Portable Jump Starters. Anyone got any experience or views?

pongoglo

pongoglo

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Im moored on a cheapish pontoon without shore power which during winter can be a real pain. Despite having a solar panel in an attempt to keep the battery's topped (it is only 5W..) I frequently come down to the vessel to find not enough 'oomph' left in the battery's to make her turn. I tried one of those cheapish Maplins jumpstart's without any joy, I think it only has about 400 CCA, and a 12AH battery, and it made no difference at all. Last weekend however in desperation I used a neighbour's top range Halfords job and she turned no prob and fired first time, so obviously my Maplins jobby is lacking in CCA. Does anyone have any experience, recommendations? I am thinking I probably need about 800 CCA and a 20AH battery, but they are quite pricey so I don't want to get it wrong. My engines a BMC 1.5. Thanks in advance!
 
I had a Halfords one in 2006 and used it to start the car a few times without any problems. Also used it to run a few 12V things on the boat over the years. I think you get what you pay for in general. IIRC it was a 20Ah battery.

Just like all batteries, you have to keep it charged properly when not used for a while.

How do I know? :)
 
Hi pongoglo,

I have an emergency powerpack but it is on the boat and I can't remember the make and model. Luckily I have a wind generator on my boat that keeps my batteries charged enough to start my engine. It doesn't take much charge to enable a good set of batteries to turn-over a diesel so there is a possibility your batteries may not be holding their charge or they have insufficient CCA. either way it may be worth having them checked as they may need replacing.

I have left my boat with batteries in a low state of charge (will not turn the engine) and when returning a week later the batteries are charged sufficiently to easily start the engine. Unfortunately I have no experience of solar cells to advise what power would be necessary to achieve the same result.

A backup powerpack can be used in two ways. One way is with a pair of heavy duty cables direct to the starter motor - not via your batteries as they will also draw current. The other is to use the powerpack to charge your boat batteries until they have the necessary charge. The two methods require different types of powerpack as using one to charge your boat batteries requires a higher voltage and, of course takes a little time.

Probably the best solution is to install a dedicated engine battery that is not used for domestics and is therefore always fully charged.
 
It wont be doing your battery any good being left discharged so why not remove it and take it home for a proper charge when you are not on the boat.I know they can be heavy and awkward,but not impossible to get ashore from a pontoon.The alternative is possibly very expensive replacement.
 
Essentially what you are saying is that you lack a proper split charge system. Would it not be easier to do this rather than lug around a wimpy second battery that you will also forget to charge. Stick in a VSR and a second battery and then you will always have charge in your start battery.
 
theoldsalt said:
Hi pongoglo,

A backup powerpack can be used in two ways. One way is with a pair of heavy duty cables direct to the starter motor - not via your batteries as they will also draw current. The other is to use the powerpack to charge your boat batteries until they have the necessary charge. The two methods require different types of powerpack as using one to charge your boat batteries requires a higher voltage and, of course takes a little time.
Click to expand...

Thanks. Yes I have used both methods and find that direct to the starter motor works well. The advantage of the powrerpack is that I keep it in the car, a Landrover Discovery 2.5 TDI, and on the occaisional winter morning it has jumped me fine. Prob is the Maplins job seems to work fine for the car but isnt powerful enough for the boat. presumably because the BMC 1.5 is a much older engine and requires more CCA to turn?. Old or not,she runs fine once she fires. The Powerpack is easily light enough to take home and charge and in theory should cover both functions. Car and boat. I guess my problem is I dont understand the science, how can such a small battery, 20AH weighing in at only 10kg or so generate 800> Amps in cranking power, when a much heavier standard battery can only push some 330 Amps or so?
 
Surely it would be cheaper and far more convenient to buy a bigger solar panel? A 5 watt one in UK in winter cannot be expected to do much for a good sized battery. The 'rule of thumb' for solar panel sizing is 10% without a regulator, e.g. a 10 watt panel for 100 Ah battery. But cheap regulators are not expensive from Maplins, for example, so you could go for a larger panel to ensure batteries are kept in fully charged condition. I used a 38 watt one, with a regulator, for a total of 330 Ah batteries in two banks.
 
