Flat Battery - Abandoned hope?!

Richie_W · May 30, 2020

Hello guys. Hoping you can help
The wife's RX450H has been sat on the drive for a long time due to Covid-19 lockdown. Just went to move it and it is completely flat.

I have read the manual and looked on youtube.

I cannot jumpstart this, as the nearside wing is against the side of the house and jump leads are not long enough
I cannot get into the boot to charge the Battery as it is flat and the boot won't open!
There doesn't seem to be any solution for the scenario if you don't have something to jump it from...

Is there a way to get into the boot please, so I can charge the Battery? If not, will I damage something by hooking a charger up to the positive terminal at the front in the fuse box (and where will the negative go if I do this?!)

Any help will be much appreciated

Richie

Brian26 · May 30, 2020

Hi Richie, Would connecting two sets of jump leads reach? ( I have done this on occasion to start a 'conventional car ') Just have to be careful not to short circuit them. As the Lexus only requires a small current to boot the computers you may be able to start it that way or it should provide enough current to open the tailgate.

Bri

NemesisUK · May 30, 2020

Is there no mechanical key to open the tailgate?

Herbie · May 30, 2020

23 minutes ago, NemesisUK said:

Is there no mechanical key to open the tailgate?

Not on my 2013 RX450h there isn't. Well, there's a mechanical key for the front doors but no key barrel to insert a key on the tailgate.

Herbie · May 30, 2020

1 hour ago, Richie_W said:

If not, will I damage something by hooking a charger up to the positive terminal at the front in the fuse box (and where will the negative go if I do this?!)

If you can get at that, why can't you use jump leads on it?

EDIT - because they aren't long enough now that I've just re-read your original post.

Can't you just use some bits of wire or mains flex or something to extend your jump leads? You don't need to pass hundreds of Amps like a conventional car, less than 20A will get the car into READY mode, but even less will provide enough power to at least unlock the doors and hopefully the tailgate.

EDIT 2 - if you've used the mechanical key to unlock the doors, can you not just climb over the back seats to get to the tailgate release mechanism if there is one. Or maybe even use the shift lock to get the car in N, parking brake off and just push the car away from the wall, closer to the jump leads?

NemesisUK · May 30, 2020

Can you open any of the doors and get into the load space? If so the handbook shows how to open the tailgate from inside

Richie_W · May 30, 2020

1 hour ago, Brian26 said:

Hi Richie, Would connecting two sets of jump leads reach? ( I have done this on occasion to start a 'conventional car ') Just have to be careful not to short circuit them. As the Lexus only requires a small current to boot the computers you may be able to start it that way or it should provide enough current to open the tailgate.

Bri

Sadly only have one set, but the idea did cross my mind Bri!

Richie_W · May 30, 2020

36 minutes ago, NemesisUK said:

Is there no mechanical key to open the tailgate?

No, just the electronic latch

Herbie · May 30, 2020

Just now, Richie_W said:

No, just the electronic latch

Richie_W · May 30, 2020

32 minutes ago, Herbie said:

If you can get at that, why can't you use jump leads on it?

EDIT - because they aren't long enough now that I've just re-read your original post.

Can't you just use some bits of wire or mains flex or something to extend your jump leads? You don't need to pass hundreds of Amps like a conventional car, less than 20A will get the car into READY mode, but even less will provide enough power to at least unlock the doors and hopefully the tailgate.

EDIT 2 - if you've used the mechanical key to unlock the doors, can you not just climb over the back seats to get to the tailgate release mechanism if there is one. Or maybe even use the shift lock to get the car in N, parking brake off and just push the car away from the wall, closer to the jump leads?

Hi Herbie. Think I will go for the releasing the tailgate from the inside option 🙂. Thanks

Richie_W · May 30, 2020

Our first time on this forum and thank you for your suggestions. I will do the releasing from the inside tomorrow and then charge the Battery.

Thank you for your help - much appreciated. Stay safe

Richie

m4rkw · May 30, 2020

After coming back to a dead car at airports a couple of times I now have a Halfords jumpstarter in the glovebox. Saved me a couple of times now.

Herbie · May 30, 2020

Just now, m4rkw said:

After coming back to a dead car at airports a couple of times I now have a halfords jumpstarter in the glovebox. Saved me a couple of times now.

Yep, me too. Well worth every penny just for peace of mind (although I got a DB Power one rather than Halfords 🙂)

Herbie · May 30, 2020

1 hour ago, Richie_W said:

There doesn't seem to be any solution for the scenario if you don't have something to jump it from...

