Rx400h Battery Question

[golfpro646]

I own an RX400h and when you go to the screen that shows you how the movement of the car and when it charges. I have noticed that the battery is never fully charged. What can I do to try to get it almost fully charged? Is there a way when driving to charge it up almost all the way?

[RX400h]

You can get fairly close by rolling down a long hill with no AC or seat heaters, but I doubt many here see a full charge status too often.

[SOMEONE ELSE'S GOT MY NAME]

Even when the battery ICON is filled (completely green) . . . that does NOT mean that the battery is filled. The ECU's are set up to never let the traction batteries get below 20% state of charge (SOC) and never let 'em get above 80% SOC. Being set up this way allows the traction batteries to achieve maximum life expectancy, where the manufacturer can guarantee a minimum of 100,000 miles / 150,000 miles - depending on which state in the U.S. that you live in.

The battery icon, when filled simply means you're at 80% SOC. Similarly, when the icon is empty, your battery still has a 20% SOC. That said, your battery regeneration is a process that simply lets you store energy that would otherwise be lost in a conventional ICE, for example, when you're going down hill (after a long hill climb), or when you brake. Idealy, you want to NOT be completely full ... you do NOT want to have to be generating surplus power back to the battery. That's because if you're icon shows full, your energy use isn't being maximized. When your battery is 2 or 3 pips down, THAT's when you are achieving optimum MPG. If your car is having to 'store' energy, it may be because you're applying the brakes because of not anticipating traffic flow, when your drive would have been more eficient by going slower, where you wouldn't have had to hit the brakes.

When your battery icon shows completely full, and you're still going down hill / regenerating, the synergy system is actually set up to 'discharge' the battery, in order to insure that the battery doesn't charge up beyond the 80% SOC.

[ilovelexus2007]

I own an RX400h and when you go to the screen that shows you how the movement of the car and when it charges. I have noticed that the battery is never fully charged. What can I do to try to get it almost fully charged? Is there a way when driving to charge it up almost all the way?

FYI: I posted another message identical to this.

http://us.lexusownersclub.com/forums/index...showtopic=47076

I have to same problem too, my battery never full, only 3/4 full. The folks on the board said it's normal, so I guess we're fine :P

[RolandB]

I own an RX400h and when you go to the screen that shows you how the movement of the car and when it charges. I have noticed that the battery is never fully charged. What can I do to try to get it almost fully charged? Is there a way when driving to charge it up almost all the way?

My experience also has been that you must be 'rolling' downhill for some time. I have experienced 100% only a couple of times but have made it to 7/8ths frequently even last evening while driving after dark. The A/C will have a good draw which will usually prevent the 75%+ indication (light green).

[Jim Clark]

We rarely see the light green bars. I don't think I've ever seen bars all the way to the top. The other day I really stomped on it from a stop with both electric motors kicking in big time. I was surprised how much the charge had gone down after I did this, probably went down two bars.

They have programed it to not allow it to charge too much or too little as either could damage the batteries. Normal is 60-75%.