Dr.Frankensickle
1 µW
- Joined
- Jan 31, 2013
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- 4
I'm new around here just dropped by to say hello,and hopefully learn a few things.
Howdy,New around here
- Thread starter Dr.Frankensickle
- Start date
litespeed
100 kW
Welcome! So what are you looking to build and/or buy? What's your fancy.
Tpm
Tpm
Dr.Frankensickle
1 µW
- Joined
- Jan 31, 2013
- Messages
- 4
Well,just looking to gain a bit of brain gain,not real smart but I have a few toys.My main goal is to find out about a battery pack in lithium to someday replace the fla"s in an electric vehicle conversion.The pack is dead and has been for some time 144 volts of 6 volt trojan t125's 24 batts in total 156 volts nominal.Just wondering how many thousand a lithium pack and charger might run.It still has a Russco charger for the fla's.The motor is a Warp 9,it is in a 69 chevy van cut off to make a cab over truck.I had fun with it but hope to upgrade and get away from fla batts.
Depends. How many amps peak does the system pull and for how long, and how many amps continuous? You need to know that to know the "C-rate" of cells that you must build the pack from, and how many parallel or how large a cell you will need to get.
Which kind of cells you can use will also be determined by how much DIY you can do, or how big your budget is to have someone else build a pack from them, and/or whether the vendor or manufacturer makes/sells mounting/etc hardware.
Assuming "t125" means "125Ah", then considering FLA's peukert losses that's about 60Ah, then you don't need a very large capacity pack, unless you use low-C-rate cells and have to parallel a number of them to reach the amps the system will need.
You said 144V, 156V nominal. What's the max voltage? (I suspect you have the numbers mixed up, and mean 144V nominal (average) and 156V full). What's the minimum voltage the system must have?
Most Li cells will be either 3.2V or 3.7V nominal (average) voltage, so depending on type you'd need about twice as many of them in series as you have FLAs.
Thundersky / CALB / etc type LiFePO4 cells are common for such conversions, cuz they're already in plastic casings and are relatively easy to strap into packs, and bolt interconnects to. Lots of examples of that on EVAlbum and on DIY Electric Car forum.
A new option recently available is EIG NMC cells, of which there are some recent discussions in the Battery forum and in the Online Market section. But they are only 20Ah each, so you'd have to make mounting and paralleling / seriesing setups for them. You'd need less in series than with the TS/CALB types as their voltage is higher, but more in parallel cuz their capacity is lower. I'm not sure if EIG will also sell the moutning hardware or not, or just the cells, at least in small amounts.
There are also EIG LiFePO4 cells in the same physical format.
Which kind of cells you can use will also be determined by how much DIY you can do, or how big your budget is to have someone else build a pack from them, and/or whether the vendor or manufacturer makes/sells mounting/etc hardware.
Assuming "t125" means "125Ah", then considering FLA's peukert losses that's about 60Ah, then you don't need a very large capacity pack, unless you use low-C-rate cells and have to parallel a number of them to reach the amps the system will need.
You said 144V, 156V nominal. What's the max voltage? (I suspect you have the numbers mixed up, and mean 144V nominal (average) and 156V full). What's the minimum voltage the system must have?
Most Li cells will be either 3.2V or 3.7V nominal (average) voltage, so depending on type you'd need about twice as many of them in series as you have FLAs.
Thundersky / CALB / etc type LiFePO4 cells are common for such conversions, cuz they're already in plastic casings and are relatively easy to strap into packs, and bolt interconnects to. Lots of examples of that on EVAlbum and on DIY Electric Car forum.
A new option recently available is EIG NMC cells, of which there are some recent discussions in the Battery forum and in the Online Market section. But they are only 20Ah each, so you'd have to make mounting and paralleling / seriesing setups for them. You'd need less in series than with the TS/CALB types as their voltage is higher, but more in parallel cuz their capacity is lower. I'm not sure if EIG will also sell the moutning hardware or not, or just the cells, at least in small amounts.
There are also EIG LiFePO4 cells in the same physical format.
