[olrowdy01]

You're referring to the end of discharge #2. I'm not sure what the recovery voltage was, because my daughter was implementing my (apparently not very clear) directions by text message, and the only data I have is what she wrote down. She couldn't explain it to me very well, but here's what I think happened...

What she described doesn't make a lot of sense to me.

According to your description of the Mean Well on your website, it shouldn't start charging unless the battery is at a minimum of 100V. Maybe it automatically kicked in once the battery recovered to 100V+, sometime between 17:04 and 18:11?

It was definitely charging at 18:11 last night. As of 9:11 this morning it had pushed the battery up to 164.6V. The charge curve looks the same as the previous two charge cycles so far.

We'll see. I definitely appreciate the more detailed write-up of the charge and discharge cycles you added to your website.

- Park [/QUOTE]

I misread the Mean Well data sheet and based on your initial experience with turning the charger ON & OFF in our private emails when it wouldn't output voltage with the 60 watt bulbs I thought you had to switch the supply ON/OFF to get to work again.

But based on what you found when the voltage was 9 volts and rising, I now realize what the HLG-60H-C350A data sheet means in this specification,

"PROTECTION - SHORT CIRCUIT ............ Hiccup mode, recovers automatically after fault condition is removed."

i.e. The power supply will not charge the battery if it is below 100 volts. But the charger will automatically power back on when the voltage rises to more than 100 volts. That's actually a good thing if necessary so the battery can recover on it's own before the charging starts again after a discharge.

I think my power supply may have a longer Hiccup fault time constant than yours that allows my 60 watt bulbs to light up right away.

I have already changed the following in the "Do a rejuvenation" section of the V2 DIY charger article.

"Here's why:
The power supply will not charge the battery if it is below 100 volts because a protection mode called 'Hiccup mode' kicks in. The charger will power back up when the voltage rises to more than 100 volts."

So that clears up why your charger started working by itself by the time you came home.

 

[MparkH]

Finished discharge #3, and was able to monitor the discharge myself and more closely. Actually, I did two discharges on this cycle.

INSIGHT CHARGE - Citrus/Silver

May 2022 DATE / TIME,VOLTS,AMPS,TEMP (F),NOTES,amps * 100,D(isharge)/C(harge) + R(est) chart length in columns = (hours / 4) + 1 5/2/2022 9:50:00,157.8,0.342,46,REST,34.2 5/2/2022 9:50:00,159.1,0.339,46,CHARGE,33.9 5/2/2022 11:06:00,163.3,0.344,47,34.4 5/2/2022 12:17:00,166.3,0.342,49,34.2 5/2/2...

docs.google.com

The first, long discharge (#3a) took the battery from 169.1V to 60V over about 22 hours. As before, there was a very long slow discharge until the battery dropped below about 138 volts, and then the curve rounded into a steep descent. At this point I began checking every half hour, then every fifteen minutes. I let it drop to 60V.

With the load disconnected, the battery quickly rebounded to to over 120V in about fifteen minutes. After resting overnight the voltage was 137.3V.

I wanted to see how long it would take the battery to reach 20V, so I started another discharge (#3b) this afternoon using the 25w/25w load, monitoring every five minutes. It only took 1.5 hours to bring the voltage down from 137.3 to 20V. With an hour's rest, the voltage bounced back to 131.3V.

The power supply will not charge the battery if it is below 100 volts.

While the battery was recovering from the deep discharge and still well below 100V, I tried turning on the charging circuit. As advertised, it did not try to charge the battery.

Now I am on to the last charge cycle. 30 hours to go, and the car will be back on the road. We'll see how she runs then.

Learning points so far...

(A) The 3-cycle charge and discharge battery conditioning takes a LONG time.

(B) The battery discharge requires careful monitoring once the voltage drops below 140.

(C) The battery voltage bounces back quickly from a deep discharge, but the battery will quickly drop again under load.

None of this is news to old-timers, but it's interesting for me to experience for myself.

- Park

 

[MparkH]

Final update...

I finished my full three-cycle charge and discharge battery conditioning. It took about eight days from start to finish. You can see the graph of volts and amps during each cycle in links elsewhere in this thread.

