maanantai 24. marraskuuta 2014

Winter update

That's 3.7˚C

It's been a little slow on the blog side, but in the real life I've been driving both of our electric cars regularly. Even exclusively, since I sold my diesel car and we're now all electric with two cars and a motorcycle. Hooray!

The DIY car got a little winter update in the form of a cabin heater, which I bolted on to the side of the battery box in the trunk. It gently heats up the aluminum box with the cells inside, but mostly the cabin of the vehicle. The little thermometer has it's sensor inside the box, in the middle of the pack and between the cells. It really hasn't shown temperatures below zero yet, since both charging and driving seem to keep the cells well heated. Instead I've seen temperatures close to 30˚C even with the outside temps hovering around or slightly below freezing. Currently the car has no batteries in the front that would need heating, so the single PTC heater takes care of everything.

With no batteries in the front of the vehicle, it should not come as a huge suprise that even though I bought some studded winter tires, they don't grip very well in the front. It could also be that they are "Aurora" branded tires, which are hardly recommended. Should get me through the winter though. 

Also in the picture behind the big charger is a smaller, grey 12V charger. My 12V AUX battery hasn't  been very happy with just the occasional 13.5 volts it gets from the DC/DC converter while driving, so I installed an automatic lead battery charger to keep it charged at all times. It's connected to the same 230VAC input as the main traction pack charger, so it automatically charges the AUX battery whenever the main battery is charging. Quite like the C-Zero, where the DC/DC converter also is always on while charging.

The car has two 230VAC plugs in the rear, which means that I can choose between heating and charging simply by choosing which plug to plug in to.

As for the C-Zero, it's also working great. I installed a Binar ethanol burning 5kW heater to keep it usable over the winter as well and also a 230VAC plug for a electric cabin heater. It's been a great vehicle and fun to drive. The only thing I'm really missing is Cruise Control. It would make keeping a steady economical speed a lot easier than it is now.

sunnuntai 5. lokakuuta 2014

Baby got home

So I got our new baby home, finally. They had fixed the dents in the roof and repainted the whole roof. I'll have to make sure they did the brake vacuum pump recall or take it back for them to do that when they get the part. It had to be ordered from France.

So what happens when you get a new vehicle? Well, you start to think about ways to improve it, of course. So far I've acquired some Calix heating gear in order to pre-heat the car before driving. I'll just need to decide where I want to put the heater within the car. More on that later.

keskiviikko 17. syyskuuta 2014


We decided to take the plunge and get a non-DIY electric vehicle as well. The main reason being that a store bought EV gives you the ability to quick charge. I figured that a black box EV is still better than a black box Diesel. At least you won't be burning the oil. And I honestly think that the EV should pay for itself. Since I got a really good deal on a 2011 Citroën C-Zero it might actually happen.

This'll be my gas station experience henceforth.

I took the car for a day of test driving. Did over 100 km and quick charged three times. It worked very well. Average consumption while doing 80-90 km/h behind a lorry on a freeway was about 128 Wh/km. Not bad. The car only has 10.000 km on it so it's practically new, even if it's a 2011. It had been the floor model that apparently nobody wanted. I'm not surprised, since the sticker price was over 30.000 euros. Fortunately I got it for less than half.

Good times.

sunnuntai 7. syyskuuta 2014


I'm going to come out and recommend some pack level monitoring, which will cut off your pack completely from anything else in certain conditions. At least if you're like me and leave your vehicle for over a week with the high voltage turned on and therefore both DC/DC converter charging your 12 volt aux battery and your controller charging it's caps all the time.

Maybe if I had been a little bit more careful when adding 8 new cells into the total of 29 cells in the motorcycle and bottom balanced all of them together instead of just driving the old cells empty and bottom balancing the new, I might not have almost a complete set of bloated 40 Ah cells. Maybe. Maybe I would have lost them anyway. Maybe I should have just been a little bit more careful.

If there's a good news somewhere in this it's that these LiFePO4 cells are safe. You can discharge them to death and get a little bloat, but that's all. The bloat won't break anything, unless you've done what some people rather cluelessly recommend, which is tying them together so they won't have any space to expand. Usually that's how you make bombs. I don't do bombs.

Anyway. At least I'll try to change the bike so that I can't repeat this stupid mistake and I think you should try to do the same. At least have everything behind the key switch. A master cutoff could be a good idea too, but then again you can just as easily forget to turn that off too. I've already done that in the car a few times. Luckily in the car the only thing that can drain the pack without the key in the lock is the pre-charge resistor, which takes a really long time to drain a battery.