The batteries in the power pack are exactly what they are ie small. They are light enough to be taken home for charge. However in starting an engine they can only help your main engine start battery. If it is marginally unable to cope due to discharge or old age your little battery jumper might just make the difference. I would not buy one however. A decent ordinary car battery may be light enough to carry and provide a lot more CCA. However best bet would be a decent engine start battery and a larger solar panel.
Also fit isolation and domestic batteries which could collectively provide enough oopmph to start the engine. good luck olewill
 
I purchased a powerpack because not only does it provide backup for boat batteries but the version I have incorporates an inverter giving me 240v for mains power tools a compressor and a light. The portable 240v supply has been particularly useful for odd jobs on the boat.
 
The Portable Jump Starter I have is totally unsuitable to start a Big Diesel. Great for my neighbours Golf. But you get what you pay for. After all they can only have a Motor Cycle Battery inside.
Although the can come in useful as I blew up my 12v Socket in my car and with nothing to plug in my Sat Nav the Jump Starter worked fine. And I have one of these 12v Wrench Wheel Nut Socket things which is excellent (until you plug it into the car socket) and with my trailer axles 15 ft behind the car I plug the Wrench into the Jump Start thing and 30 seconds later all the wheel nuts are off. But you get what you pay for.
 
theoldsalt said:
I purchased a powerpack because not only does it provide backup for boat batteries but the version I have incorporates an inverter giving me 240v for mains power tools a compressor and a light. The portable 240v supply has been particularly useful for odd jobs on the boat.
Click to expand...

That is one of the factors that is driving me on this, plus the facts that you can use it on both car and boat, plus charge it at home and have 100% confidence that it is fully charged before undertaking the hour and a half drive down to the boat! Thanks for all the useful comments/advice so far, I guess that specifically for the boat my thoughts are now turning more toward one of these:

http://www.tayna.co.uk/Numax-CXV24MF-P3126.html

A Numax CXV24MF. Im looking at the Numax because it seems to offer excellent cranking power 1000 MCA (approx 800 CCA??) as well as 86 Ah deep cycle capability and a guaranteed 500 cycle life. Crucially for me however it has carrying handles built in and is compact enough and light enough to take home and charge plus carry down to the boat if necessary.

vyv_cox said:
The 'rule of thumb' for solar panel sizing is 10% without a regulator, e.g. a 10 watt panel for 100 Ah battery. But cheap regulators are not expensive from Maplins, for example, so you could go for a larger panel to ensure batteries are kept in fully charged condition. I used a 38 watt one, with a regulator, for a total of 330 Ah batteries in two banks.
Click to expand...


In terms of solar panel I do have a charge regulator and am planning to upgrade my panel to 20 Watt when funds permit. Thus I will have 1 x 86 Ah Starter plus 1 x 110 Ah domestic = 196 Ah, hence the very useful 10% rule which I hadn't heard about should work - thanks!.

William_H said:
A decent ordinary car battery may be light enough to carry and provide a lot more CCA. However best bet would be a decent engine start battery and a larger solar panel.
Also fit isolation and domestic batteries which could collectively provide enough oopmph to start the engine. good luck olewill
Click to expand...

Iv'e still got a question about this however, linking in series. To gain extra cranking power do I have to physically link the positive and neg terminals of the two batteries with jump leads or the like, or would merely turning my battery switch to 'both' suffice? Sorry, my physics are ****. A long time since I left school but even then I only narrowly scraped a 'C' in GCSE, although the electrics bit always interested me much more than PH values etc. Anyone remember Ohm's law??
 