Here's a photo from near the bottom of the final discharge cycle...

The discharge is down to 41V and 0.08 amps (80 milliamps). The dual 25W bulbs are barely glowing. At 20V the lamps were not visible illuminated at all.

After the third charge and discharge cycle, I did one final grid charge for 29 hours. The voltage peaked at 173.4V, and after resting overnight the battery read 165.4V.

--------
The point of this of course is to rejuvenate the battery. So how does it drive? WAY better.

Before doing this reconditioning cycle I could drive around town without generally tripping the IMA light, if I was careful. I was still seeing a lot of recalibration and positive charging on the dash. If I got on the interstate or climbed any kind of hill, the IMA would trip out.

After the reconditioning, in city driving the car is flawless. Good boost, good recharge, no recalibration. In fact, the battery meter barely moves.

To really test the battery, I headed east out of La Crosse on State Road 16, which climbs steeply for 1.3 miles from the Mississippi River up to the top of the bluffs. I was able to mostly maintain 55mph in fourth gear with the boost almost pegged. I shifted down to third gear as the system suggested, and with boost was easily able to accelerate up the remainder of the hill. All this fun only depleted the battery gauge about 20%, and descending the hill with regenerative braking topped off the battery again.

I haven't had a reason to get out on the interstate yet, but I expect it will be fine on the big road as well.

Overall, I'm very satisfied with Ol' Rowdy's V2 grid charger and discharger. For less than $100, I've been able to refresh my battery to a very usable state. The car really is much nicer to drive with a solid IMA!

Based on previous experience, I hope to get about six months of service before I need to do the reconditioning cycle again.

I hope this thread encourages you to build your own grid charger/discharger. It is a fun and satisfying project. Feel free to ask any questions. And, one more shout out of thanks! to Ol' Rowdy for the design and assistance.

Blessings,

Park

 

[MparkH]

One last tweak to the discharger...

Ol' Rowdy's design doesn't read the amps on the discharge cycles - this is a quirk of the digital multimeter used in the design. I rigged my digital multimeter into the circuit to see the amperage data when discharging. Now I've found an old fashioned mechanical ammeter to give me that info.

DISCHARGE LOAD
$2.39 ... Porcelain lamp holder w/ switch (Menards #3634101)
$1.29 ... Porcelain lamp holder (Menards #3634091)
$4.99 ... Orange extension cord 10’ (Menards #3700433)
$1.99 ... 25W incandescent bulbs, 2-pack (Menards #3533160)
$1.99 ... 40W incandescent bulbs, 2-pack (Menards #3533161)
$4.99 ... 60W incandescent bug lights, 2-pack (Ace Hardware)

Add to that list...

$1.97 ... 85C1 Ammeter DC Analog Mechanical Pointer Type 500mA (AliExpress, ~$5 with shipping)
LINK: US $1.83 17% OFF|85C1 Ammeter DC Analog Current Meter Panel Mechanical Pointer Type 1/2/3/30/50/100A 50/100/200/500mA|Current Meters| | - AliExpress

TOTAL COST OF DISCHARGE LOAD $19.61

Be sure to choose the 500mA meter out of the several listed. In my testing, I never saw the discharge load go much over 400mA.

---
The meter is plastic but seems to be sturdy. Before installing the ammeter, I wired it into my discharge load to check that it would read on the positive side, and marked the terminals on the back with the wire colors.

The trickiest part was drilling the holes and cutting the notches in my discharge load's board to insert the meter.

I wired the ammeter, checking the color codes I'd marked earlier. The ammeter is in series with the light bulbs, so one wire attaches to a screw terminal on one socket, and the other attaches to a screw terminal on the second socket.

Now when the discharge load is connected to the charger, I can read the volts off the digital meter on the charger, and the amps off the analog meter on the load itself.

With two 60 watt light bulbs and a fully charged battery, the ammeter reads around 400 milliamps.

I didn't check the meter against my digital multimeter, but 400 milliamps is about right based on my full charge/discharge cycles I performed a few weeks ago.

The car is still running great, by the way. The IMA works like a charm. This is a great project for anyone who wants to do some home maintenance on their Insight's battery.