As mentioned above by m4rkw and myself, these things are brilliant for situations like this - jump leads are just so last century :laughing:

1 hour ago, Richie_W said:

If not, will I damage something by hooking a charger up to the positive terminal at the front in the fuse box (and where will the negative go if I do this?!)

The Battery negative is strapped to the car body so literally any unpainted bolt, nut or screw that's not insulated from the body will do.

m4rkw · May 30, 2020

I jumped my car from another car a couple of times before I learned how dangerous it is to do it directly on the Battery terminals. A charging Battery can emit flammable gas, and when you attach the negative lead with the positive connected you can get sparks. It's not uncommon for the gas to ignite and start a fire - not a pretty sight.

Avoid this by always using a ground point as far away from the Battery as possible. The advantage of the portable jump-starters is that they know when they're connected and so don't supply cranking current until they are so are much safer.

Herbie · May 30, 2020

13 minutes ago, m4rkw said:

I jumped my car from another car a couple of times before I learned how dangerous it is to do it directly on the battery terminals. A charging battery can emit flammable gas, and when you attach the negative lead with the positive connected you can get sparks. It's not uncommon for the gas to ignite and start a fire - not a pretty sight.

Avoid this by always using a ground point as far away from the battery as possible. The advantage of the portable jump-starters is that they know when they're connected and so don't supply cranking current until they are so are much safer.

I know what you're saying Mark and I agree - better to be safe than sorry and all that.

However, I must take issue with your statement that "it's not uncommon".

In more than 45 years of personally driving, messing with jump leads, doing all my own maintenance etc., talking to friends and family about it, and also talking to the mechanics in the BT garage and also a mate of mine who is a mechanic in the NW Ambulance Service garage, not a single one of us has ever had it happen to us personally, nor does anyone know someone who has had it happen to them.

Of course, we should stick to the rules and I'm not telling anyone to do otherwise, but "not uncommon"? I'd say it's about as uncommon as an uncommon thing on World Uncommon Day to be honest 😄

m4rkw · May 30, 2020

Ok bad choice of words - I've heard people talk about it happening but you're right it's probably quite uncommon.

Spottedlaurel · May 30, 2020

Could you jump it from a loose Battery, so you don't need to worry about getting another car close to it?

Mine went flat several weeks ago, but 'luckily' just enough to mean it wouldn't start but I could get into the boot etc. Not having a reliable set of jump leads and being frustrated that a £75 charger I bought didn't work, I got the AA round. He jumped it OK but said the Battery was in need of replacement, However it's been fine since I've used the RX more regularly again.

Maybe something to watch for in the winter, but I'd like to avoid spending £200 right now if I can.....

Barry14UK · May 30, 2020

If jump leads too short could you not just borrow a charged Battery to connect to jump leads to get boot open or get rescue service AA, RAC or whoever to help?

Barry14UK · May 30, 2020

You just beat me to it Nigel.

PCM · May 31, 2020

12 hours ago, Richie_W said:

Our first time on this forum and thank you for your suggestions. I will do the releasing from the inside tomorrow and then charge the battery.

Thank you for your help - much appreciated. Stay safe

Richie

Good luck.

Let us know how you get on ...

Lydiamight · May 31, 2020

Why not invest £25.00 in one of these? https://www.ebay.co.uk/itm/264728750368

m4rkw · May 31, 2020

22 minutes ago, Lydiamight said:

Why not invest £25.00 in one of these? https://www.ebay.co.uk/itm/264728750368

My immediate gut reaction to that is “not touch with barge pole”, but i’m open to being persuaded otherwise!

royoftherovers · May 31, 2020

23 minutes ago, Lydiamight said:

Why not invest £25.00 in one of these? https://www.ebay.co.uk/itm/264728750368

Had one for years Ray.

1 minute ago, m4rkw said:

My immediate gut reaction to that is “not touch with barge pole”, but i’m open to being persuaded otherwise!

Your gut reaction might just lead you astray Mark!

royoftherovers · May 31, 2020

13 hours ago, Richie_W said:

Our first time on this forum and thank you for your suggestions. I will do the releasing from the inside tomorrow and then charge the battery.

Thank you for your help - much appreciated. Stay safe

Richie

Why not just attach the Jump Leads to the Positive point in the Engine Bay and any Body Part ??????????????????????