S10-EV Mailing List Archive

Just thinking out loud about a possible Lithium conversion.
The Tesla battery approach seems to be a good answer, however, there are some issues with the S10E. Mainly the voltages sent to the S10E battery computer. An option here would be to convert your S10E into a back yard EV conversion by removing all of the control components and simply using the drive train. I don't want to attempt this or hack up a great truck. The Tesla battery uses 18650 Lithium cells in series and parallel. Nominal voltage of the 18650 is 3.7 volts. Fully charged is 4.2 volts. Totally dead is about 3 volts. So 3 in series, (12.6 volts fully charged), would cause problems for our computer and probably over charging to the point of exploding. However, 4 in series would be 14.8 volts, nominal and 16.8 volts fully charged. They could handle even a balancing charge. Our truck's charging system would limit the charge to about 13.8 volts which would also extend the cycle life of the 18650's. But, 4 in series would be depleted at 12 volts. Our trucks low limit is 10 volts, so we would have to pay attention to the total pack voltage and re-charge at something above 312 volts.
Of course, most of these problems could be solved if a new battery and charging algorithm could be written into our BMS. I have no clue how to do that.
The main motivator here is price and range. A 120 amp hour pack made up of 4,160- 18650's will fit in out battery box. The easy to find price of an 18650 is between $3.50 to $6.00 each. However, I know of a pallet of 20,000 cells that just sold for $1.00 each. These were genuine LG HG2 18650's at 3000mah. If I had the answers to the issues I've posted here I would have bought 5000 of them.
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Hi Kevin and all,  I'll chime in here.I pretty much consider successfully messing with the trucks soft firm ware as an impossibility since i wouldnt know what i was doing.  so you'd pretty much have to fool the BPCM into thinking all is well in the battery box.  
One of the thoughts I had was to make a voltage reference board to which i would connect all the battery sense lines to the BPCM,  kinda of a voltage divider with the full pack voltage feeding it.  then when as the battery pack voltage moves up and down,  so too would the sense lines.   (of course i'm talking about a lead acid s10) 
Mechanically,  working with hundreds of small cylindrical cells would be problematic,  but perhaps working with larger rectangular cell, like a 60ah, would be an easier solution.   4 cells in series would make up a nice module.    i was trying to imagine a material that could be cut into strips and used as a  separator,  maybe only 1/8" thick but would allow some air flow between the cells.   maybe a two module  (8 cell) pack could be assembled on the bench as one unit.    The floor of the battery box could be replaced with a sheet of similar material , ABS or PVC, that could be water jet cut with new air holes that align with the new modules.  stops could be glued to this plastic to contain each module from moving around.  
of course,  a BMS would be very necessary as may be an external charger or finish charger.    I suppose a truck with the NIMH flash might be a better candidate since the BPCM is counting amp hours .   I dont know what the fuel gage would do nor if the equalize charge every 11 cycles would hurt the batteries, since the BPCM is looking for 16 volts each module.  
The late Bill Korthoff suggested to me one time that the NIMH battery from the first generation Rav4 (also in the Ranger?) would probably install in a lead truck and function well with the existing charger,  though they might need topping up with an external charger periodically.  dang,  i'd be happy with that.   
My 98 truck is still running on the lead acid hybrid battery from panasonic which is still a very nice commuter and grocery getter.  GM has pushed the price up to $700 a module from the original $165 to discourage purchase.  i think the reserve of batteries for the  GMC hybrid truck are gone since the last one or two i purchased had one month old date codes.    The sad thing is that in Japan,  the 1260 panasonic (used originally and in the EV1) is most commonly found in Japanese gold carts, so the availability over there must be very good.    
Eric L On Thursday, August 3, 2017 9:15 AM, BJNKM--- via S10-EV <[email removed]> wrote: Just thinking out loud about a possible Lithium conversion.The Tesla battery approach seems to be a good answer, however, there are some issues with the S10E. Mainly the voltages sent to the S10E battery computer. An option here would be to convert your S10E into a back yard EV conversion by removing all of the control components and simply using the drive train. I don't want to attempt this or hack up a great truck. The Tesla battery uses 18650 Lithium cells in series and parallel. Nominal voltage of the 18650 is 3.7 volts. Fully charged is 4.2 volts. Totally dead is about 3 volts. So 3 in series, (12.6 volts fully charged), would cause problems for our computer and probably over charging to the point of exploding. However, 4 in series would be 14.8 volts, nominal and 16.8 volts fully charged. They could handle even a balancing charge. Our truck's charging system would limit the charge to about 13.8 volts which would also extend the cycle life of the 18650's. But, 4 in series would be depleted at 12 volts. Our trucks low limit is 10 volts, so we would have to pay attention to the total pack voltage and re-charge at something above 312 volts.Of course, most of these problems could be solved if a new battery and charging algorithm could be written into our BMS. I have no clue how to do that.The main motivator here is price and range. A 120 amp hour pack made up of 4,160- 18650's will fit in out battery box. The easy to find price of an 18650 is between $3.50 to $6.00 each. However, I know of a pallet of 20,000 cells that just sold for $1.00 each. These were genuine LG HG2 18650's at 3000mah. If I had the answers to the issues I've posted here I would have bought 5000 of them.Kevin McMullin   _______________________________________________
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Hi Eric,
Thanks for the input. I think the 18650 cells are a better choice for several reasons. The Prismatic cells, often called "Yellow Bricks", don't have the energy density of 18650's and you can't even fit a 100 AH pack in our battery box. However, at 3.2 volts per cell, 4 in series would make the BPCM happy. You would need 104 cells to make up a pack and at $390 each, over $40K. https://jet.com/product/detail/9d9e03ce1ef847ac8bd1b54ac1da6f86?jcmp=pla:ggl:NJ_dur_Gen_Electro
nics_a1:Electronics_Adaptors_Cables_Power_Battery_Chargers_Accessories_a1:na
:PLA_785706707_43734982769_pla-292115566960:na:na:na:2&code=PLA15&pid=kensho
o_int&c=785706707&is_retargeting=true&clickid=e6d0d8b1-3c5f-46e9-8854-3af6b0
73daf6
I'm sure there are better prices out there but this was a quick check.