I think I'll concentrate on the car again for the winter and see what I'll do about the motorcycle in the spring when it gets warm again. Perhaps we'll have the new CALB CAM cells widely available by then... or maybe even something better. One can always hope. I'd really like to make my weekly 238 km trip between Espoo and Pori on electric, but we're not there yet. Unless you can afford a Tesla.

Bloated cells trying to get some Lebensraum.

maanantai 11. elokuuta 2014

Belly pan is back on

I grudgingly cut a piece off of the original belly pan of the GPX. I did look for a second hand pan on ebay, but they were all in such a crappy condition that I didn't want to buy any of them. Which really didn't make it any easier to cut into the one I had, which was in really good condition. I did save the piece so I suppose I could mend it again, or at least use it as a mold, in case I need to.

Anyway. The cut-off is not too bad and looks alright. Makes the charger blend in quite nicely. I'll need to do some more work to make it fit perfectly, but at least it's back on now and looking just fine.

Drove to work and back again today. It takes about 9 Ah to drive the 12 km distance. So I could get to work and back two times before needing to charge, but I charged at both ends anyway. Looks like the charger isn't very interested in stopping the charge at all. It may be because if I have the Cycle Analyst and contactor engaged, I also have my PSU DC/DC converter connected, which sips a little bit at all times charging the tiny lead acid battery I have. It does keep the voltage at about 102.5 volts, so it won't really overcharge, and drops the amperage to near zero, but it's not doing any good either. I'll need to see if it ever quits with everything else turned off.

At the apartment the outlet at the parking lot has a fixed 2 hour timer, so the charge will stop after the allotted time in any case, which in this case is a good thing. Two hours is also just enough to charge from fully empty to full at 21 amps anyway. The charger starts ramping up the amps very smoothly, which should prevent any slow 10 amp fuses from blowing, even though it's drawing 11 amps at full power.

I suppose I could contact the seller if there's anything that could be done about this problem, which is clearly a fault in the programming, but I ordered the charger directly from China and on the cheap, so any chances of anything happening are rather slim. It's what you get for being cheap.

One more thing. The bike is really nice to ride. Acceleration is very nice once you get moving. Right off the line it still hesitates for a bit. Then it's all pure fun until 120 km/h. Which makes it really nice in highway traffic. Good times.

torstai 31. heinäkuuta 2014

Bike upgrade

I finally had a chance to install four more cells into the kWsaki electric motorcycle. Actually, take four old cells out and put eight new ones in. Good that I did, because taking out four of the old cells I found two of them slightly bloated and below acceptable voltage. The other one was below two and the other below one volt. Not happy cells.

Both were cells which I had earmarked for observation before, with letters "A" and "X". I also took out cells marked "B" and "D". I've only marked cells which have seemed dubious at some point, either for going high on recharge or low on full discharge. Hopefully I caught all bloated cells and none were left in, since I didn't really go through the rest of them. It's hard to say at which point these got damaged, but I'm hoping they just developed issues while I pushed the pack really low right before doing the swap. At least I didn't notice any issues before.

The other thing that I did was to attach the new 102V 21A charger to the belly of the bike. It looks just about as ghetto as can be and it rather is, but it works and it'll look prettier once I modify the belly pan to fit back on. In any case, the charger works and charged the battery from the new empty voltage of 83.8V, which is just a hair above my previous fully charged voltage, to 102 volts and bit over it. Strangely it wouldn't stop charging even when the Cycle Analyst registered a charge current of less than one amp. The highest voltage I noticed was 102.5 volts. I suppose it would stop at some point. The measurement at such low levels is not very accurate and the little laptop PSU doubling as a DC/DC converter was also running, which may make a difference as well.

When I pulled the plug, 39 amp hours had gone in to the pack. Just one amp less than rated capacity. I think this is a good results, since most of the cells are now over two years old and I'm not charging them fully anyway. The next morning the pack had settled to a total voltage of 97.8 V. I'll have to get used to that number now.

I also got to do a little test drive with the new pack. I have to say that the bike felt better than ever. Even with the added weight of four more cells and the rather big TCCH/Elcon 2.5 kW charger, acceleration was brisk and it just felt very peppy. Especially so on the freeway, where the speed would start to run out at 100 km/h, it now did so around 120 km/h instead. I managed a new top speed record of 128 km/h. Up from the previous 110 km/h or so. In other words just a little faster than you are allowed to drive anywhere in Finland, so I think it'll be plenty.

