Where are all the Hymotion purchasers?

Is there braking regen to the stock HV battery while the Hymotion pack still has charge ?

 

Yes, from what I have seen, regen continues to work normally, charging the stock battery.

 

chogan2,
Nice to see your install complete. 2 thoughts. Hymotion does reccomend a seperate GFCI circuit. Like you I have seen 1100 watts during a charge in the first 5 minutes. Also hopefully you received an extension cord with your kit (I didn't, but the manual stated you should). I was using a 100' orange extension cord that I had. After getting 2 incomplete charges last week with the kill-a- watt meter in the circuit, I checked and the extention cord I had is 16AWG wire. Probably not the best for 1100+ watts of sustained draw. I built a 12AWG cord Saturday and I will see if I get anymore short charges.
#2. I have easily seen 40-50+ MPH glides once the ICE is up to temperature. I'm sure that you will after a few more days

Sage, for your question I would say no significant regen to the Stock HV pack.

I still look forward to everyones experiences.
Chris

 

Too bad about losing most regen capability.

I don't have gauges to give data, but my impression from driving a stock Prius is that the battery icon can show all green, but still have some room for extra charging.

Perhaps the Hymotion electronics/control feed into the stock battery can be tweaked just a bit to allow this feature to return.

 

Short charges. I got another one yesterday. Wonder if they have a little software bug, or whether it's something I'm doing. First time that happened, I assumed I had thrown a breaker, but I don't really know (new house, never thrown one, figured I might have the kind that'll reset after overload.)

The only thing we clearly have in common is the Kill-a-Watt.

The instructions say GFCI with no timer or meter in the circuit, but in interpreted all of that as being for safety only, not for getting the car charged.

I can't believe that having a kill-a-watt in the circuit would mess up the charge cycle, but I'm going to swap mine out for an old-fashioned inductive ammeter and see if the short charges stop. If so I'll report that back here.

I have a 25' 14ga cord, but that's not the issue for me. My garage is at the opposite end of the house from the from the electrical service connection, so I have a long run of 14 gauge house wiring before I even get to the extension cord. I notice about a 10 volt drop at the wall socket when the car charges. But the highest amp draw is the first half of the charge, and the car seems to complete that OK -- just doesn't complete the charge.

Anyway, several people have now reported short charges. The only common item seems to be a meter in the circuit. I'm taking mine out for the time being. I've sent an email to Hymotion describing the issue, and if they respond I'll post it here.

 

Was the inside of the car really hot or was it really hot outside the day you was charging? I have noticed that on a really hot day it will only charge about 2kWh and quit. After a few hours of it not charging I unplugged it and plugged it back in and it finished charging. I have not had a hot day and a few days off to see if it will start to charge again on its own yet.

The kill-a-watt should be able to handle the load but it is a cheap consumer grade product. I have not used mine to track the kWh because I bough a more professional product call a Watts Up? .Net. Its a lot more expensive than the kill-a-watt but it allows me to monitor the usage over the internet. the .Net version costs about $236 but they have a basic Watts Up? meter for $96 but I don't think it has any data recording.

I have not had any charging issues beside what I think is a heat issue.

 

Ah, heat, I hadn't thought of that. That's a far more reasonable explanation for an intermittent problem, particularly as the ambient temps were pretty high this past weekend. Thanks, I'll look into that.

EDIT: Yeah, heat buildup is looking like a pretty good possible explanation. I opened it up and took a look, and the installation of the exhaust vent is pretty cheesy. There's a rubber flap that's clearly intended to prevent blowback of hot air into the battery compartment, but they ran a cable through the vent opening, thus preventing that rubber flap from sealing. I'm going to open it up and watch it on the next charge, and if that improperly sealed exhaust vent opening leaks a lot of hot air back into the battery compartment, I believe I'm going to slit that flap so it'll pass over the cable and seal properly.

 

I did think of the heat. The 2 nights that mine short charged the day temps were in the 80sF with the dewpoint mid 60sF. The manual states up to 60C (140F) If the temp is reaching that high in the battery compartment the venting is definitely a problem. A good note would be is how warm the cabin may be in the winter. I'll go trace my vents when I get a chance. I would hope that a cable over the vent flap would not be a standard install method.
Chris

 

The only time my pack never finished a charge on its own was when the car was setting in the heat all day.

