Portable jump starter

[Thackeray]

Does anyone have any recommendations for a portable jump start unit? There seem to be quite a number available now for around £30 or so. Are they any good?

My main requirements would be

• a small genuinely portable unit, and
• enough power to get a Lexus hybrid car into the "Ready" state..

[Herbie]

I've got one of these and although I've not yet needed it to start the car, it's been in the boot for about a year and is still holding 75% charge, so I know it'll be there if or when I do need it.

Incidentally, it takes very little power to get the car into the READY state but I wouldn't buy a smaller capacity unit in case someone else with a 'normal' car needs help.

[TigerFish]

I’ve got one similar to the one Herbie linked to (DBPower one). It does up to 6.5 litre petrol engines as I need that for my AMG. Never used it on the AMG yet, but it has started my 2.9 Corrado quite a few times, and worked great.

 

You can get smaller ones (which are cheaper) if you don’t need it to cater for such a big engine.

 

 

Sent from my Iphone using Tapatalk Pro

 

[BrunoLeal]

I bought this one: https://www.amazon.co.uk/dp/B079LZJ8GK/ref=pe_3187911_189395841_TE_dp_2

I've read some reviews and came to the conclusion that is more than enough for an IS300h. Never tried it yet though.

[bernieeccles]

I bought a similar item to that in the first post because of an upcoming Continental trip and not wanting to get stuck if the Battery went flat. It's an auto.

Last week my neighbour came round and asked if I had a Battery charger as her car Battery was flat and it would not start. Great opportunity to try my jump starter I thought.

Plugged in the big leads, clipped them on to her Battery and wow, it actually worked brilliantly.

Still had 95% of charge left in it.

A big thumbs up from me.

[wharfhouse]

3 hours ago, Thackeray said:

Does anyone have any recommendations for a portable jump start unit? There seem to be quite a number available now for around £30 or so. Are they any good?

My main requirements would be

• a small genuinely portable unit, and
• enough power to get a Lexus hybrid car into the "Ready" state..

I went for a DBPower one - seemed to get good reviews and the power needed to start a hybrid is much less than a traditional starter. Haven't had to use it to date but check it every few months just in case and it holds the charge well. Keep it in the glove box just in case. 

[Thackeray]

Many thanks for all the suggestions. I've ordered the one Bruno suggested. Only £20 on amazon and looks as though it should have enough power to get the hybrid system running. Let's hope it's never needed but at least it's something to fall back on if the car ever fails to start as the winter arrives. If that doesn't happen the device can be used to charge phones while travelling.

[BrunoLeal]

1 minute ago, Thackeray said:

Many thanks for all the suggestions. I've ordered the one Bruno suggested. Only £20 on Amazon and looks as though it should have enough power to get the hybrid system running. Let's hope it's never needed but at least it's something to fall back on if the car ever fails to start as the winter arrives. If that doesn't happen the device can be used to charge phones while travelling.

I've also ordered the travel bag and put it inside the Battery compartment in the booth. 

[Hadrian]

You need to keep the portable starters topped up, as when they've been used a few times, and you leave them without re charging, the Battery

might not take or hold a charge any more.  The cheaper units tend to use cheapo batteries, to replace them with a decent Battery will cost more than

what you payed for the charger in the first place.

That's my experience anyway.

[200h]

if you want something small & portable then this could be what

your looking for & it also has other uses

https://www.ebay.co.uk/itm/8000mAh-300A-12V-USB-Car-Jump-Starter-Pack-Booster-Battery-Charger-Power-Bank-UK-/202345220490

 

[Thackeray]

20 hours ago, 200h said:

if you want something small & portable then this could be what

your looking for & it also has other uses

https://www.ebay.co.uk/itm/8000mAh-300A-12V-USB-Car-Jump-Starter-Pack-Booster-Battery-Charger-Power-Bank-UK-/202345220490

 

Yes, that looks good, too. In fact, it looks as though it may be the same product with cosmetic changes as the DBPower one on Amazon. The output ratings are the same, the crocodile clips are the same, the labelling is the same, though the socket positions have been changed.

