Rx400H Traction Battery Charging On Energy Monitor

[bjp]

Can someone please explain why the traction battery on my 2007 Lexus RX400h never stays fully charged (green on the Energy Monitor)? It always displays 2-3 blue bars (on Energy Monitor); on initial start up every day. Is the traction battery suppose to be fully charged? Does it dis-charge when you keep the car sitting overnight? Is this normal? When can you tell that the traction battery needs to be replaced? Thanks for any information.

[maseace]

It's supposed to be in the blue "normal" region. The system will try to keep it in this charge level "sweet spot". Full green bars can actually cause the system to start the engine to burn off excess charge. Also, the charge bars are actually indicating a window of about 40%-80% charge (not 0%-100% as one would expect), since the system won't let the charge level go outside this range. This is all to protect the battery to maximize its life.

[lemon]

It's supposed to be in the blue "normal" region. The system will try to keep it in this charge level "sweet spot". Full green bars can actually cause the system to start the engine to burn off excess charge. Also, the charge bars are actually indicating a window of about 40%-80% charge (not 0%-100% as one would expect), since the system won't let the charge level go outside this range. This is all to protect the battery to maximize its life.

Starting the engine to burn of excess charge makes no sense whatsoever.

To the original poster, it's perfectly fine if it stays at the top of the blue (two bars from the top of the full gauge). If you start the car with it at full blue and drive agressively so that the engine runs constantly (or if you live somewhere hilly and can regenerate a lot on the way down the hill) you'll see it pop into the green.

[Jim Nazium]

If the traction batteries are deemed by the computer to be "fully charged" (which is more like at 80% capacity), then the computer monitoring the traction batteries will not allow any current to flow from the generator to the traction battery cells. The engine may be needed, depending on the driving conditions (say for example in winter, you require heat to the heater box), or driving up a steep slope (the engine is required to move the vehicle along)... it just that the engines consumed fuel, will not be "recuperated" by the various mechanical devices that converted that energy into electricity which is stored by the traction batteries.

In the four years of ownership, I have only seen once with my own eyes, the graphic display show every single bar indicator lit up (to indicate 100% capacity). If you google, you will find plenty of information as to why rechargeable batteries are never left in a state of being either fully charged or fully depleted. It effects there longevity.

Cheers,

MadloR

[removeum]

I just did it with my RX400h last week. Check out my avatar.

[TBird]

Does anyone know if there is an aftermarket Lithiium battery replacement for my 2008 old technology ni metal batteries? It should be lighter and have greater chance to drive longer on electrics only.

[maseace]

If it existed for the RX400h, it would be over $10,000. A123 Hymotion makes an extra battery to convert Prius to plug-in hybrid, and it's $10,000 for the upgrade/installation.

http://www.hymotion.com/hymotion/products/N5_range_extender

[RX400h]

Does anyone know if there is an aftermarket Lithiium battery replacement for my 2008 old technology ni metal batteries? It should be lighter and have greater chance to drive longer on electrics only.

At this point in time, the life of lithium ion batteries for automotive propulsion is unknown. The life of NiMH batteries is well established with some Prius vehicles surpassing 250,000 miles using the OEM batteries.