LiPo Battery LTspice model

Thread Starter

dprickett

Joined Oct 8, 2015
4
Does anyone have a simplified spice model for a LiPo battery?
I saw one out there for about $400. I was hoping for free.
 

Thread Starter

dprickett

Joined Oct 8, 2015
4
I need to show it as a load off of a LT3650 charger. I originally put a cap as a load but I don't think that's right. I did see an example representation (attached) but I don't know how to Spice it.
 

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Thread Starter

dprickett

Joined Oct 8, 2015
4
The sense resistor should keep the current around 250mA but I see 2A spikes when I run the simulations. I'm not sure if it's because I use a big cap to represent my battery or it's just my Spice ineptness.
 

MikeML

Joined Oct 2, 2009
5,444
For simulating large (automotive) Lead-Acid batteries, I just use a huge capacitor (100s to 1000s of Farads, not uF) in series with a few hundred mΩ for the impedance. I use a .IC V(bat) = 12.6 V directive as an initial voltage to get the sim started. Beyond that point, the battery is either charging, or discharging as the simulation progresses...

Example here
 

Alec_t

Joined Sep 17, 2013
12,212
I do similar to Mike, but tend to use a lower capacitance (say 1 Farad or less) so that the sim shows some change in 'battery' voltage in a manageable time. BTW, don't fall into the trap that I did and set the value as '1F'. Spice reads that as 1 femtoFarad !
 
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