Maybe you get a better Battery technology for the £9 higher price. It's hard to tell from the descriptions.

[Anatoliy]

On 10/29/2018 at 1:58 PM, Thackeray said:

Does anyone have any recommendations for a portable jump start unit? There seem to be quite a number available now for around £30 or so. Are they any good?

My main requirements would be

• a small genuinely portable unit, and
• enough power to get a Lexus hybrid car into the "Ready" state..

Hi,

I personally would not buy jump start untill fully understand your car requirements of correct power for jump start. My previous Lexus GS450H run out of Battery (I left lights on on the rush), my friend  offered jump start but as AA was only 30min away, I refused his help. When AA arrived they said:*do not jump start hybrid system without proper professional jump start equipment and knowing exact voltage required. If i not mistaken, comnected computer showed them that 430v requires to start the car.

 

 I then asked Lexus service departmentand they confirmed - be carefull when jump start as it may “destroy” your car. It may cause huge issue between your hybrid system and CVT gear box! (Cost for repair - £8000 by Lexus)

AA is free for me (benefit from bank) and it doesn’t take long for them to arrive. 

 

Just a personal opinion....

[200h]

jump starting is a term used for starting a vehicle with a flat Battery

you dont jump start a hybrid you power up the computers

this enables the hybrid Battery to turn the engine over and start it

hybrid batteries generally dont go flat ,the 12v accessory battery 

is the one that will go flat and this is the Battery that is being assisted

by the external power source.

in the lexus user guide there are no warnings to scare you

or advising that your lexus dealer should be given the opportunity to fleece you

for something you can quite easily do yourself.

[Herbie]

3 hours ago, Anatoliy said:

 I then asked Lexus service departmentand they confirmed - be carefull when jump start as it may “destroy” your car.

It is indeed possible to do some damage if you connect the 'fresh' Battery with the wrong polarity, but there is no danger whatsoever in putting a good 12V supply in parallel with a flat 12V Battery as long as you connect it correctly. It's just a 12V source like the one that's already there.

[DanD]

I guess that, if in doubt, refer to the owner's handbook: I'm sure I saw it documented in there.

[wharfhouse]

RTFM... same procedure as any non-hybrid car...

[200h]

Phil you read my mind

i was just in the middle of getting those pages uploaded

[Thackeray]

I'm confused by the manual saying the point of running the engine of the other vehicle for five minutes is to charge the flat Battery on your vehicle.

I always thought that when jump starting a car you kept the engine running in the second car so that you didn't end up with its Battery being flat too. Running the engine for just five minutes doesn't seem long enough to recharge the flat Battery on your car. Once you'd got a conventional car running, people always used to say you shouldn't turn it off and it was best to go for a half-hour run to recharge the Battery before you tried to start the car again.

Why wouldn't you just connect to the second car, start its engine, and then immediately start the hybrid car? Isn't the power coming from the second car's Battery sufficient to get the first car's hybrid system to the Ready state? 

[wharfhouse]

1 minute ago, Thackeray said:

I'm confused by the manual saying the point of running the engine of the other vehicle for five minutes is to charge the flat battery on your vehicle.

I always thought that when jump starting a car you kept the engine running in the second car so that you didn't end up with its battery being flat too. Running the engine for just five minutes doesn't seem long enough to recharge the flat battery on your car. Once you'd got a conventional car running, people always used to say you shouldn't turn it off and it was best to go for a half-hour run to recharge the battery before you tried to start the car again.

Why wouldn't you just connect to the second car, start its engine, and then immediately start the hybrid car? Isn't the power coming from the second car's battery sufficient to get the first car's hybrid system to the Ready state? 