- Park

 

[Edward Dawes]

Whoops. Discharge #2 turned into a deep discharge on accident.

INSIGHT CHARGE - Citrus/Silver

May 2022 DATE / TIME,VOLTS,AMPS,TEMP (F),NOTES,amps * 100,D(isharge)/C(harge) + R(est) chart length in columns = (hours / 4) + 1 5/2/2022 9:50:00,157.8,0.342,46,REST,34.2 5/2/2022 9:50:00,159.1,0.339,46,CHARGE,33.9 5/2/2022 11:06:00,163.3,0.344,47,34.4 5/2/2022 12:17:00,166.3,0.342,49,34.2 5/2/2...

docs.google.com

I left the discharge process in the care of my brilliant grad student daughter. She dutifully logged data all day, and I showed her how to use the pull-chain switch on the discharge load to turn off the lights and change to 25W bulbs when the voltage hit 120V.

The battery lingered for a loonng time over or close to 140V, then tipped over a cliff. In one 85 minute interval, it dropped from 136.5 to 128.2V. In the next 76 minute interval it fell from 128.2 to 30.22V.

At that point my daughter called me for advice. I told her to turn off the light bulbs. Unfortunately, she turned off the grid charger instead of the pull-chain on the discharge load. So over the next 69 minutes the battery dropped from 30.22 to 8.4V, and did so without a cooling fan. Ouch. At least the discharge current was fairly low, and my garage is pretty cool.

So far the battery is recovering well on charge #3.

The good news is that it looks like my battery can hold a nice long steady discharge at a pretty consistent 140V+.

Onward...

- Park

I noticed on my first discharge, it took 2 hours to go from 144 to 130, then only 30 min down to 120 volts..... yeah...falling off a cliff is a good description....

 

[Jonny69]

Great thread. I can’t remember why I only skimmed through this before, maybe because it was before my first battery charging and cycling and I didn’t understand everything here. This thread deserves more replies.

So, as you’ve found, the voltage drops very quickly around the 140V point and it’s difficult to catch it at the desired voltage when you’re discharging manually. It’s a lot of checking. This is why I started the Simple Arduino Discharger project so you could connect it up and walk away. I reckon if you’re competent enough to build an OlRowdy grid charger you’ll be competent enough to to build a SAD discharge controller.

I’m also still of the opinion that the first discharge on a badly out of balance pack should only be to 140V. Maybe even higher on a pack triggering the IMA light. The logging from my first SAD discharge showed that the first cells were dropping out at this point. Despite opinions on here, I don’t like holding cells reversed, even at low current. If you were to shut off the discharge at this point, fully recharge and repeat, the next discharge will be a lot cleaner and much more even throughout the pack. This is because you’ll have significantly improved the performance of the weakest cells in the pack by reversing the memory effect and at least boosted the performance of the ones following closely behind them.

 

[MparkH]

I reckon if you’re competent enough to build an OlRowdy grid charger you’ll be competent enough to to build a SAD discharge controller.

Thanks! I remember seeing your posts when you were starting the Arduino discharger project. Glad to see you finished it...

DIY Simple Arduino Discharger for IMA battery

Here are some components I've used that will help the DIY builder. You'll find all these on eBay. As with most things on eBay, if you can wait for the long delivery time from China, everything is cheaper. A genuine Arduino "Genuino" Uno will be about £15. Chinese Arduino Uno clones can be had...

www.insightcentral.net

I absolutely would be interested in building it. What would be helpful would be a finished circuit diagram and list of parts. I’m more of a “mechanic” when it comes to electrical stuff - I can follow directions well but don’t grasp much of the theory.

- Park

 

[olrowdy01]

Thanks! I remember seeing your posts when you were starting the Arduino discharger project. Glad to see you finished it...

DIY Simple Arduino Discharger for IMA battery

Here are some components I've used that will help the DIY builder. You'll find all these on eBay. As with most things on eBay, if you can wait for the long delivery time from China, everything is cheaper. A genuine Arduino "Genuino" Uno will be about £15. Chinese Arduino Uno clones can be had...

www.insightcentral.net

I absolutely would be interested in building it. What would be helpful would be a finished circuit diagram and list of parts. I’m more of a “mechanic” when it comes to electrical stuff - I can follow directions well but don’t grasp much of the theory.