The Kelly controller I now have in the bike seems to be also doing thing a bit differently from the Alltrax AXE I had in before. Where the AXE would suck amps probably as much as it would put into the motor, the Kelly pulls a lot less. Even with the 600A controller set to 85% output, or 510 amps, it had only taken up to 200 amps from the pack. This was during the test drive I did the new speed record with, so it definitely was putting everything it was allowed to into the motor. In any case, it's much better this way, so I'm not complaining. The batteries can take it a little easier and I still get full power.

perjantai 25. heinäkuuta 2014

Adventures in Tireland

The rims that were too good to be true.

So I got those rims from a Peugeot 307, the same car I use for long distance travelling, and purchased 195/65R15 Michelin Energy Savers for them. They seemed quite nice under the kWsara and were dead silent, but alas, it was not meant to be. Hitting a bump made a nasty sound and in the end I just had to back off and get 175/65R14 tires for the original 14" steel rims. They didn't have Michelins in that size, so I chose Continental Premium Contact 5s. They're not quite as quiet, but still a lot quieter than whatever old tires I had on previously.

I'll use the Energy Savers on the alloy rims in my 307 probably next summer, when my current Nokian Hakka Greens are probably starting to run out, so it's not a real loss to have those two sets around.

I just can't emphasize enough how quiet the Michelin Energy Savers are. Definitely my go-to tire as of now.

perjantai 11. heinäkuuta 2014

New charger for kWsaki

Yesterday, I finally got the new charger for the kWsaki. DHL and their local agent tried to make it as complicated as possible, but finally I just drove to their warehouse at 17.20 on a Friday and picked the damn shipment myself. Luckily they were still there. I think I'll specify pickup from there now on.

In the usual fashion, the charger was very lightly packaged and once again came in a little damaged. This time it was one of the cooling fins. Shouldn't be a problem, though. It's a little bigger than I thought, but I still believe I should be able to fit it under the frame and within the bottom fairing.

The charger seems to have been correctly configured, at least according to the sticker. It says 28 cells, but I'll use 29 instead. I just didn't want to complicate their life by specifying anything out of the ordinary. 102 volts divided between 29 cells comes down to about 3.52 volts per cell. The charger, charging at 21 amps, should fill my 40 Ah cells in about two hours, while using 11 amps at 230 VAC.

Look! It came with instructions too! "Connet black and red wire together to start automatic control." Yes, that was the only documentation in the package. In that box there was the control cable which the comprehensive documentation refers to and an additional Anderson connector. Most likely I'll just leave the Anderson connectors out, because they're mostly just asking for trouble.

tiistai 8. heinäkuuta 2014

Regarding temperatures

While doing the battery test drive for the previous post we also had the hottest day of the summer so far. Temperatures were around 28 degrees Celsius. Very hot for these parts. Just last week we had more than 10 degrees less, albeit it was particularly cold then.

After driving the battery empty in two 30+30 minute drives, with about 30 minutes in between, both the motor casing and the controller case showed an external temperature of around 60 degress Celsius. Rather hot, but the motor is rated for 80 degrees and the controller starts throttling gradually at 85 degress Celsius, so not a problem. I didn't notice the controller throttling while driving. I did curse myself for not logging it's data though. It would have been interesting.

The DC/DC converter wasn't really even warm, but the aluminum sheet that both the controller and the converter are attached to did show temperatures close to 50 degrees, so it was working as a heatsink as planned.

As for the batteries, in their closed and rather insulated case, were also noticeably warm to the touch. My infrared meter showed them at around 50 degrees. Kind of approaching uncomfortable zone, but not reaching it. I did however check how the temperature reacted while charging. It didn't go up, but instead came down to 45 degrees rather quickly and I didn't notice it going back up. All good then.

Ambiguity of energy consumption

Yesterday I took it upon myself to see just how far I could get with just the single set of 60Ah CALB SE cells that I currently have in the car. That part of the equation is rather clear. It's 25 kilometers or a little over 15 miles. How much energy was used, now that's a different question altogether.

I did measure the amount of energy used by the charger to charge the pack from quite empty to 87.6 volts or 3.5 volts per cell, with a CC/CV charge pattern. The result came in at 5.8 kWh. Now I don't know how accurate my cheap watt meter is, but if we assume it's anywhere near the thruth, the mileage from the wall was 232 Wh/km. Not bad, considering it was mixed city driving and no regen.