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vyv_cox said:
Parallel using the 'both' switch is the normal way to do it. There are occasions when starting an engine on 24 volts can be useful but more of a workshop technique than one to be used at sea.
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Paralleling may be the normal way to do it but I don't think it's a good idea. If you parallel a flat battery with a charged battery, you'll get the equivalent of a half-charged battery which may not have enough grunt to start your engine - then what do you do? Instead of paralleling, you need to substitute the house battery. This is easily achieved by appropriate switching.
 
Do you use our boat over winter?
If not battery removal would prolong their life. I usually remove mine and replace with a retired battery which is good enough for shore use over the winter. Good batteries shouldnt discharge too rapidly - maybe you should examine the battery itself rather than any of the recharge options?
 
To answer your original question - I've had the experience of urgently needing a jumpstart (Alderney, Volvo 2003T, battery charging problem - nuff said) and the powerpack I'd brought along for the cruise repaid every penny.

Incidentally it was a cheapie one, now 9 years old but had enough grunt to start a Toyota Hiace with a flat battery last week.......

I never cruise without it now, and its eventual replacement will be the best I can afford
 
pongoglo said:
That is one of the factors that is driving me on this, plus the facts that you can use it on both car and boat, plus charge it at home and have 100% confidence that it is fully charged before undertaking the hour and a half drive down to the boat! Thanks for all the useful comments/advice so far, I guess that specifically for the boat my thoughts are now turning more toward one of these:

http://www.tayna.co.uk/Numax-CXV24MF-P3126.html

A Numax CXV24MF. Im looking at the Numax because it seems to offer excellent cranking power 1000 MCA (approx 800 CCA??) as well as 86 Ah deep cycle capability and a guaranteed 500 cycle life. Crucially for me however it has carrying handles built in and is compact enough and light enough to take home and charge plus carry down to the boat if necessary.




In terms of solar panel I do have a charge regulator and am planning to upgrade my panel to 20 Watt when funds permit. Thus I will have 1 x 86 Ah Starter plus 1 x 110 Ah domestic = 196 Ah, hence the very useful 10% rule which I hadn't heard about should work - thanks!.



Iv'e still got a question about this however, linking in series. To gain extra cranking power do I have to physically link the positive and neg terminals of the two batteries with jump leads or the like, or would merely turning my battery switch to 'both' suffice? Sorry, my physics are ****. A long time since I left school but even then I only narrowly scraped a 'C' in GCSE, although the electrics bit always interested me much more than PH values etc. Anyone remember Ohm's law??
Click to expand...

I presume and hope you meant parallel rather than series that you wrote. Batteries in series will give 24v which may cause problems with nay other circuit using current. Further if you start an engine with batteries in series you can not revert to 12v without disconnecting the batteries. So parallel it must be.
This means that using jumpers you connect the +ve of one battery to +ve of the other negative likewise. This means that each battery gives what current they can to the starter . Once running you can disconnect the jump battery while leaving the original battery taking the charge.
Regarding leaving the bad battery in circuit this question often comes up. If the bad battery has a definite fault like shorted cell then yes it will suck and waste the power of the good battery. However mostly this is not the case and the jump battery simply assists the bad battery. Most of us have done this with our cars when the battery dies or goes flat. We simply jump another in parallel and usually there are no problems. So for ease and convenience I would always risk it and simply parallel another battery. Which in fact is what we do with 2 battery systems and a "both" switch position. good luck olewill
 
ghostlymoron said:
Paralleling may be the normal way to do it but I don't think it's a good idea. If you parallel a flat battery with a charged battery, you'll get the equivalent of a half-charged battery which may not have enough grunt to start your engine - then what do you do? Instead of paralleling, you need to substitute the house battery. This is easily achieved by appropriate switching.
Click to expand...

I don't agree. This may happen over some hours but in the short term it's what most people seem to do, me included. By all means try switch setting 2 if setting 1 doesn't start it but using setting Both will usually work if the other two on their own don't. I wouldn't mind a pound for every time I have used jumper leads, which is the motoring equivalent of a Both switch.
 
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