Dr.Frankensickle
1 µW
- Joined
- Jan 31, 2013
- Messages
- 4
Yes sir,156 full volts,I have seen it pull 500 amp under hard accelleration,however it uses more like 100-225 amp,less if you feather it.I will look into the ev car places again.I used to belong to a yahoo group on ev's that was kind of regional for me.I can do alot of mechanical things but tech is hard for me to grasp unless put into simple terms.I got involved in electric longboards,but all I did was put different decks on existing systems.I have converted 2 of those to lithium and one was already intalled with lithium from the mfg'r.I have the 1st production one out the door from FFR trikes and a Home built full suspension bike powered by 80 volts lithium,built by a guy in Kansas City.I have over 3300 miles on a X2 segway.I have had 0 tssues with the segway,I have never taken it apart,which has been a remarkable change for me. just charge and ride.I was hoping to get some help in putting a pack and charger together to get the truck up and running again for a budget of about 8000.00,but I don't know if that is possible.The cuurent pack in the truck weighs 1600 lbs or so,and is large so a new lithium pack will be no problem as far as size and weight.I am a mechanic and mig welder by hobby,Brick and Stone Mason by trade.I have friends that are master welders and another who is a retired tool and die machinist with a full shop.Without my friends I wouldn't be able to do alot of the things I have already done with Cars and Motorcycles.I will snoop around here and see what I can absorb.Thank you for your advice.
dogman dan
1 PW
Wecome to the forum. Even though it's heavily weighted to electric bicycle enthusiasts, there are very smart people here with answers to specific questions. Likely not me, 
but others really know electronics here.
The first thing that comes to my simple mind is perhaps you could do a half lead half lifepo4 setup if 200ah lifepo4 batteries are just too pricy. So each "cell" would be a section of 12v lead battery paralelled with a 12v section of lifepo4 battery. You'd slightly undercharge the lifepo4 by charging to the lead batteries full charge voltage, but that would just help the lifepo4 last longer. On the discharge, the lifepo4 would help recharge the lead for awhile, since it's discharge curve is much flatter, keeping it's dod less, and extending it's lifespan.
Better still though, if it's in the budget to just put 200 ah or so of lifepo4 in there.
Don't know if you are into bicycles, but several of us have built some good examples of the "frankenbike". Amberwolf inspired me to build one of my own.
but others really know electronics here. The first thing that comes to my simple mind is perhaps you could do a half lead half lifepo4 setup if 200ah lifepo4 batteries are just too pricy. So each "cell" would be a section of 12v lead battery paralelled with a 12v section of lifepo4 battery. You'd slightly undercharge the lifepo4 by charging to the lead batteries full charge voltage, but that would just help the lifepo4 last longer. On the discharge, the lifepo4 would help recharge the lead for awhile, since it's discharge curve is much flatter, keeping it's dod less, and extending it's lifespan.
Better still though, if it's in the budget to just put 200 ah or so of lifepo4 in there.
Don't know if you are into bicycles, but several of us have built some good examples of the "frankenbike". Amberwolf inspired me to build one of my own.
Dr.Frankensickle
1 µW
- Joined
- Jan 31, 2013
- Messages
- 4
I figured to drop 8 to 10 g on a pack and bms and charger.can anyone point me the direction of any suppliers that will actually have the stuff in stock,in the usa,and will answer the phone? thanks again.
eva-michael
100 W
- Joined
- Apr 12, 2010
- Messages
- 157
Welcome. For 156V. You will need 48S nominal 3.3V LiFePO4 or LiFeYPO4.Dr.Frankensickle said:
It will be about 800lbs for 48S 200Ah. You will over budget. It's about 11000usd.
160Ah should suit your budget. Anyway. most important is if it suits your driving range.
I will also recomand you to diyelectriccar also. It's another good place.
I don't know many US vendors for cells as large as you want/need. Only one I can remember the name of right now is Elite Power Solutions that I think is based here in Phoenix, AZ, but I don't know if they actually stock stuff or if they drop ship from China.