I suppose that's actually the most realistic way of measurement. After all, it determines how much you'll end up paying for your kilometers. That comes down to a little over 2 cents per km with our electricity prices, by the way. Or 2,32€ per 100km.

Nevertheless, it would be nice to know how much the actual driving uses. If we assume 90% efficiency in charging, we get 5220 Wh. Or about 209 Wh/km. Even better. The pack should however contain about 4800 Wh, or 60 Ah times 80 volts. That way the result is 192 Wh/km.

My Cycle Analyst however sees things quite differently. It measured 62.6 Ah into the pack and 87.8 Ah out while driving. It's obviously not counting the Coulombs quite correctly. I'll have to try and figure out why that is and make the numbers match. For now, I know I can drive the car quite a bit further than the Cycle Analyst numbers would indicate.

As for the range, the 25 km for a 25 cell pack of 60 Ah cells is pretty much dead on for what I had guesstimated beforehand. Doubling the cell count should double the range and give me the 50 km I had in mind originally. That's about 80 € per kilometer in battery cost with these cells.

keskiviikko 2. heinäkuuta 2014

Live for speed

Well, some speed at least. I did a little top speed test with the kWsara a couple weeks back. It was raining cats and dogs, so the circumstances were far from perfect. Nevertheless, I reached a top speed of 84 km/h (or 52 mph) on fifth gear while consuming approximately 22 kW. Not a whole lot, but rather predictable though.

The car was a petrol model, which revved several thousand rpm, so the gearbox has rather low gearing for the electric motor, which only likes to rev 2000-3000 rpm. So when 1000 rpm equals about 35 km/h on the fifth gear, you end up with less than 90 km/h at 2500 rpm. Other factors include voltage sag, which may have an effect since I still only have single set of 60 Ah cells in, and the tires, which are now the stock 185/65R14.

I'll get more cells before long to keep the voltage as high as it can be and I also just today picked up these 15" rims. They're meant for a Peugeot 307, just like my daily driver, but should also fit the Xsara. Both vehicles are from the same parent company, PSA, anyway. I'll get 185/65R15 or 195/65R15 tires for them at some point. That should increase the top speed by some 10-15% as well.

I know, the rims have the Peugeot lion on them, instead of the Citroën logo, but as I said, they are made by the same company. Also I don't really care.

For a bigger increase in top speed I'd have to spring for a transmission from a diesel model, but changing transmissions... Well, not my cup of tea.

perjantai 27. kesäkuuta 2014

Better, yes?

I improved the Air Intake Filtering System (AIFS, as I like to casually call it) a little bit. Still not the prettiest thing on the planet, but a little less protruding at least. I'll try to fix it a little more permanently once I have the new cells in.

On that note I have eight new CALB SE40AHA cells ready to rock. I noticed they have new cool vents with a little round cap on them that says CALB. I'll be sure to put these cells in the motorcycle so that they'll be the most visible ones. As for the bottom balancing, taking place here in the picture, I set my Professional Bottom Balancing Tool (or PBBT) to 2.7 volts, so the cells drained in parallel to 2.69 volts. The next day after disconnecting them from everything, including each other, they were at exactly 2.71 volts each. Shows that doing this in parallel works, all cells are good (bad cells would go down by themselves) and they are quite identical in all intents and purposes.

lauantai 14. kesäkuuta 2014

Temporary solution


I came up with a temporary solution to the air filter sticking out. The tube still sticks out almost as much, but... Well, I think it's a little better. I'll have to take the whole thing to my underground lair a little later for a proper fix. I'll try to include the electric fan in there then as well.

perjantai 13. kesäkuuta 2014

Sticking out

Ok. I suppose it sticks out... a little.

Air cleaner and water intake prevention

Since it's been raining cats and dogs for a few days and preventing me from driving the bike to work I got anxious to do something about the waterproofing of the DC motor in the kWsaki. Here's what I've come up with.

The tower consists of Biltema part numbers 88463 (hidden inside), 32323 (air filter) and 88471. I have an 8" fan which I'm also planning to put inside the big adapter piece, so that the motor will always have more than enough airflow, even at low rpm. I just don't have the fan with me right now. Pictures of the installation later.