- Park

Lately some of us have been slow discharging to zero volts and even leaving the battery overnight with the light bulb load on it.

A few months ago I was talking to the owner of an aircraft battery maintenance business and he said he discharges Ni-Mh aircraft batteries to zero volts and leaves a dead short on them over night. I would not go to that extreme though.

My last discharge on my 8 year old Honda warranty replacement IMA battery was a grid charge & single discharge to zero volts and left overnight with the load connected. After a final grid charge the battery is definitely acting better than with a discharge to 12 volts.

So I'm not so sure partial discharges are the way to go with Insight batteries.

 

[catadarius]

Hi all

Will this charger work with an 2010 Insight?

I think I can do this project.


Inviato dal mio Mi A2 utilizzando Tapatalk

 

[MparkH]

Hi all

Will this charger work with an 2010 Insight?

Catadarius, apologies for the slow response. I don’t actually know the answer to your question. I have no experience with the newer Insights. But I would not be surprised if it worked.

- Park

 

[MaHiHy]

Hi Insight People,
I have an 08 Toyota Highlander and I want to accomplish the same thing with an appropriate power supply to reach 360 V which I've found. My question is: Does the circuit depend on the batteries to limit the high voltage to the maximum, in my case 360v, much like a zener diode or will the charger overcharge the batteries to a higher voltage? There is no voltage limiter on these Mean Well supplies.
Thanks

 

[olrowdy01]

Hi Insight People,
I have an 08 Toyota Highlander and I want to accomplish the same thing with an appropriate power supply to reach 360 V which I've found.

Please give us the supply name and part number you found.

My question is: Does the circuit depend on the batteries to limit the high voltage to the maximum, in my case 360v, much like a zener diode or will the charger overcharge the batteries to a higher voltage? There is no voltage limiter on these Mean Well supplies.
Thanks

I know nothing about the Toyota's battery system (or the cooling fan voltage etc requirements).

Good storage batteries will normally charge to some fully charged voltage and try to limit further voltage rise. BUT the battery(s) will also start dissipating the heat generated by the overcharge and can (in extreme cases [think of the exploding hover boards!]) vent, explode and or start fires. Depending upon the batteries chemistry, some lithium batteries can be ruined by over voltage charging and too low a discharge voltage.

Part of the apparent higher battery pack charged voltage will be the internal resistance of the pack's cells and wiring due to the charging current and ambient temperature.

 

[MaHiHy]

This cc power supply doesn't have an adjustable voltage limiter. I think you happened to find one that has the same voltage limit as your battery, about 175V. This one will go to 400 V in its safe operating area. I can add a simple voltage regulator that won't kick in until the output goes above 360 volts, the upper limit of my battery. The Prolong for my HiHy has a voltage limit of 360, same as the battery so it is a bit more sophisticated.

So what do you all do when your battery is fully charged? It doesn't appear there is an auto shut off in the DIY design. So how long are you comfortable running charging current through a fully charged battery, or to be more precise, how long is the battery comfortable??

The one I'm looking at is the Mean Well HLG-185H C500 which can be adjusted for constant current of 350 ma and is rated at 200W. I calculated my battery needs 216 watts. Probably close enough. I have not bought it yet.

I may have just answered my own question but I wanted to know what you folks are doing.
And thanks for the reply.

 

[olrowdy01]

Sorry to hijack the thread guys. This ought to be pulled out to a new thread.

This cc power supply doesn't have an adjustable voltage limiter. I think you happened to find one that has the same voltage limit as your battery, about 175V.

The max voltage of my V2 DIY supply is 200 volts.

This one will go to 400 V in its safe operating area. I can add a simple voltage regulator that won't kick in until the output goes above 360 volts, the upper limit of my battery.

Probably not necessary, depending upon your battery chemistry and it's end of charge characteristics.

The Prolong for my HiHy has a voltage limit of 360, same as the battery so it is a bit more sophisticated.

Will it charge your battery OK?