And their C rating is only about 3. The 18650's are 10 C.
If I could get the $1.00 each deal, 18650's would be less than a new lead acid pack. I know just enough about electronics to get me in trouble. Tricking the BPCM would solve some issues but with these 3.7 volt cells, you have 2 choices. 3 in series, 11.1 volts, too low. Or 4 in series, 14.8 volts, too high. You could probably trick the BPCM to see the voltages it wants but the rest of the drive train will see the real voltages. A 4 in series pack would be 436 volts fully charged. A lead acid pack is about 327 volts fully charged. Not sure if the components could handle the extra voltage. But as I'm writing this, a lead acid pack that just went through a balancing charge would be 416 volts. Hmmm. For separating the cells I use core-plast. It looks like corrugated cardboard but it's plastic. Cheap, easy to cut, strong and it flows air well. Same stuff they use for yard signs and it comes in several thickness's. Kevin M. In a message dated 8/4/2017 9:22:51 A.M. Eastern Daylight Time, [email removed] writes: Hi Kevin and all, I'll chime in here.
I pretty much consider successfully messing with the trucks soft firm ware as an impossibility since i wouldnt know what i was doing. so you'd pretty much have to fool the BPCM into thinking all is well in the battery box. One of the thoughts I had was to make a voltage reference board to which i would connect all the battery sense lines to the BPCM, kinda of a voltage divider with the full pack voltage feeding it. then when as the battery pack voltage moves up and down, so too would the sense lines. (of course i'm talking about a lead acid s10) Mechanically, working with hundreds of small cylindrical cells would be problematic, but perhaps working with larger rectangular cell, like a 60ah, would be an easier solution. 4 cells in series would make up a nice module. i was trying to imagine a material that could be cut into strips and used as a separator, maybe only 1/8" thick but would allow some air flow between the cells. maybe a two module (8 cell) pack could be assembled on the bench as one unit. The floor of the battery box could be replaced with a sheet of similar material , ABS or PVC, that could be water jet cut with new air holes that align with the new modules. stops could be glued to this plastic to contain each module from moving around. of course, a BMS would be very necessary as may be an external charger or finish charger. I suppose a truck with the NIMH flash might be a better candidate since the BPCM is counting amp hours . I dont know what the fuel gage would do nor if the equalize charge every 11 cycles would hurt the batteries, since the BPCM is looking for 16 volts each module. The late Bill Korthoff suggested to me one time that the NIMH battery from the first generation Rav4 (also in the Ranger?) would probably install in a lead truck and function well with the existing charger, though they might need topping up with an external charger periodically. dang, i'd be happy with that. My 98 truck is still running on the lead acid hybrid battery from panasonic which is still a very nice commuter and grocery getter. GM has pushed the price up to $700 a module from the original $165 to discourage purchase. i think the reserve of batteries for the GMC hybrid truck are gone since the last one or two i purchased had one month old date codes. The sad thing is that in Japan, the 1260 panasonic (used originally and in the EV1) is most commonly found in Japanese gold carts, so the availability over there must be very good. Eric L On Thursday, August 3, 2017 9:15 AM, BJNKM--- via S10-EV <[email removed]> wrote: Just thinking out loud about a possible Lithium conversion.
