So, I'm thinking that adding some cells to my XM-3500Li might be worth a try as a first level upgrade, but I must admit I'd really like to have a BMS (that I don't have to solder together and is at least a somewhat reasonable cost) available before doing it. (Plus I'm curious to see how all the other temperature tests other folks are doing before I submit my motor to the 100 degree, 100% humidity August weather around here in new Orleans.) But I did see some discussion here on the use of a Voltphreaks single cell LiFePo4 charger for doing individual cells to balance them out as a cheap alternative. So I bought a couple (//s.p10.hostingprod.com/ [at] www.voltphreaks.com/ssl/catalog/product_info.php?cPath=3&products_id=28">https://s.p10.hostingprod.com/ [at] www.voltphreaks.com/ssl/catalog/product_info.php?cPath=3&products_id=28) and thought I'd like to dig into maybe trying to start doing this cell by cell sometime soon.
Now this thing has normal little round plug (like you might use on many types of electronic equipment) which I will obviously need to cut off and split out the wires. I also know I'll need to make sure which wire is the positive side and which the negative (and a strip of red tape might help me see it on the fly.) Presumably the battery to be charged will need to have any leads on it removed before connecting to this little charger, but are there any recommendations for making the connection? Obviously I could just strip the wires and try to wrap them around the battery terminals, but do other folks have some recommendations on little ends I could put on that maybe I could get at Radio Shack or online somewhere? And are there any other considerations I should know about charging this way? Does this charger shut off appropriately for these batteries when they are fully charged without overcharging them?
And if I did want to add batteries into the mix eventually, how do you do that? Let's say I started by adding 1 battery. How would I connect it into the mix, meaning which battery (or batteries) terminals would I need to connect to? What about if I added 4 batteries?
If you do not know what to do, you are putting yourself, and your bike, in harm's way.
You do not need to disconnect any wiring, in fact you might want to add some. Make sure the main breaker and ignition are OFF.
You need a safe electrical connection to the cell you want to charge. Wrapping bare wires around terminals is not really safe. One slip, short the cell, 500 or 1000 amps flow, melt the wire, and molten metal flies into your eye! Wear eye protection when working around batteries.
The VF charger "should" not charge the cell beyond about 3.6 (approx.) volts, so there should not be over-charging.
If you do not have "clear" (unobstructed) access to the cell's terminals (or, to something connected to the terminal), you might consider wiring the cells (through fuses) to a more convenient charging "connector" and location.
Consider not cutting the end off the VF charger, but adding a mating (2.5 mm center, I believe) connector wired (0.25 inch crimp-on ring terminals) to each cell.
Mostly, be very careful, and if not sure of what you are about to do, ask more questions.
Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.
And thus my reason for asking here. I can take the bike apart, and have plenty of experience with electrical wiring on the macro (home and general building wiring in 110 and 220) scale and even some with small electronics (chip-level soldering and relatively basic PCB stuff.) So I'm well aware of the dangers, but living is a mortal risk so...
Thanks for some of the input it's just that I'm not familiar yet with the terminology for this level of stuff, yet. So letting me know about a 0.25 inch crimp-on ring terminals is a big help and just the kind of info I need. I'm not worried about working around electricity, I'm very familiar with and careful when dealing with it. I just need more of the details is all. Like not being sure if while connecting to charge one battery that current would be carried down the connecting wiring drawing off current to other batteries or otherwise tricking the charger into reading the wrong level of current in the battery it's charging. I take it by your suggestion that I would not need to remove any wiring that this would not be the case?