So what do you all do when your battery is fully charged? It doesn't appear there is an auto shut off in the DIY design. So how long are you comfortable running charging current through a fully charged battery, or to be more precise, how long is the battery comfortable??

We charge for 24 to 30 hours or a little longer until we see (hopefully) 174 volts at ~350 ma. With a good battery above ~170 volts the battery voltage rises ~2/10 of a volt per HOUR! The slow rise in voltage gives us plenty of time to stop the charge with the simple grid charger.

The one I'm looking at is the Mean Well HLG-185H C500 which can be adjusted for constant current of 350 ma and is rated at 200W. I calculated my battery needs 216 watts. Probably close enough. I have not bought it yet.

If your battery tops out at ~360 volts and the supply is putting out 1/2 A the supply will be delivering 180+ watts. You ought to use a good air flow fan on the charger itself. My V2 supply at 100% SOC is outputting ~60 watts and runs at the cabin ambient temperature with a small computer fan for cooling it.

I may have just answered my own question but I wanted to know what you folks are doing.
And thanks for the reply.

See more details of my V2 DIY charger by going to my website. The link can be found by clicking on the 'CRX'' area below this post.

Out of curiosity, how many digits does your Prolong charger meter have?

 

[MaHiHy]

You're just the guy I want to talk with. Thank you for getting into this. I posted on this thread because I thought you might still be monitoring it.

I don't have a Prolong. I am reverse engineering this thing from the specs I see on the Prolong website and your plans. The only difference between our batteries is probably the voltage and current ratings.

From the Prolong Website
The Prolong pro charger has a 3 digit meter. "ProlongPro Battery Charger – Will fully charge a NiMh hybrid batteries pack in 1-3 hours – Works with all common NiMh battery sizes up to 240 cells – User selectable charge/balance mode vs. charge only (PHEV) modes.- User programmable cell balancing time – Compatible with all Prolong Car Harnesses – Audible alert when finished to minimize shop idle time – Reverse polarity protection to prevent system damage from incorrect battery connection – Thermal protection to prevent against excess heat damage ProlongPro Battery System User Manual"

That tells me charging current can be a lot higher. Maybe we're pussy footing around at 350 ma?? Or is 350ma required for cell balancing? 350ma seems to be the current from the round hocky-puck version of the Prolong

Thanks again.
G

 

[olrowdy01]

You're just the guy I want to talk with. Thank you for getting into this. I posted on this thread because I thought you might still be monitoring it.

I don't have a Prolong. I am reverse engineering this thing from the specs I see on the Prolong website and your plans. The only difference between our batteries is probably the voltage and current ratings.

After reading up on the Ni-Mh battery that your car seems to use,
In affect all you have to do is set the supply voltage to be (perhaps) 10 volts above the 100% full charge rating of your hybrid battery and use 350 ma charge current. I don't know what power source your battery cooling fan uses, so that's left up to the student.

quote]From the Prolong Website
The Prolong pro charger has a 3 digit meter.[/quote]

That isn't going to show the 1/10s of a volt change above the charge creep voltage point.

"ProlongPro Battery Charger – Will fully charge a NiMh hybrid batteries pack in 1-3 hours – Works with all common NiMh battery sizes up to 240 cells"

One hour to balance charge a Ni-Mh battery !?!

– User selectable charge/balance mode vs. charge only (PHEV) modes.- User programmable cell balancing time – Compatible with all Prolong Car Harnesses – Audible alert when finished to minimize shop idle time – Reverse polarity protection to prevent system damage from incorrect battery connection – Thermal protection to prevent against excess heat damage ProlongPro Battery System User Manual"

That tells me charging current can be a lot higher. Maybe we're pussy footing around at 350 ma?? Or is 350ma required for cell balancing? 350ma seems to be the current from the round hocky-puck version of the Prolong

Thanks again.
G

There was a lot of testing done years ago by Mike Debrosky(spelling?) that involved various charge/discharge rates for deteriorated cells etc. He settled on 350 ma charge/discharge rate that was safe for our IMA batteries. The info is still on his website.

I bow to Mike's research and will stick to a slow charge of 24 to 35 hours at 350 ma. [edit to time to charge 5/26/2022 ]

Chemical reactions can take time to happen. I've found that you should keep the IMA cooling fan running all the time while cycling the battery. There's lots of heat being radiated for many hours after a 350 ma charge to 100% SOC.