I'm just wondering if there might be a bug in the charging program that does not allow it to finish a charge after the batteries cool down. The only way to find out is to let the car sit in the sun all day and run the pack down. Then let it charge for a few days and monitor what happens. Unfortunately I don't think there are any hot days left here for me to do that kind of test. Plus its hard for me to get a few days off in a row to do that kind of test.

 

On the "short charges", forget my theory about inadequate ventilation caused by an oddly installed flap in the exhaust system.

Far as I can tell there is essentially no ventilation of the battery during charging.

I watched mine charge last night. I could barely sense the air flowing into the intake (quarter-sized hole in the support casing under the battery), could not sense air out the exhaust at all (though the exhaust fitting did get warm after a while.) The fan noise was quieter than a typical PC fan.

Clearly, if that's running right, the ventilation during charging is not supposed to dissipate any significant amount of heat. The mismatch between the tiny air intake under the battery and vastly larger exhaust housing tells me the same thing. You're not cooling the batteries, you're only cooling the charger. Probably, that fan cools some part of the charger, and the tiny little intake under the battery is for cooling the charger only. The exterior of the battery pack itself never got more than modestly warm.

Which makes sense, I guess, as the battery only has to dissipate about 1KWH of energy over 6 hours or so (excess of 6KWH input and the 5KWH total charge for a fully depleted battery). Or so. That's in the neighborhood of the heat of two 100W old-fashioned incandescent bulbs. Should be no problem dissipating that through the surface of the battery pack.

So, assuming mine's running right:
1) The ventilation during charging is negligible.
2) It's ventilating some component of the charger, not the batteries.
3) Back-of-the-envelope says you shouldn't have to ventilate the batteries while charging -- not enough heat generation, assuming the pack has reasonable internal heat conductivity.
4) If it's a heat issue, it's the charger overheating.
5) Maybe that would be solved just by leaving the last segment of the Prius cargo area floor open to the ambient air (so the air intake gets cooler air in.)

So that's my proposed solution -- I'm just going to flip the last segment of the floor open when charging, open the hatch if possible, if I get another short charge, and see if that makes the problem go away.

Anyway, given the tiny amount of airflow, I can definitely see where there could be an issue if the thing was designed to work in a lab (with room temp ambient air) but now is being asked to cool the charger with air from the inside of a car that was sitting the sun. It also seems possible to me that you're not going to be able to charge the car reliably under those circumstances. Say, trying to charge at a public open lot in the summer, where the car is in the sun and you need to keep the widows rolled up. You'd need an external air intake connected to the itty-bitty air intake under the battery (which I now interpret as the charger air intake), and you don't have one.

 

I got a call back from A123. I'll post what I know here and in the other thread on incomplete charges.

They purchase the charger component.
They have had some customers with issues that appear to be due to using an extension cord with too small a gauge or too long a run.
The issue of heat as a factor has not come up before.
The system is designed so that heat should not be a factor.

In my case, I already noticed a 10V drop at the wall socket when I charge (which is more than I ought to get, in theory, based on 14 gauge house wiring.) And I'm using a 25' 14 gauge cord. My guess, as of this moment, is that heat = AC use = momentary voltage drops, and that my partial charge issue is the same as the partial charge issue for people who used narrow-gauge or long extension cords.

Bottom line: at this point, I think it's a low voltage issue for me. I'm going to get a shorter 10-gauge cord.

 

I have had the same issue with my Vectrix electric scooter. Never use an extension cord longer than 12 feet. Also need at least 13 gauge.

The Vectrix scooter draws 15 amps at 110 volts. The maximum watts is about 1600 watts during the charging process.

I have been told that the Hymotion battery charging process is about 10 amps at 110 volts. So about 1100 watts would be expected. I will know more on Monday (after Hymotion installation) when I run this on my energy meter equipment.

Until we hear more from Hymotion, I would recomment that you try to use a cord no longer than 12 feet.

 

I have a 12 gauge 50 foot cord on a GFI outlet and have been using a kill a watt unit. Tuesday (10/7) will mark two weeks with the L5. The voltage drop is less than half a volt during charging. The circuit run from the basement circuit box to the outlet is 10 feet.

I too am recording 1100 watts during charging.