Lenny Zimmermann
Metairie, LA
Hey Lenny buddy-- good question and I am in the same situation as Lenny as far as experience too so I am all ears here. Best Mikie
mikie
Hi Lenny, Those are all questions I had too. The wire with the white dashes is the positive on those chargers. I just cut the end off mine and soldered on clamp type charging connectors that I got at pep boys 4 for 2.99(like on a car charger only smaller) You don't have to disconnect anything just make sure your get the polarity right. If you mess up we'll just nickname you flash and you'll need a new charger. It's not that big a deal. You can use multiple chargers at once as long as they're not right next to each other. The light on the charger will turn green when the battery is at about 3.68 to 3.7v. start at each end and work to the middle is the easiest way. keep track of how long it takes each cell to fill up (If you can). That will give you a good idea of how balanced your pack was. Another helpful tip is that the clamp doesn't have to be right over the terminal that you want. That is, the terminals that are bridged can serve as either so when the terminals are under a tube and hard to reach if it's a bridged terminal you can attach it where it's easier to reach. Just be carful when doing this dont get confused. You way not understand now but you'll see what I mean when you start in the front. Fully charge it first also, that will save time. I did mine all at once but I think it would be fine to do a few at a time if you have to. Just always start with a full charge. Just post if you have any other questions. One more thing, I would NOT use ring terminals because then you have to take each bolt all the way out.(BIG PAIN IN THE @ss)I would use spade connectors, if you already have the rings you can cut the tops off with side cutters, suit youself but if you tighten everything down good (and you should) they'll be fine. Just make sure you get them under both washers. You can just loosen it up, slide it under it's much easier.
Hope I didn't miss anything.
Mikie I ordered a IR temp gage, I'll post some temps when I can.
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
Lenny, I thought I should clarify about the bridged terminals. In the front at the most positve terminal...It's under a tube, right? so you connect to that cause you have to. Now the negative could be connected to either side of that next bridged terminal. Sorry if I'm pointing out the obvious but I was a little confused about that at first. This is just helpfull on the terminals under the frame tube that can be hard to reach. If many of your cells take a long time to top off...you're going to be very happy when you're done. I'm getting about 10 more miles range now that I did mine!
PS Taking the seat off makes it easier and isn't very hard to do.
Happy Riding - Bill
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
Lenny - we're planning on making our BMS (based on the Goodrun/Fetcher design) available to others. We won't be selling them ourselves but we plan on making more than we need and then will wholesale the extras to a couple of places (including TPPacks (Gary Goodrun's store).
Hopefully in the not too distant future there will be a selection of BMS's to choose from.
In the meantime good luck with your upgrades.
John H. Founder of Current Motor Company - opinions on this site belong to me; not to my employer
Remember: " 'lectric for local. diesel for distance" - JTH, Amp Bros || "No Gas.
I suggest the full ring terminal instead of the spade for permanent wiring. Being the same thickness all around it will tighten down more uniformly and cannot vibrate out of an accidently too-loose connection.
Yes, it is a bit harder to do, but not too much harder. And really, one should add a fuse (maybe 5 amps) right near each connection.
Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.
Icarus, just what I was looking for. Thanks! I did realize what you meant about the bridged negatives, but it's definitely good advice since I'd rather not take off that entire panel to fully expose the batteries (since you have to take everything else off first just to do that, blech.)
John, good to hear. I know the Green BMS is progressing as well. I'll definitely be looking forward to whatever comes out!
Gary, good input on the ring connectors. For now I like Icarus' idea for the clamp connectors, but once I do get a BMS putting in something more permanent like that may well be the way to go. It'll be more of a pain to get in, but considering the state of the roads around here it'll probably work out a lot better to have a definitively solid connector on there.
Thanks for the feedback, all. It's really appreciated.
How about adding batteries, though? I don't really need it just yet, but how would you add in 1 more or 4 more batteries? Which battery do you connect it/them to and what's the best way to link them to each other? Presumably the TS charger would no longer really work right for all batteries connected in if there are more than the original 20, so is there a good way (before getting a BMS) to charge them? Maybe disconnect the spare(s) and charge them with the single charger while the rest are charged normally?