I use two light bulbs at the start of the discharge at ~350 ma discharge rate. The discharge current automatically tapers off as the battery voltage gets lower. This relieves the stress on the reverse charged weak cells. I do a complete [slow] discharge to 0 volts in one step. When the discharge current gets very low, I change the load to use one bulb and leave it on the battery overnight.

My 9-1/2 year old Honda warranty replacement battery is still working fine for my driving style. Yes several of the cells have low capacity but they still work OK.

 

[MaHiHy]

Thank you for your "Insight", olrowdy01!

The Prolong puck is a 350 ma charger, probably to avoid battery damage. It has a 12 V output for the fans. I just have to figure out the right connector to hook up the fans.

As I say the charge voltage isn't settable, so I can add a transistor voltage follower to limit the voltage out. I'll have to heat sink it. It should only have to dissipate 10-12 watts.

As for the battery, not only is there the chemistry to deal with but there is charge migration which is why the battery no load voltage can rebound to over 100 volts after a discharge. The migration is slow in both directions, I would assume.
I have a few voltmeters & ammeters that have 4 digits so no problem there. They're also dirt cheap online.

If you have a link to the bat testing by Mike Debrovsky could you send that along? Thanks.

As far as I can tell I have the original battery. My Dr. Prius app is showing a rise over the last year on internal cell resistance, now up to 35 milliohms and is operating at about 60%, so that's why I want to do this. It's a very useful app, I also recommend Blue Driver app which costs some $ but gets codes that a regular OBDII reader can't access, like speed sensor and CPU communication errors. At least for the Toyota hybrids. It's made trouble shooting a breeze so far.

I've been riding without the 5 rear seats for the last year. When I got the HiHy it was missing rear under bumper chassis plugs and filled up with water in a heavy rain. The water got into the battery and caused HV leakage to the chassis. They HiHy has a detector for that and shuts it down. So I had to take it apart, plugged the leaks and left a fan in the car for a few days to dry out the battery and rugs. Also had a bad connector that caused a fault code so I cleaned all the com connectors in the battery case to cure that. That said, I put the battery cover back but left it accessible just to wire up a charger. I also get 1 mpg better mileage not hauling the extra weight of rear seats. I'm a jazz bassist so I'm usually just carrying my bass and amp around. It's more like a truck for me.

As for the discharge light bulbs, the resistance drops as the voltage drops but not enough to make them a constant current load. But it's a cheap, no hassle way to discharge the battery.

So I guess I'm ready to get this gizmo going. I thank you for all your time and help and posting your schematic. My background is designing and modifying hi end vacuum tube audio amps so 360 volts isn't scary but is to be respected. If it's of any use to you I can post my version of your version. I not planning to build a fancy box, just maybe breadboard it with a fan and some jacks to hook up meters.

I just went through having Covid for 5 days so I thank all the scientists that figured out how to make a vaccine and drugs to fight it in record time. If I had gotten it before vaccines I might not be here today. I'm 70 and it was just like having the flu. So please stay safe, however you do that. This latest variant is highly contagious.

-G

 

[olrowdy01]

Thank you for your "Insight", olrowdy01!

The Prolong puck is a 350 ma charger, probably to avoid battery damage. It has a 12 V output for the fans. I just have to figure out the right connector to hook up the fans.

As I say the charge voltage isn't settable, so I can add a transistor voltage follower to limit the voltage out. I'll have to heat sink it. It should only have to dissipate 10-12 watts.

Why are you worrying about the max power supply voltage (400 volts) being more than the battery will allow at 350 ma (your posted number, 360 volts at full charge)?

If your Ni-Mh battery responds near the end of charge similar to the Insight battery, (2/10 volt change/hour) all you have to do is turn (or program) the charge power supply OFF when the 100% SOC point occurs.

Believe me, we don't know absolutely for sure when the Insight packs are 100% charged either. We have educated guesses, but the battery voltage varies with temperature, IR etc etc as to when 100% SOC has been reached.

