If your battery is going flat within 15 minutes of using a stereo with the engine off then I doubt your battery is very healthy
Yours is a 500x ?.... which has, say a 60 or 70AH battery... which roughly (on paper) equates to you pulling north of 200A (continuously) for 15 minutes on a fully charged battery before depleting it. (music obviously isn't a constant load and it won't be anywhere near 200A)
so I totally agree, your battery is not healthy. I'd spend your money on a new battery.
I have a battery tester, which says the battery is 90% health. So it is fine.
Someone else was in the car listening to music, with lights on, and aircon i believe. While i mucked around with wheel arches outside etc.
Hmm? Listening to the music WITH LIGHTS ON and AIRCON? So, if headlights, that's going to pull quite a bit of current? But for aircon to be working the engine must be running or the compressor couldn't work? So the alternator must be charging to a greater or lesser extent? I'm confused.
Hi Anthony, I've just picked up on this thread - was working late getting a project in my garden finished off yesterday before the rain promised for today. And it's raining right now! Anyway, Can I ask what your battery tester is? I've been looking into buying one of these myself and have come across a number of reviews which seem to say that basically, there's a lot of cheap ones out there which don't give reliable results. Maybe it's telling you the battery is fine when it's actually not?
I'll ping
@Pugglt Auld Jock , who i believe might know about the super capacitor item i'm trying to recall.
Consider me "pinged"!
This is the one I bought:
https://www.argos.co.uk/product/4198774 It's one of the largest capacity ones you can buy at a reasonable price - claims to be able to start up to 8 litre engines - I've now used it three times "in anger" The first was to start a SEAT Ibiza which was only managing to "click" it's solenoid. The pack charged up quickly and fully from the partially depleted battery and started the car quickly. That was back in May, a month or so after I bought the Pack. Then, a bit later, My pal with the Jag asked for a jump, again! I've known this chap for many years, he worked in motor finance and is a handy guy to be friends with, so I humour him. He's retired, like me, and goes off on "adventures" abroad leaving the car standing for weeks at a time in his driveway, of course it then won't start when he wants it. I've had lengthy conversations with him about maintenance charging etc, but he just says, Yes, but you always get it going for me Jock! I really don't mind helping him out when needed, it usually takes all of half an hour out of my day and causes me no problems. Anyway, he was in a hurry, as usual, so I didn't check battery voltage, just clamped the packs leads to the battery, pushed the button and the display said it was charging up. I think the battery was pretty low because the solenoid wasn't clicking and the pack took about 7 or 8 minutes to charge. It charged fully so I pressed the button again and he twisted the ignition key and the engine cranked over enthusiastically and fired up almost immediately. Very impressive as it's got quite a biggish engine in it.
The only other one I've done was my friend's Ferris ride on mower. This is a large commercial rear steering three cutter mower _ with a V twin Briggs and Stratton petrol engine which I love because it sounds like a Harley when ticking over. It's actually a machine I know well because I had one for doing large areas when I had the squad of gardeners I've talked about elsewhere. Trouble with mowers is no body runs them through the winter so they end up with flat batteries. The battery on this one was managing to throw the pinion into mesh with the flywheel but then didn't have enough Oomph to turn the engine over. This one interested me because the battery is quite small and was obviously pretty flat - would it be able to charge the quite large capacitors in my jump pack? I didn't have my multimeter with me so couldn't check the actual battery voltage. I think the jump pack was still about 60% charged from the last time I used it - on the Jag. The instructions that come with the pack say to always allow the pack to fully recharge before disconnecting from the vehicle it's just started, so I did that after starting the Jag. Anyway, it charged up just fine from the small, motor cycle type, Ferris battery. Unsurprisingly it had no problem starting the mower at all.
So all is still going well with the capacitor based jump pack. I've been very surprised by how long it seems to hold a charge, being capacitor based I was expecting it to self discharge within just a few days but it seems to hold a useful charge for weeks!
So I'm very pleased with it. You need to bear in mind it's not a long term electricity storage solution like a battery based jump pack. It's likely you'll need to charge it from the vehicle battery before you use it so it's not something you'd buy if you want a powerbank to use with a computer or mobile phone. It's designed specifically to do jump staring and, in my experience so far, it does that very well indeed. So why did I buy this instead of a battery device? Well, I wanted something with considerable capacity - this claims to be able to start up to 8 litre engines. I also wanted to not have to remember to charge it up periodically - I often find myself going to use my cordless devices only to find their batteries are flat because I've forgotten to charge them from time to time - A capacitor based pack charges fully in a very short time, I'm averaging out with the Streetwize at around 4 to 5 minutes I'd guess. I also like that it's potential capacity does not diminish with time because it has no battery to sulphate or degrade. also it has a projected life time around twice that of a battery based device - they claim in excess of 10 years.
Having used it several times now, I'm delighted with it and it's doing exactly what I thought it would. The only reservation I would have, especially if you buy one of the smaller cheaper ones, would be regarding it's ability with diesels. A diesel presents it with a bit of a problem because it has heater plugs which draw a lot of electricity before you operate the starter motor. Larger devices, such as the one I bought here, should cope with smaller diesels but smaller devices may struggle because they just don't have the capacity to operate the plugs/manifold heater and then still have enough left to turn the engine over. Also, it requires the "flat" battery to still have some charge in it for it to work. In most circumstances this is not going to be a problem because few "flat" batteries are truely "flat" and will likely still have sufficient voltage in them to charge the pack (I've detailed how this works in a previous thread which I'll post a link to at the end of this). It's worth being aware that it's very unlikely any of the smaller "glovebox" type battery based jump packs would be able to start a vehicle with a deeply discharged battery either.
If you want to read more, here's a link to the thread I started back when I was first thinking of buying one:
https://www.fiatforum.com/threads/jump-starters-and-jump-starting.515632/ I'm no "expert" on this subject but have researched them more than most, I would guess, and have many years experience of jump starting vehicles. So if you want to ask a question please do go ahead.
EDIT. In addition to the above. If you run into a situation where the vehicle's battery is really so flat it's below the threshold (5 volts) where the pack can charge from it then you can safely charge it from another donor vehicle - Say my pal's jag battery was down to just a couple of volts, then I could connect the pack leads to my own vehicle and charge it up from my vehicle's battery. The pack will hold it's charge for several days and the leads are not live after charging until you press the button to initiate discharging so the pack can then be safely disconnected from my own car and reconnected to the car with the flat battery. Press the button and you're good to go! Also there's a USB mains charger which comes with the pack in the box. So, as a last resort, the pack can be charged from the mains. It might take quite some time though, maybe an hour or so id the pack had no residual charge in it. I was interested to see, when I first unboxed mine, that it still had charge in it (I think it was about 40% charged?) and it must have been on a boat from China and then in a warehouse in UK for some time before I received it. So, in most situations, you're not going to be charging from zero.
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