Lenny Zimmermann
Metairie, LA
Lenny, If you add batteries the best thing to do is add 4cells or 8cells. If you add 4 the choice is buy a new charger from elite (TSL72-15) which is designed for 24 40AH cells or keep using you stock charger and get a 4cell lifepo4 charger. I found one for $34 (I'll find the link and post it)but I would just get the new charger because otherwise you will have to disconnect the added 4cells to charge them. I'm runnig 28cells now and use the TSL72-15 to charge the 24 (only takes 2.67 hrs) and the 4cell charger to charge the other 4.(if you had 28) I installed battery disconnect switches (available at auto parts store) so I dont have to keep removing the terminals for the extra 4 cells. It gets kind of expensive with the discon. switches costing about $17 each (you would need three). I would just go 24 because they fit in easy and you still have the underseat storage. When I went to 28 I had to put 4 behind the seat brace so the plastic storage compartment gets left behind(dead wieght)I think you may be able to fit all 8 in front of the seat brace(I'm going to try this I'll let you know)
Elite ships the 4 cells with all the connectors and the box to hold them. You just disconnect the negative at the back of the box, attach a cable (get at auto parts or make your own) to that negative post to the positive post on the new set then attach the bikes negative (that you took off) to the most negative on the new set. You can just use zip ties attached to the strings on the batt box to stabilize the new cells that should rest comfortably on top of the stock batts in front of the seatbrace. I leave the storage compartent screws out so I can remove it easily to inspect things. It's fine that way, it's not going anywhere. Actually right now I'm leaving the compartment out there's more room in there without it. But I have a GIVI so it doesn't matter. you get about 1.5 MPH per added cell.
Hope that was helpful-Bill
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
What 4-cell charger do you recommend for the LiFePO4 "mini-pack"?
Where does one get it?
IF the 4-cell charger you use has an ISOLATED OUTPUT, it is not necessary to have any disconnect switches in the pack wiring.
Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.
Lenny,
I have 12 of the 2A VoltPhreaks chargers that I use in the lab. I attached small alligator clips from Radio Shack. The chargers can be stacked - to charge a cell at 10A, for example. The chargers can also be used to charge adjacent cells - just connect one charger to one cell, and the next to the next cell. You'll basically have two charger terminals on one 'cell connector'. This works very well. I've also used the VF chargers on individual cells while the entire pack was charging with another larger charger.
I'm building Goodrum/Fechter BMS boards for customers - I can supply you with an assembled & tested board ready to wire into your pack if you'd like.
You can add cells to your pack anywhere you want.
Andy
Should anyone be interested in 16, 32, 48 ,64, 80VOLT Lit-ion battery Pac's that have all the electronics built in to prevent overcharging, email me at cruisin [at] live.com for the info. When adding batteries to existing, this solves all problems. I have done it and it really works nice and easy.
I just found some others that charge up to 10 cells (in series) at lower amps for $47 as I was looking for the place I got the 4 cell charger. Here's the link to the 4cell smart charger http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=4952 Do a google on universal smart chargers to find more. I just wired another 3500li today for a BMS, you guys got me worrying about using those spade connectors. I hadn't actually test fitted them yet. Well it turned out they work great. Plus I figure if the terminal is that loose it's better if it does come off because the LVC cuttoff on the BMS will cut the motor,right? If it stays on, the motor keeps going till the loose terminal maybe goes chernobyl on you. Anyway if one of those leads did come off it really can't do any harm can it? The main reason I bring this up again is if you start in the front on the 1st positive you'll have to REMOVE that battery to use ring connectors. If you use good spades it makes it a piece of cake.
PS I don't know what you mean by isolated output. Let me know if you think I can charge without the iso swithches, I was wondering about that.
Gotta eat- Bill
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
Great info, guys. Thanks for all the tips!
The number of batteries to add is mainly dependent on temperature testing other folks are doing here. I'm just a bit worried about burning something out considering the high temperature and humidity around here when August rolls around. Those of you in cooler climes may have a shorter riding season (there's are seasons other than Summer? ;)) but you probably have to worry less about that additional power causing any problems. Then again, while it is my primary commuter, it's not like I don't have a car or that I don't consider this scoot fairly experimental. So I may just add them in anyway and if anything does go wrong maybe I'll go whole hog and replace motor and controller and DC converter and just boost the whole thing up. Although I supposed I'd still rather wait a bit more before going that route if I can help it.
Oh, and Andy, i may just hit you up on that BMS, but I need to make sure I've got a little extra time to strip the bike down and get it wired up for a BMS first before getting one. Not to mention I may want to decide if I'm definitely adding some batteries or not. I'm definitely leaning that way, though.
Lenny Zimmermann
Metairie, LA
Andy, How much for the boards and how can I test mine. I'm nervous about hooking it up to the pack wthout testing it. It's all ready to go, I just don't know how to test it. I have a friend who wants one. You can pm me if you don't want to quote here.
Bill- Besides I might just buy one from you and frame mine and hang it on the wall...hows that for geek chic!