Update: If you're wondering what this has to do with waterproofing, my thinking is that adding the filter and moving it a little further away would mean less water in the motor. Water entering the filter at standstill should also not find it's way inside the motor nearly as much as it does now. This setup also gives me the option of moving the intake filter somewhere else using some flexible tube.

tiistai 10. kesäkuuta 2014

Energy Day 2014 in Pori

There we were. My EVs next to a Tesla. Quite a few of people stopping by and asking a lot of questions. I think my DIY projects gathered more interest than the Model S. It is just an OEM car anyway.

Well, at least there were a lot of people until it started pouring. During the rain, not so much.

I can't say I couldn't some use for one. Looks smaller than it is, really. I'd need mine with all 7 seats.

Something interesting I noticed. Rust. I've heard that the attention to detail is good compared to it's other countrymen, but I suppose an american car is still an american car. Not cool.

kWsaki updated and running again

With the Energy Day coming up it was time to get the good ole kWsaki back into running condition. I had neglected it and scavenged parts from it for the car. It had lost it's AXE7245 controller, so it was time to give it the Kelly KDH12600D controller I had originally meant for the car, but the AXE had some features I needed there. Such as 0-5V throttle input, which the cheapo model Kelly doesn't have. It only supports 2-wire pot, which the Magura twist grip throttle in the motorcycle has anyway. 

The KDH12600D could go up to 136 volts and 600 amps, but it may not be a good idea to go so high. In any case I moved two SE40AHA cells away from the top row to make the front wheel clear a little better and made a place for five more cells for a total of seven cells in the bottom row. Not really a row, since it's four cells parallel to each other and two adjecent. That means there's now space for four more cells in the top row. That makes 29 cells in total for the whole vehicle and a "nominal" voltage of 84 V. That's actually 92.8 V with 3.2 V per cell, 102.2 V charge voltage and I'm expecting to see 96.7 volts after charging. Should give a bit more range and perhaps a way to reach highway speeds too.

When I had both 60 Ah and 40 Ah packs in parallel in the car, there was a problem that two of the 40 Ah cells were shooting to over 4 volts way before the others reached even nearly full state of charge. I didn't know whether this was because of this parallel setup or not. Now that I took the 40 Ah cells out and charged them alone, the same cells were hitting voltages around 4.5 volts. Scary zone, that is. It does however mean that parallel charging uneven packs may be just fine, just as I thought. Those two cells just have dimished capacity compared to the others, so I put in an order for 8 new SE40AHA cells to replace those two and a couple more cells to get the 29 cell pack together. I'll have 4 cells left over, at least two with lower capacity, but still a probably quite usable 12 volt pack, perhaps for the car or just for my test bench.

Kelly KDH12600D installed. The rusty bits got treated with some black paint.

lauantai 24. toukokuuta 2014

Driving about

We've been driving about in the EV for a few days. Just short trips to parents-in-law's for Sauna and flea market in the 6th city district. Mainly because I a bit of an issue with flywheel balance. I'll probably try to get hold of a another compatible flywheel and have a new adapter made specifically for that and have them spin balance the whole thing as one. That should give me a little bit smoother ride.

It's still already cool to drive about in a almost zero carbon way (we currently buy hydroelectric power) and hear all the noises around you while being dead silent at stops. Not bad, not bad at all.

The additional fourth support arm of the electric motor drivetrain that I just added seems to be working perfectly and stops the motor from rocking backand forth violently. It'll be shortened and all prettied up... someday.

tiistai 20. toukokuuta 2014

Got rims

I got myself some retro rims today. They need quite a bit of work to look all shiny and pretty, but I got a good deal on them. Whether they'll ever look pretty depends on the eye of the beholder, I suppose, but they suited my sense of whimsy, as Jack Rickard likes to say. They don't seem too bad aerodynamically. At least compared to a lot of rims out there. I'm pretty sure they'll fit into the Xsara, but I'm not a 100% sure. I guess we'll find out soon enough.

torstai 15. toukokuuta 2014

Energiapäivä 2014 Pori

I promised to bring a handmade EV or two to this Sustainable Energy Fair on 7th of June in Pori.

Faith in the system

Some faith in the system was restored today. Trafi had sent the vehicle tax information and to my great surprise they had done the right thing after all and decided to tax the vehicle based on zero emissions! The alternative would have been to tax it based on weight, which is the default for pre-2001 vehicles under 2500 kg.

