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12v Battery last 2x as long, weights 6 lbs


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It appears this could be a nice replacement, if it works out as stated in the proposal. One of the big issues will be getting prices down. The big advantage, it appears this battery would have prevented the 12V battery issues that have plagued (at least some) the C-Max.

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It appears this could be a nice replacement, if it works out as stated in the proposal. One of the big issues will be getting prices down. The big advantage, it appears this battery would have prevented the 12V battery issues that have plagued (at least some) the C-Max.

 

10 Ah. and 6lbs lol

 

Li Ion 12v battery I am running now in my cmax is 22Ah and 3lbs. Next one will be ~35Ah and 5 lbs.

Doesn't even need supercaps. I tested it starting my 1999 Corolla 5x in a row, didn't get hot at all.

These batteries will likely not prevent the no start issue associated with the battery drain on certain C-Maxes as the RC and Ah ratings of such batteries are likely significantly less than the OE Motorcraft BXT-67R.   Note:  "Sensing and control for the auto shutdown and wake up process (eg preventing a dead battery)  is working on the bench for our primary test car, but still needs to be integrated to the rest of the design and tested on more cars." - C-Max is not like most cars as Paul indicated. 

 

IMO, get the Ah rating up by a factor of 5-10 X and perhaps the battery will be able to withstand the C-Max parasitic drain so that the C-Max will start the next morning after shutdown the previous day. ;)  Of course this would only mask the dead battery issue.  Hopefully, the latest reprogramming update by Ford has fixed the issue.

Edited by Plus 3 Golfer
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These batteries will likely not prevent the no start issue associated with the battery drain on certain C-Maxes as the RC and Ah ratings of such batteries are likely significantly less than the OE Motorcraft BXT-67R.   Note:  "Sensing and control for the auto shutdown and wake up process (eg preventing a dead battery)  is working on the bench for our primary test car, but still needs to be integrated to the rest of the design and tested on more cars." - C-Max is not like most cars as Paul indicated. 

 

IMO, get the Ah rating up by a factor of 5-10 X and perhaps the battery will be able to withstand the C-Max parasitic drain so that the C-Max will start the next morning after shutdown the previous day. ;)  Of course this would only mask the dead battery issue.  Hopefully, the latest reprogramming update by Ford has fixed the issue.

 

 

The factory battery is about 27 Amp Hour.

My next li-ion battery, I will use 14p so it will be about 43 Amp Hour and about 6 lbs.

 

Note that lithium are more efficient then lead acid - they put out more energy for the same Ah rating.

 

You are right about the electronics, but that is a poor bandaid for a problem that should be fixed directly. I know the Energi does not have this issue.

 

You can also just keep a small 4s lithium ion battery in the glovebox charged to 14.4V for jump starting the car. A small 1-2 lb battery would be fine. This is what I do.

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The factory battery is about 27 Amp Hour.

My next li-ion battery, I will use 14p so it will be about 43 Amp Hour and about 6 lbs.

 

Note that lithium are more efficient then lead acid - they put out more energy for the same Ah rating.

 

You are right about the electronics, but that is a poor bandaid for a problem that should be fixed directly. I know the Energi does not have this issue.

 

You can also just keep a small 4s lithium ion battery in the glovebox charged to 14.4V for jump starting the car. A small 1-2 lb battery would be fine. This is what I do.

 

So do you make these battery packs yourself ?  How do you avoid overcharging and fires ?

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So do you make these battery packs yourself ?  How do you avoid overcharging and fires ?

Don't need to do anything to avoid overcharging - the car only applies 14.4V. That's about 45% charge.

There are excursions to about 15.3V, but that's still not even fully charged.

Yeah I make them .

 

The only risk for fire is physical impact on the cells longitudinally... not a concern at all.

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Don't need to do anything to avoid overcharging - the car only applies 14.4V. That's about 45% charge.

There are excursions to about 15.3V, but that's still not even fully charged.

Yeah I make them .

 

The only risk for fire is physical impact on the cells longitudinally... not a concern at all.

 

So assuming 3.7 volt batteries, I calculate that you string about 9 in series, and some number of these packs in parallel.

 

One concern for which you may have a good understanding

 

from Wikipedia:

 

Consumer-grade lithium-ion batteries should not be charged at temperatures below 0 °C (32 °F). Although a battery pack may appear to be charging normally, electroplating of metallic lithium can occur at the negative electrode during a subfreezing charge, and may not be removable even by repeated cycling. Most devices equipped with Li-ion batteries do not allow charging outside of 0–45 °C for safety reasons, except for mobile phones that may allow some degree of charging when they detect an emergency call in progress

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9 in series?!?

No, 4 in series. That comes to 14.4V/4 = 3.6V per cell.

I am going to modify the charger when the car is plugged into 110V (energy) so that the 12V is charged to ~15.4V (3.85V per cell or ~70%) To get a little more range.

 

Charging below 0C is a concern, however not so much in Houston.

I do have a plan to address this, however it may be okay on it's own because the car apply such a low voltage (i.e. 3.6V per cell)

 

When the cells are cold, their internal resistance rises dramatically, so when the Dc/Dc applies 14.4 v, they will only take a very slow charge anyway if they are dead (~3V/cell)

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