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
Fortunately (or unfortunately!) I understand about geek art! :-)
Here's a quick (?) 'verbal' 'how I did it'.
All of the functions can be tested with the charger you intend to use, a volt meter, an LED, a variable resistor, and a couple of batteries. A variable power supply can be handy but isn't required.
Basically - the BMS board does three things - detects when a cell goes below 2.1V, detects whhen a cell charges above about 3.7V, and detects when all the cells are full so it can shut the charge current off.
To test the LVC function:
Setup: Connect a temporary circuit to the 'brake inhibit' connections on the board. I use a single LiFePO4 cell and an LED in series to simulate my brake circuit. (The optoisolators are switches in parallel that will turn on the LED when any one of them is turned on by a low cell detection. We'll inject 2.1V into each channel and test that the circuit detects and responds to the low voltage condition.)
Test: (I'll orient the board so the 'control portion' is at the bottom and the row of shunt resistors is to the left. We'll start on the bottom and work up.) Starting on the bottom of the shunt resistors - connect a battery with a variable resistor (or a variable power supply set to about 3V) to the first two shunt resistor leads - bottom resistor (closest to the FET) is negative, resistor two is positive. Slowly turn the voltage down until you get to around 2.1V. Watch that the 'brake' LED lights when the voltage drops below 2.1V. (Radio Shack alligator clips are handy for this - and can connect to the leads of a volt meter so you can see the exact voltage.)
Move the voltage back to about 3V, move the positive lead from resistor two up to resistor three, move the negative clip from resistor one to resistor two, and turn the voltage down to test the LVC for channel two.
Repeat until all the channels have been tested. The last test - at the top of the board - will between the top resistor and the 'pack positive' conection on the corner of the board.
You're done with the LVC testing - you can disconnect the battery/LED circuit from the brake inhibit connections.
To test the shunt function - you'll need somewhere between 3.7 and 4V. I use either a bench power supply or two LiFePO4 cells in series.
You'll connect the power to the resistor leads exactly the same way you tested the LVC. This time, though, you'll be moing from below 3.5V up to about 3.8 or 3.9. You're looking for the orange 'shunt LEDs' to start to come alive somehwere around 3.65V and be full on at around 3.7V. There's a bit of range here due to parts tolerances - so don't get too picky about two digit precision. :-) Same thing - 'inchworm' the connections up the resistors and move the voltage from low to high and make sure the orange LEDs light.
To test the control portion - run wires to the charge negaive and pack positive connections so you can connect to you charger. Bridge the small 'control enable' connection to the 'charge negative' connection - this turns the control section on. When you connect the charger and turn it on, the control LED should be reddish orange and the orange shunt LEDs should light. If the charger isn't making quite enough power, the control LED will stay reddish. If the charger can make enough power to completely charge the pack, the led will be mostly green. You may get an end of charge latch - if so, the LED will go full green and all the orange LEDs will go out.
If you're not going to charge thru the BMS - just use it for shunting and LVC, you don't have to worry about the control portion as you won't be using it.
Here's what end of charge looks like if you charge thru the BMS: http://www.youtube.com/watch?v=GbA5wCA_M8A
Thanks Andy, thats exactly what I needed to know. I have a volume control that will work to adjust the voltage. So if I don't connect that control negative thats right next the charge negative that will bypass the control function? Because that's probably the best thing to do since I'm using the TSL charger. Right?
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
Andy,
Great video of the BMS shunts in operation at the end of charging a very-nearly balanced 16-cell pack.
This would be from a test of one of the custom battery packs that you made for one of your customers?
Looks like you might have been using a "standard" power supply to do the charging, not a TS smart charger?
Really nice looking work.
Do you have pictures of the rest of the battery pack, please?
Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.
My pleasure! Yes - that's exactly how I'm using mine -- leave the control circuit off, charge the bike with the TSL charger thru the factory charge cable, and let the shuts keep the cells in check. You've got it!