And to top it off, the Insight discharges the SOC down (into some load) to ~80% when you next use the car. The Insight runs the IMA pack from 20% to 80%, not 100% SOC.

[snip]

If you have a link to the bat testing by Mike Debrovsky could you send that along? Thanks.
-G

I did a quick forum search for Mike's website. All I can find in his forum posts is his email address. I also did a quick search on the web, but no luck finding his website either. Perhaps if you send him an email he will point you to his site.

[snip]

As for the discharge light bulbs, the resistance drops as the voltage drops but not enough to make them a constant
current load. But it's a cheap, no hassle way to discharge the battery.

I don't want a constant current discharge load. I am trying to simulate a pack long term self discharge. As the battery voltage goes down, the bulbs change the [effective] load.

I have a chart on my website that shows the current change effect of different wattage light bulbs vs the battery pack voltage.

 

[MaHiHy]

"Why are you worrying about the max power supply voltage (400 volts) being more than the battery will allow at 350 ma (your posted number, 360 volts at full charge)?"

I'm not familiar enough to know how much and for how long over voltage can damage a battery. It would be a giant PITA if I have to fix it unnecessarily. The Prolong chargers have a maximum V output = to the voltage of the intended battery, 360 V for my HiHy. So they see fit to limit the voltage. So that raises my concern. Obviously you are getting good results with your setup.

"And to top it off, the Insight discharges the SOC down (into some load) to ~80% when you next use the car. The Insight runs the IMA pack from 20% to 80%, not 100% SOC."

I assume my Toyota will do the same or just run until the SOC goes below 80%. My battery SOC is between 50-65% right now. So the on board computer doesn't give it much range due to its reduced performance.

About the bulbs - I'm not implying anything about what you may want or what is desirable, just commenting on how an incandescent bulb works. A cold 60 W bulb is 17.9 ohms, a hot one is 240 ohms.

Thanks again. Will check out your website again. I'm still getting over covid. My personal SOC is currently limited.

 

[olrowdy01]

"Why are you worrying about the max power supply voltage (400 volts) being more than the battery will allow at 350 ma (your posted number, 360 volts at full charge)?"

I'm not familiar enough to know how much and for how long over voltage can damage a battery. It would be a giant PITA if I have to fix it unnecessarily. The Prolong chargers have a maximum V output = to the voltage of the intended battery, 360 V for my HiHy. So they see fit to limit the voltage. So that raises my concern. Obviously you are getting good results with your setup.

I think you are misunderstanding what the max unloaded voltage of the supply is about. I'm sure you know that to charge any kind of rechargeable battery the charger has to be able output at least a little more (and sometimes even a lot more) voltage than what the charged voltage of the battery will end up being.

In your case the 400 volts represents the absolute max battery voltage the supply is capable of charging

As long as none of your cells are completely open you will never see 400 volts while charging your battery. The battery in affect loads your power supply enough to set the constant current to 350 ma at the voltage that the battery is at the time.

Assuming your Ni-Mh pack responds to a charge like the Insight pack does, here's is what should happen when doing a charge.

When the charger is first connected, and then turned ON, the power supply voltage will start charging at whatever voltage your battery is at (just guessing here, maybe 330 volts) and will output the constant current of 350 ma while charging. The voltage will quickly rise to some newer value (still below 360 volts). After an hour or so the voltage rise per hour will start to slow down. Eventually (after going through the 2/10s volt per hour stage) the battery will be charged to 360 volts but the charge will continue at 350 ma and ~360 volts (never at 400 volts). The supply and battery will both be dissipating a lot of heat though if the charge continues.

It's been recommended on the forum to make sure all the cells are fully charged to 100% SOC, to continue the charge for another few hours.

After you get the charger working, record the pack voltage every 1/2 hr for awhile and then every hour to really see what is going on.

About the bulbs - I'm not implying anything about what you may want or what is desirable, just commenting on how an incandescent bulb works. A cold 60 W bulb is 17.9 ohms, a hot one is 240 ohms.

No problem. I just wanted to explain why I like bulbs as the load.

Thanks again. Will check out your website again. I'm still getting over covid. My personal SOC is currently limited.

Get well and be carefull my friend.