The Tesla battery approach seems to be a good answer, however, there are some issues with the S10E. Mainly the voltages sent to the S10E battery computer. An option here would be to convert your S10E into a back yard EV conversion by removing all of the control components and simply using the drive train. I don't want to attempt this or hack up a great truck. The Tesla battery uses 18650 Lithium cells in series and parallel. Nominal voltage of the 18650 is 3.7 volts. Fully charged is 4.2 volts. Totally dead is about 3 volts. So 3 in series, (12.6 volts fully charged), would cause problems for our computer and probably over charging to the point of exploding. However, 4 in series would be 14.8 volts, nominal and 16.8 volts fully charged. They could handle even a balancing charge. Our truck's charging system would limit the charge to about 13.8 volts which would also extend the cycle life of the 18650's. But, 4 in series would be depleted at 12 volts. Our trucks low limit is 10 volts, so we would have to pay attention to the total pack voltage and re-charge at something above 312 volts.
Of course, most of these problems could be solved if a new battery and charging algorithm could be written into our BMS. I have no clue how to do that.
The main motivator here is price and range. A 120 amp hour pack made up of 4,160- 18650's will fit in out battery box. The easy to find price of an 18650 is between $3.50 to $6.00 each. However, I know of a pallet of 20,000 cells that just sold for $1.00 each. These were genuine LG HG2 18650's at 3000mah. If I had the answers to the issues I've posted here I would have bought 5000 of them.
Kevin McMullin _______________________________________________
S10-EV mailing list
[email removed] (mailto:[email removed]) https://pairlist5.pair.net/mailman/listinfo/s10-ev In a message dated 8/4/2017 9:22:51 A.M. Eastern Daylight Time, [email removed] writes: Hi Kevin and all, I'll chime in here.
I pretty much consider successfully messing with the trucks soft firm ware as an impossibility since i wouldnt know what i was doing. so you'd pretty much have to fool the BPCM into thinking all is well in the battery box. One of the thoughts I had was to make a voltage reference board to which i would connect all the battery sense lines to the BPCM, kinda of a voltage divider with the full pack voltage feeding it. then when as the battery pack voltage moves up and down, so too would the sense lines. (of course i'm talking about a lead acid s10) Mechanically, working with hundreds of small cylindrical cells would be problematic, but perhaps working with larger rectangular cell, like a 60ah, would be an easier solution. 4 cells in series would make up a nice module. i was trying to imagine a material that could be cut into strips and used as a separator, maybe only 1/8" thick but would allow some air flow between the cells. maybe a two module (8 cell) pack could be assembled on the bench as one unit. The floor of the battery box could be replaced with a sheet of similar material , ABS or PVC, that could be water jet cut with new air holes that align with the new modules. stops could be glued to this plastic to contain each module from moving around. of course, a BMS would be very necessary as may be an external charger or finish charger. I suppose a truck with the NIMH flash might be a better candidate since the BPCM is counting amp hours . I dont know what the fuel gage would do nor if the equalize charge every 11 cycles would hurt the batteries, since the BPCM is looking for 16 volts each module. The late Bill Korthoff suggested to me one time that the NIMH battery from the first generation Rav4 (also in the Ranger?) would probably install in a lead truck and function well with the existing charger, though they might need topping up with an external charger periodically. dang, i'd be happy with that. My 98 truck is still running on the lead acid hybrid battery from panasonic which is still a very nice commuter and grocery getter. GM has pushed the price up to $700 a module from the original $165 to discourage purchase. i think the reserve of batteries for the GMC hybrid truck are gone since the last one or two i purchased had one month old date codes. The sad thing is that in Japan, the 1260 panasonic (used originally and in the EV1) is most commonly found in Japanese gold carts, so the availability over there must be very good. Eric L On Thursday, August 3, 2017 9:15 AM, BJNKM--- via S10-EV <[email removed]> wrote: Just thinking out loud about a possible Lithium conversion.
The Tesla battery approach seems to be a good answer, however, there are some issues with the S10E. Mainly the voltages sent to the S10E battery computer. An option here would be to convert your S10E into a back yard EV conversion by removing all of the control components and simply using the drive train. I don't want to attempt this or hack up a great truck. The Tesla battery uses 18650 Lithium cells in series and parallel. Nominal voltage of the 18650 is 3.7 volts. Fully charged is 4.2 volts. Totally dead is about 3 volts. So 3 in series, (12.6 volts fully charged), would cause problems for our computer and probably over charging to the point of exploding. However, 4 in series would be 14.8 volts, nominal and 16.8 volts fully charged. They could handle even a balancing charge. Our truck's charging system would limit the charge to about 13.8 volts which would also extend the cycle life of the 18650's. But, 4 in series would be depleted at 12 volts. Our trucks low limit is 10 volts, so we would have to pay attention to the total pack voltage and re-charge at something above 312 volts.
Of course, most of these problems could be solved if a new battery and charging algorithm could be written into our BMS. I have no clue how to do that.
The main motivator here is price and range. A 120 amp hour pack made up of 4,160- 18650's will fit in out battery box. The easy to find price of an 18650 is between $3.50 to $6.00 each. However, I know of a pallet of 20,000 cells that just sold for $1.00 each. These were genuine LG HG2 18650's at 3000mah. If I had the answers to the issues I've posted here I would have bought 5000 of them.
Kevin McMullin _______________________________________________
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