So I decided to go for adding 4 cells, cross my fingers and hope for the best. The pack of 4 I got from Elite was strapped together with little rope handles, which was convenient. It wasn't bridged across the cells, though. I had to make little shunts to do that myself, so I hit Radio Shack. The thickest gauge they had was 10 gauge automobile electrical wiring. More than a few of the wires coming off the batteries in the XM-3500Li are smaller then that, so I figured it would work. They didn't have any ring wire connectors, only gold-end spades, so I figured I'd make do with those. The shunts between the batteries will hold each other in place with pressure since I made them like >--< so they'd bridge the gap directly. I did solder the ends into place on the wire, though, so that should help keep things working well. Otherwise on the newly added wire to run down to the negative I just tried to make sure everything was down tight.
The battery did come with the caps for the posts, though, so that was helpful being able to put those over everything to protect it all. The cells were at around 3.4V (if I remember right) and I had just driven the scoot home from work so I thought I would check where they were at to see if was going to be a while to get al the cells evened up, but luckily the cells on the scoot were at the same 3.4 level! Sweet! So i was able to install the batteries last night.
The charger didn't have the standard "computer power cord" end that the bike has, though. It came with another connector I could have replaced it with, but it was nowhere near the same size, so I just cut up an old computer cord I had, cut off their connector and then soldered up the wiring and wrapped it all in electrical tape. So that works. I probably could have just used wire ties like I do on the house wiring, but I figured what the heck I had the soldering gun out anyway.
Top speed went from 39 to 46 mph. I was a little worried (well, not that much) that the initial acceleration might be stronger, but it really isn't. I did notice that overall acceleration at speed seems improved, though. Maybe it just moved the acceleration curve higher, but even so it's nice to have when traffic around you is going 40 MPH as it's VERY helpful to have the option to accelerate to get out of a situation if needed.
Now we just have to see if the other shoe is going to drop when we hit August heat and humidity here so we can find out if the motor will just un-glue itself with all that extra stress. :/
Lenny Zimmermann
Metairie, LA
Congratulations Lenny, It's a big difference right? I think the motor may run cooler at higher voltage. You should have got all the copper strips and hardware with the batteries . Are you sure you didn't throw them out by mistake with the packaging? Email them thet'll send you the stuff. Well you can never go back now (to 20 cells)... I tried because I thought something might happen but that didn't last long. I have about 3000km on 24cells and between me and a friend have about 2000km on 28 cells. When it gets hot I'll do a long run at full throttle and take some temperatures.
Happy Ridin
PS summer in LA. ouch!
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
Lenny, I just remembered something that happened to me that you should know. If you follow the wire from the stock charging port you will run into a connector a short distance from the charging port. When I started charging with the 15 amp TSL charger I noticed this connection was getting warm. one day I was charging and I was looking at things and moved the charging wire a little bit and the charger suddenly stopped charging. I jiggled the wire a little and it went back on. I took the connector apart and found that there is some kind of "weak link" aparently so that it will fail there first if overheating. It had melted through and had a bad connection. I ended up cutting this part off shortening the wire and using spade connectors so I can attach the old or the new type of connector so I could use either charger incase the 15amp one quit working. Once I did that nothing got hot anymore. Those new grey connectors (anderson I think they're called) are much easier to pull apart and get together. If you do this make sure to put opposite gender(insulated) spades (or barrel) on the + & - so you can't reverse polarity by mistake. I don't know if you got the new charger to or opted to stay at ten amps and use two chargers. If the latter it won't matter. Anyway what you end up with is two little short adapters one with the new type and one with the computer type connector.
I should add that this failier may have been my fault as I had had that connecton apart before and had trouble getting it back together properly.
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
I bought the charger, so I'll keep an eye on that. It does seem the new charger draws more power. The bike seems to charge faster and I noticed the plug will have gotten a little warm when I go to unplug it (not hot or anything, just a bit warm.) I also had to find an outlet with very little else on the circuit, too, as it was popping the breaker right and left and several other outlets in the house (although I should note that the outlests I first tried do share the line with several other higher-drain items like my computer & home-theater equipment and such like that.) At any rate I'll keep an eye out for the problem you mentioned.
The box from Elite definitely did not include any copper connectors or anything, though. That's OK, since I've already made those connectors anyway and they should work just fine so I'm not too worried about it. It did come with a bag with the single and double protector caps and all of the post screws, washers and lock washers.
Thanks for all the tips and help!