Actually I now noticed that it actually says so on the Trafi web page:

Autojen, joiden ainoa käyttövoima on sähkö, perusvero määräytyy päästötiedon 0 g/km mukaan.
I hadn't noticed that before and obviously the person I asked this about earlier hadn't either.

The downside is that electric-only vehicles are blessed with a separate tax to counter the fact that they don't use any heavily taxed gasoline. That amounts to 0,255 cents per day for this vehicle, while the base tax is 0,118 per day. 136,14 € total per year.

In any case, at least I'm not getting any extra punishment for converting such an old vehicle. As a bonus I'll save some money in the yearly inspection, since the vehicle needs no emissions tests.

keskiviikko 14. toukokuuta 2014

The downside of torque

Well. Turns out what was fine for mounting a relatively huge 1.8 liter petrol engine doesn't seem to work out too well for mounting a tiny electric motor with gobs and gobs of torque.

After a bit of repair work on the motor mounts and making one of the mounting arms out of 25mm or 1 inch steel tube, the non-hollow type, I proceeded to test the car a little. It all ended quite abruptly with a bang and a gear stick that moves back and forth quite freely, but sideways not at all.

I'm really not converting another car with a transverse engine. Ever.

I didn't have time to look into it. I hope the gear shifter has just dislodged itself from whatever it is supposed to be lodged into. I suppose the worst case scenario is that the transmission is stuck into third gear forever. Not that it's a bad gear to be in. Just that reverse is kind of useful too.

I've come to the conclusion that I need another mount point. Currently the transmission plus motor is mounted to the vehicle at three points. Above the transmission on the driver's side, at the end and quite high above the motor at the other side and at the drive shaft of the right front wheel. This setup seems to leave quite a lot of room for the motor to rock back and forth in the engine bay, which results in all kinds of nasty stuff. The sheer mass of the petrol engine must have kept it at bay originally.

I'm thinking of adding a sort of a torque arm from the motor adapter plate to directly towards either the rear or the front of the car, with a rubber mount at the vehicle side. It's the only way I've come up with so far to stop the damn thing floating about. We'll see what I end up with.

I wonder, which is worse, having a working vehicle which you can't drive on the road, or a vehicle which you could drive on the road, but can't because it's broken?

tiistai 13. toukokuuta 2014

kWsara inspected and street legal

Yesterday was the day. 

I set off to the inspection with 172179 km in the odometer.

It was a little rainy, but no matter.

After everything got inspected and even the regular yearly inspection passed, to my no small surprise, we proceeded to weight the vehicle.

I was prepared to lose a seat due to gained weight, but it was not to be.

The front showed 674 kg and rear 448 kg. Those two plus a 75 kg driver equals 1197 kg! Only 7 kg more than original curb weight. I couldn't have done better even if had carefully measured everything.

So no seats were lost and all was good. I even stayed below 1200 kg, which means I'll save on taxes, which are calculated based on weight on an old car such as this.

When all was said and done I was handed this beautiful piece of paper. Propulsion: Electric and Power: 12,8 kW. The power was printed on the identification plate of the motor and that sufficed.

Good times. Now back to the bench. The motor support had bent again and needs even more reinforcing. What I don't have to fear anymore is the bureaucrats suddenly changing the rules.

sunnuntai 11. toukokuuta 2014

Electrician's approval

The Finnish Transport Safety Agency, or Trafi for short, requires that all M-class vehicles be inspected by a qualified electrician when converting to electric drive. Yesterday, I had a visit from two such individuals and we filled a form suggested by the chairman of Sähköajoneuvoyhdistys (Electric Vehicle Association of Finland). Most of the time was spent pondering on what we should exactly be measuring, but we figured it all out in the end. All tests passed with flying colours. Next up, the registration inspection.

As a bit of bad news, two of my old 40 Ah cells shot up to well over 4 volts while charging both packs in parallel. I had bottom balanced everything pretty well this time, so either they've lost some capacity before or charging two packs of different Ah does not work as I thought.  I'm sort of leaning towards lost capacity, since I wasn't quite as thorough with my balancing when I did it a couple of years back and I pushed these cells down to 2 volts a couple times, so I may have hurt these two or they were bad to begin with. I had marked these two cells as A and B when I drained them earlier, because they were at a lower voltage than the rest of the cells, which would also suggest that they in fact are lower in capacity than the rest. I'll need to get a couple new cells or figure out another solution. As a stopgap I can always drop the front pack offline by using the service switch, which both front and rear packs now have.