I had no problem jumping my fiance's completely dead Jeep a few weeks back. I had the engine running and forced myself up to a full charge before turning off the car though.

I did get some funny looks from passers by. My itty bitty spacepod jumping her comparative giant without the engine running...

 

[Yves M.]

Hi,

I wrote that because (it is the same thing with an alternator) if the current draw is too big for the battery, the DC/DC converter will try to compensate for the 12V battery's voltage going down. If I remember the DC/DC converter is about 75 AMPS.

(note that the numbers below are for explanation purpose)
If for some reason (big engine to boost or a shorted starter) starting the dead engine draws 750 amps and the Insight's battery can give 500 amps then the DC/DC converter will try to give 200 amps. Which is too much.

 

[Foxpaw]

Is that true? It doesn't quite add up for me - if the DC/DC converter can only do 75 amps, and you try to draw 250 from it, you should only get 75 and the dead engine would not be cranked as fast. Even if this was not the case, the D cells in the battery pack can only supply about 80 amps max (or so I read elsewhere on this forum) anyway.

Granted, it is possible that the DC/DC converter steps up the current while dropping the voltage, like a switching power supply might, but it seems unlikely that it would operate in that manner and likely behaves more like a regulator.

I have attempted (and failed) to boost my Mercury Topaz from the Insight. At first I thought, "this'll be a snap with the 144 volt pack" but then I realized, "yeah, except the DC/DC converter can't cough up that much power on demand.", to which I replied with various obscenities as a potential buyer was en route to test drive the Topaz and I'd left the lights on and if it wouldn't start when the person arrived they might think it had some chronic problem.

But anyway the point is the DC/DC converter did not seem to be damaged but instead seemed to be current-limited.

 

[Yves M.]

I wounder if John Wayland reads this forum, he is an "expert" in this stuff.

 

[Sparky5501]

Well, amps aside, my SOC has returned to a normal level. On my way home last night I was going to force a MCM recal but by the time I got home the SOC was back to normal.

Actually, when I used to have the stock Furikawa battery I was able to jump start my girlfriend's Alfa several times. Several times you say, what's wrong with her car? There is a stupid little red flashing light on her stock radio that puts a parisidic drain on the battery. And, since the Alfa is only driven about one a month it eventually gets a dead battery.

Anyway, I will no longer jump start any more cars with my PC690 batt. :wink:

 

[IHonda2002]

I had this discussion in Aug of 2002 on the Yahoo Honda-Hybrid group after jump-starting my daughter's car, leaving the engine off as John Wayland suggested. Some responded saying that I should have left the car running, otherwise you run the risk of draining the Insight's 12 volt battery. I never did feel that I got a satisfactory answer on how to jump another car. Luckily, I haven't had to since, but I'd still like to know - engine running, or engine not running.

 

[Armin]

keep the engine running!

I remember the discussion on yahoo a while ago. I was one of those saying you should keep the engine running (or at least in auto-idle-stop). Here's why:

The little 12V battery in the Insight is too small to start most gas-guzzlers by itself. You need all the power you can get and the extra 75A from the DC/DC come in quite handy.
I am absolutely certain DC DC converter has current limitation at 75 A. If it didn't, it would blow up if a short developed in the 12V battery (a common failure for lead-acid). Honda can't be that stupid! It is common for switched power supplies to go into a constant-current mode when the capacity is exceeded and that's surely what our DC/DC does.

The DC/DC converter is actually a microprocessor controlled fairly intelligent piece of equipment with a number of built-in protection features. The little lead-acid battery is totally dumb. So it is more vulnerable to suffer deep-discharge and die in an attempt to jumpstart a large engine. You want to help protecting it by running the DC/DC, not the other way around!

But the best way to protect the little battery is to do what you always should jumpstarting any car with any other: connect the jumper cables (with the donor cars engine running) and then wait 5 minutes! This will allow the receiving battery to charge a little, so it will deliver a sizable portion of the current needed to start the engine.

 

[Madeline]

I jumped a midsize sedan with my Insight a month or so ago... We did the usual thing, the Insight running, and revving it up as the other guy tried to get ignition. It worked fine, I noticed no change afterwards in the battery level of the Insight or its charging habits. Note, my car is new, and so the 12V battery is new as well...

I was happy that I could use my Insight as a normal car in this instance, too.

 

[Armin]

the Insight running, and revving it up as the other guy tried to get ignition.

Note that while this helps with ordinary cars, there's no need to increase revs on the Insight while jump starting, since this will have no effect on the output of the DC/DC converter.

In fact, I'm waiting for the chance to jump start someone with the Insight in auto-idle stop. That would be so cool! 8)

And if you're worried about draining the 144V battery, this won't happen. Even at idle, the IMA can deliver enough current to the 144V battery to drive the DC/DC at full load.