Car battery jumper pack recommendations

[#1]

---

@Baldrick1 wrote:

... but it occurs to me that this is another battery that will probably need to be recharged from time to time regardless of whether it has been used. ...

---

@Baldrick1 

I just checked mine when I was looking at the instructions (which hasn't been topped up for about 3-4 months) and it said 81% charged.

It would be possible to connect it to a 12V ignition controlled outlet in a car so that it's always charging when the car is being driven, but I'm not sure if that's advisable or not.  Obviously if the car is not driven for months at a time that wouldn't work.

[#2]

@shutter, I know and it’s not an issue but read on.

Thanks @RobPN watched and duly noted.

@Baldrick1 I go Mud Plugging which is why there’s an MP after the Land Rover model above It’s very easy to drain the battery if you swamp the engine so this is a backup to help in those situations.

And for those that don't know what Mud Plugging is have a look at this:

[#3]

That looks like an interesting sport. I can smell the burning clutch plate from here!

[#4]

---

@Baldrick1 wrote:

@Anonymous 

I personally wonder whether it might be worth putting the cost towards the price of a new battery for the vehicle instead.

---

Referring to your previous post about your 9 year old battery......

@Baldrick1 wrote:

@Anonymous 

I can't recommend any as I made up my own. What you need to start your brute of an engine is a pair with decent copper plated as minimum 'crocodile' clips and as thick as possible flexible cables that are fairly short. I must confess that I keep a pair with my spare wheel. The battery seems fine but I am conscious that it's 9 years old. 

Personally I never keep a battery for more than 5 years, and when I fit a new one I write the date it was fitted on the top where it is easily visible with a permanent marker ( use an adhesive sticker if battery is black ) so that I have a quick reference ( or the person who next gets the car does ). about how old the battery is. 

[#5]

---

@RobPN wrote:

---

@Baldrick1 wrote:

... but it occurs to me that this is another battery that will probably need to be recharged from time to time regardless of whether it has been used. ...

---

@Baldrick1 

I just checked mine when I was looking at the instructions (which hasn't been topped up for about 3-4 months) and it said 81% charged.

It would be possible to connect it to a 12V ignition controlled outlet in a car so that it's always charging when the car is being driven, but I'm not sure if that's advisable or not.  Obviously if the car is not driven for months at a time that wouldn't work.

---

It actually damages a lithium ion battery every time you fully charge it,  and they do not like being stored in a fully charged state, in fact for long term storage they are normally kept around 45% charged.  The algorithms on electric vehicles initially limit the charge and discharge envelope to max 80% and min 30% to protect the battery,  and as the battery ages these limits are opened up to preserve range - that is why so many BEV adverts claim 90 minutes to 80% charge or similar ( because fully charging takes LOT longer and also damages the battery ). - Tesla did some tests where the  battery was fully rapid charged pretty much every day and the result was the battery lasted less than 2 years.

http://dolgin.net/Charging%20Lithium-Ion%20Batteries.html

[#6]

But my jump leads cost me next to nothing and by not replacing the battery or buying one of these battery backed devices I’m £60ish up.

I have had new batteries that only lasted 3 years I currently have a good one. If engine cranking gets sluggish then I will immediately change it. If I’m let down again out on the road I have both my jump leads and a breakdown service to call on. For the present, if it’s not.bust then I’m not fixing it.

[#7]

I'm sure these battery pack starters are great if and when you need them.

But it's another battery, and batteries have limited lives. . .

I check the voltage on the car battery fairly regularly. This one is 9 years old, and down to just over 12.4 V when cold and been off charge overnight.

It'll be changed before this Winter.

[#8]

@Anonymous 

I hope the pack works. It says it's good for 20000mAh and a peak current of 800 amps. By my reckoning that's a total reserve of 90 seconds for starting purposes ((20000/1000)/800) hours, which is 90 seconds. Doesn't sound much to me, and that's if the pack battery is perfect. 

[#9]

I don't think these devices work in the same way as a conventional car battery judging by the thickness of the cables which connect to the car battery.  I'll admit to not fully investigating the theory, but think they work in conjunction with the capacity of the battery they are assisting, I don't believe they would work as a standalone replacement for said car battery.  Witchcraft may be involved. 

[#10]

@Anonymous @How much did you pay for your vehicle ? Did it not come with a starting handle....

[#11]

---

@Anonymous wrote:

I go Mud Plugging which is why there’s an MP after the Land Rover model above It’s very easy to drain the battery if you swamp the engine so this is a backup to help in those situations.

---

 If I read things right a 4 litre Range/Land Rover is fitted with a 80Ah battery. These emergency start devices when fully charged come with a 20Ah battery. Consequently it doesn't give you an awful lot more cranking capacity.

[#12]

Can't really tell you that as it's been built from bits over time. But there is a hole for a cranking handle in the chassis but no where to connect it to a push start's not an option either as you inevitably slip on the mud and end up face down in it.

[#13]

---

@RobPN wrote:

I don't think these devices work in the same way as a conventional car battery judging by the thickness of the cables which connect to the car battery.  I'll admit to not fully investigating the theory, but think they work in conjunction with the capacity of the battery they are assisting, I don't believe they would work as a standalone replacement for said car battery.  Witchcraft may be involved. 

---

My thoughts exactly - those puny cables and the socket they plug into would act like a fuse if you tried to pass any appreciable current through them, especially the 800 amps claimed, even for a very short time.  I think they transfer some power to the vehicle battery.

[#14]

For the mud plugging thing, would it not be better to have two identical batteries, split charging and isolators for both batteries, allowing the batteries to be used in turn for "service" while the "standby" one gives a "reserve"?

Just thinking really.

[#15]

That’s an idea @Minesaping, but you want to keep things to a minimum and not over complicate it. The Land Rover in nothing more than a chassis with wheels, engine, seats and roll cage.