451 ED HV Battery Removal

This job isn’t to be taken lightly. You will need some specialist equipment but it can be done at home in your garage if you really have to.

Step 1 is that you have to lift the car high enough so you can get the battery out on some sort of trolley. If you have a vehicle lift, that’ll be much easier as you can rest the battery on a trolley, rolling table or large tool cabinet and then lift the car away from the battery.

Since most people don’t have a lift, I bought 4 ramps, jacked up 1 side of the car, placed the ramps in back to front, repeated on the other side to be left with a lifted car that has room at the side to slide the battery out. I bought the plastic ramps as they are lighter.

Katsu Standard (these are the ones I bought)
Katsu V2
Sealey CAR3000C
Durhand (these come apart for easier storage)
DKIEI

It confuses people how it got up there.

Before you do anything regarding the HV battery, you must disconnect the HV battery service plug. Also disconnect the battery negative. You can do it from the battery end or the body end but the body side is easier. Tape it up to stop it from possibly touching and arcing.

Remove the front undertray by taking out the marked fixings.

You’ll find a mess of wires and hoses. Most of this is cooling for the battery. The ED has 2 pumps.

Remove the side skirt…

…and you see the battery side impact protection bar.

It’s covered by a protective piece of plastic. Remove the screws and plastic pins…

…so you can remove them from both sides of the battery.

Look into the side impact protection holes nearest the edge and remove all 3x 10mm nuts.

You now have 5 recesses on the inboard side of the side protection bar, however, only 3 of them are populated with Torx E12 bolts. Remove them.

This is what you’ll have removed from each side.

Look under the car and the HV battery will be very obvious, look at the nearside rear of the battery for the BMS connector. Press in the tab and fold the connector arm over to disconnect it.

Over on the offside rear of the battery are 2 connections. The high voltage DC connector and the battery breather pipe.

Let’s get the breather hose out of the way first. Push the pipe in, pull the collar back and pull the pipe out.

Now we have better access to the HV DC connector. Get yourself a 10mm socket on a ratchet…

…and simply unscrew it.

The connector will drop down out of the way.

This is the battery end of the connector. Because the 12v battery is disconnected and the HV service plug is removed, there will be no voltage to this connector. The terminals have plastic ends to reduce the change of you accidentally touching both.

Look at the front of the batter on the same side, Using a 10mm socket, disconnect the battery case earth cable.

Now it’s time to make a mess. The battery is liquid cooled so we have to disconnect the coolant pipes. Use some pliers to release the tension on the hose clamps so you can pull the hose off the battery.

If you take an empty 5 litre container and cut a hole in the side, it makes a good catch can for all of the coolant that’s about to spew out.

Open the coolant reservoir cap to release the vacuum.

The escaping coolant will speed up and eventually stop.

The next special tool you’ll need is the “some sort of trolley” mentioned earlier. I went for a scissor transmission jack because it’s what I had on hand. A better option would be a lifting table or a pallet jack (pump truck). It should be pointed out that the transmission jack is really not the correct tool for this since the battery is heavier than the jack’s rated capacity and the head of the jack is fairly small so not much of the battery is supported.

Draper 09021 (this is the one I bought).
Draper 53095
Sealey TJ150E

However, I have had 500kg on this jack before despite being rated for 150kg. I wouldn’t crawl around underneath anything it has lifted but it worked fine to lower the battery down in a controlled manner.

Put in your trolley of choice and lift it so it takes the slack a little bit.

All around the perimeter of the battery are E12 bolts.

Remove them all…

…from all the way around. I would recommend doing the side bolts last as you don’t want to be reaching far under the battery when you remove that last fixing.

Lower the trolley down and slide the battery out from under the car.

Refitting is the exact reverse of removal except you are also now fighting gravity. Because of the weight of the battery, I couldn’t get it back in place using the transmission jack. What I did was buy a pallet truck.

Loadsurfer Pallet Truck

When you refill the coolant, if you have MB Star, you can activate the pumps using DAS. If you don’t have MB Star, you’ll have to vacuum fill the cooling system and top it off as the car is turned on.

How Heavy Is The Battery?

I didn’t have a scale suitable to weigh it so I was glad it had a warning label on the side.

178 kilograms. Thats 392 pounds in nonsense American units. That’s bloody heavy!