I have always run the car doing the jump starting for 5 minutes on conventional engines when doing a jump start before starting the car with the flat Battery - IMHO just makes sure everything is stabilised and there is some charge in the flat battey - then left them connected for 5 to 10 minutes and disconnected. 

[ColinBarber]

On 11/1/2018 at 8:40 PM, Anatoliy said:

When AA arrived they said:*do not jump start hybrid system without proper professional jump start equipment and knowing exact voltage required. If i not mistaken, comnected computer showed them that 430v requires to start the car.

That would be the on very rare occasion that the hybrid Battery had completely discharged, at which point the only thing the AA would be able to do is transport your vehicle to a Lexus dealer.

If you have a flat 12v Battery then the procedure is no different than any other vehicle with a 12v electrical system, other than you don't need to really worry about large duty cables as the current drawn to get the vehicle 'Ready' is very low.

[Thackeray]

23 hours ago, ColinBarber said:

If you have a flat 12v battery then the procedure is no different than any other vehicle with a 12v electrical system, other than you don't need to really worry about large duty cables as the current drawn to get the vehicle 'Ready' is very low.

Thanks for the explanation. It's what I assumed was the case. Are there any other concerns about using a portable jump start device instead of a second car with its engine running? I don't know very much about the details of car electrics but I would assume that a device the size of an Iphone would have less capacity to harm a hybrid vehicle than connecting it to another car with a full-size 12v Battery, backed up by (let's say) a five litre engine driving its alternator.

(Incidentally, the yellow DBPower one recommended above, which I have bought, is reduced in price on Amazon to £16.99 for the next three and a half hours. Looks a good price for this item.)

[ColinBarber]

23 hours ago, Thackeray said:

Are there any other concerns about using a portable jump start device instead of a second car with its engine running?

It is probably actually safer than jump starting off another vehicle.

There is a risk of a voltage spike from the alternator of the running vehicle which can damaged the electrics on both when jump starting. For a hybrid I wouldn't actually start the engine of the vehicle being used to provide the voltage - as the hybrid vehicle doesn't require high energy to get it 'Ready' there is no risk of flattening the other vehicle's Battery so no need to start it.

[DanD]

19 hours ago, ColinBarber said:

It is probably actually safer than jump starting off another vehicle.

There is a risk of a voltage spike from the alternator of the running vehicle which can damaged the electrics on both when jump starting. For a hybrid I wouldn't actually start the engine of the vehicle being used to provide the voltage - as the hybrid vehicle doesn't require high energy to get it 'Ready' there is no risk of flattening the other vehicle's battery so no need to start it.

Even though that is what the owner's manual recommends - as per above post?

[Herbie]

On 11/7/2018 at 2:48 PM, DanD said:

It is probably actually safer than jump starting off another vehicle.

There is a risk of a voltage spike from the alternator of the running vehicle which can damaged the electrics on both when jump starting. For a hybrid I wouldn't actually start the engine of the vehicle being used to provide the voltage - as the hybrid vehicle doesn't require high energy to get it 'Ready' there is no risk of flattening the other vehicle's battery so no need to start it.

 

On 11/7/2018 at 2:48 PM, DanD said:

Even though that is what the owner's manual recommends - as per above post?

Absolutely. It seems to me that some folks on here are overthinking this. 

If it was a 'standard' car with a standard starter motor then you would need a big beefy Battery to jump start it because an average starter motor draws a current of about 300A to crank the engine.

A hybrid car doesn't use a standard starter motor as we know it. The 12V Battery in a hybrid is used to power the entry/exit systems and the computers that boot up to bring the car to the READY state. As you can see in the photo below my clamp meter is showing that the 12V Battery is supplying a current of 15.32A with the car in the READY state, which is a hell of a lot lower than the 300A required for a traditional starter motor.

Given that, I think we can safely say that in this context, a 12V source is a 12V source, whether that be from a Battery or a portable jump start device.

[Martin F]

Out of interest, did you monitor the current when the engine started?