Lenny Zimmermann
Metairie, LA
Just a quick update. Temperatures were in the 100s yesterday (heat index today is supposed to be around 108) and they've been in the 90s for a couple of weeks now with no end in sight (par for the course for summers around here, though, although 104 at Audobon Park was a record breaker, although average in the area of my commute was probably more around 101, all of this with humidity in the 80s) and so far so good. YMMV, of course, and there are plenty of other factors here that may prevent a motor meltdown, such as a relatively short commute of 11 miles each way and that I'm more often on full throttle on the last half of the ride in the mornings when it's cooler, whereas that's the first part of the trip home in much hotter afternoons so the motor is already cool and by the time it heats up is closer to when I'm doing more stop and go driving (although I supposed the starts could cause some excess heat, but I would think the build-up would be more pronounced at full throttle). Not to mention we're only talking a couple of weeks of 90+ degree weather and we haven't even hit August yet, so even if there were some internal damage from the heat it may not be showing up yet. But so far I'm giving a tentative thumbs up on adding those 4 batteries. There've been no obvious issues with it up to this point.
Lenny Zimmermann
Metairie, LA
Hey Lenny-- how do you like the extra power? What charger are you using and how much do the voltages vary? Are you using a BMS? Best....Mikie
mikie
Yeah it's heating up here too. I haven't even bothered taking temp readings, my motor is staying cool enough the controller seems to get a little hotter than the motor even. Regen is awesome and I just got a cycle analyst which will give me data on how much I'm getting back from regen braking. The unexpected thing is how nice it is to brake... with one finger basically. It's really effortless. I don't know about everyone else but it seems you have to pull pretty hard on those brake handles when you want to stop fast without regen.
I love my scooter more every week...silent acceleration, what a thrill.
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
By coincidence, the 5.5 mm jacks on my Battery Interface Fuse board will fit the Voltphreaks one-cell 2-amp (approx 3.65 volt) charger.
No cut and try to connect, just plug in one (or many). No BMS needed because each cell is individually charged (supposedly) only to 3.65 volts (approx 2 amps max).
After doing the "bulk" charging with the TS charger on my 5000Li, I will have to try a final balance-charging of 8 (or 12 or all 21) cells and log all the cell voltages (with my PakTrakr and PtViewer program). I will report the results.
I guess I need five 6-outlet (or eight 4-outlet) AC plug strips.
Cheers, Gary
XM-5000Li, wired for cell voltage measuring and logging.
It's in the thread, I bought the charger Icarus recommended. I haven't checked voltages recently, but I'll try to in the near future, and still no BMS yet.
As for liking it, no change in opinion from above. It's mighty nice having some acceleration room on the streets I drive for my commute, not to mention that I can at least get on the slightly faster roadways now, if needed. So while it would be nice to be able to get into the 50mph range (to have that acceleration room on those 40-45mph roadways the few times I need to get on them) I can at least fel comfortable now with just the 24 battery upgrade. The stock setup just wasn't cutting it.
Lenny Zimmermann
Metairie, LA
Been a while since I've posted any updates on this. But I thought I would throw in a few more notes. I did measure the levels not that long ago, I don't remember what it was now, but everything is all still very level (and I'm still not even using a BMS.) I did notice something interesting, now that I've had the bike going through it's second winter, in that when the weather is warm I can get that 45mph top end, but that top speed does gradually drop when it's cold so it seems to top out around the low end of 43 mph when the weather is in the 40's (F). It was something I'd noticed somewhat without the added battery pack, but at first I thought it might be an issue with balance. When I saw it happening again with the added pack I checked and didn't see any issues there. Recently, though, we had a rather balmy day in the upper 70s and I was just barely hitting that 45 mph top end again. Once the temp dropped back down, it was back to 43. Just an interesting observation I thought folks might like to hear about in case other run into the same situation.
Lenny Zimmermann
Metairie, LA
Hi lenny, Yeah I've noticed the same thing. I think it's mostly the denser air at lower temperatures, coupled with reduced battery performance as well. Glad to hear your still running well...same here.
Take care- Bill
2008 XM3500li Mods/Kelly KBL12251/84v 28cell 40AH pack/ Variable regen brake trigger on left brake handle/Givi/Cycle Analyst/Homemade BMS
KMX Typhoon Home build (recumbent pedelec) with two Astro Brushless 3220motors/twin castle Phoenix ICEHV 160/ Cycl
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