Since I changed our car and the 12V to the fag lighter switches off when the ignition is off I need some way to recharge our camping lights etc.
It was suggested to me what I need is a power bank, so I bought a https://www.amazon.co.uk/GOOLOO-Starter-Emergency-Portable-Starters/dp/B07S8B3TSY/........Gooloo GE2000 off Amazon as it has a 12V output socket.
Unfortunately it appears to be way down on its quoted power. It states it is 66 Watt Hours but some testing I did at work suggests it's closer to about 19 watt hours ! Details below just in case I have mad an error in my testing formula etc !
Do the esteemed memnbers of this forum think the unit was faulty or that they are all way down on their quoted power ?
Can anyone suggest any other recommended power banks which may work better?
Test results :
I set up a 17 Ohm load from the unit's 12V output and monitored how long it took to discharge the GE2000.
I calculate a 17 Ohm load at 12V should absorb about 8.5 Watts, though in actual fact the average voltage over the test was about 11.2. But even 11.2V into 17 Ohms should be 7.4 watts.
So, if the GE2000 really does have 66.6 Watt hour capacity it should take 9 hours to discharge ?
It didn't, it was flat in about 2.5 hours, by which time its output was down to only 10.4V (would that actually power a battery charger requiring 12V ? ).
2.5 hours at 7.4 watts is about 19 watt hours, less than a third of its claimed capacity of "66.6 watt hours"......
Also, when recharging it with its 15V x 1.0 amp charger (= 15W), it should take about 4.5 hours the charge (66.6 divided by 15).
It didn't, it reported it was 99% full after only 90 minutes. It never moved from 99% for a good hour after that, but switching the unit off and on at that point brought up 100% so I am assuming that was just a software issue (it may not register 100% whilst charging till it's rebooted ?).
Do the esteemed members of this forum think the unit was faulty [i.e. was my test methodology and conclusions correct ?] or that they are all way down on their quoted power ?
Can anyone suggest any other recommended power banks which may work better?
Quote: Originally posted by seanfdh on 30/6/2023
What do you want to be able to charge and how long do you visualise being off grid?
Rechargeable batteries for our lights, our Lumi Fan USB/Lantern/Fan/Spotlight, plus phones, maybe even a laptop.
We're going away for 5 nights in July.
I know it is possible we may just get away without having to recharge anything in only 5 days, but I'd rather not take the chance !
I have seen power banks with more quoted power (assuming they actually have the power they claim, the GE2000 did not....) but I cannot find one with a 12V output socket.
Quote: Originally posted by trog100 on 01/7/2023
have you looked at the smaller solar power stations.. they may cost more than what you are thinking of spending but they would do the job..
trog
Good idea, but what if the sun doesn't shine ? ! ?
Plus by definition it would have to be used during the day when we may well out and about ? Plus how many of them have a 12V output socket ? One I just looked at just had USB sockets.
TBH the simplest solution would have been to keep my old car !
My 06 plate Focus I got rid of last year kept its 12V (to the fag lighter) and so one could just recharge stuff no problem, even overnight. But my newer car (a 2013 Toyota Auris) switches off the feed to the power sockets when the ignition key is removed. An absolute PITA !
I was just checking up on car battery ratings, and the higher power replacement battery from Halfords for my Auris quotes 65 amp hours, which at 12.5V would be 812 watt hours, Puts into context how puny those "power packs" are, even if they were at full capacity (which mine was not anyway).
I recall that Francais, who used to contribute regularly to this forum, had a simlar problem with the power socket being switched by the key, when his company car was changed. He used the socket to power his Waeco fridge.
The solution he found involved merely moving the power socket fuse to a different location in the fusebox.
and scroll down to the photos. You will see that fuse positions 1 & 17 are for the cig lighter but only position 17 is populated (blue 15A fuse). Moving this fuse to the alternative position MAY solve your problem.
You can check this beforehand with a multimeter as follows; With key off remove the fuse from position 1 or 17 (there should only be one). Check for battery voltage between a good ground (Car body) and each contact in fuse receptacles 1 & 17, only one contact should be live. If this proves to be the case check continuity between the other contact in that receptacle and the contacts in the other fuse receptacle. There should be continuity to only one. If these conditions are met you have a fuse receptacle with a permanent feed for the cig lighter. Insert the fuse there! Handy hint - When probing auto fuse holders with some multimeter probes it can be difficult to make a good contact. Using a crimp on spade terminal of appropriate size (no need to crimp it) can help.
------------- Never argue with fools........They drag you down to their level, then beat you with experience.
Quote: Originally posted by Ernie DB on 02/7/2023
I recall that Francais, who used to contribute regularly to this forum, had a simlar problem with the power socket being switched by the key, when his company car was changed. He used the socket to power his Waeco fridge.
The solution he found involved merely moving the power socket fuse to a different location in the fusebox.
and scroll down to the photos. You will see that fuse positions 1 & 17 are for the cig lighter but only position 17 is populated (blue 15A fuse). Moving this fuse to the alternative position MAY solve your problem.
You can check this beforehand with a multimeter as follows; With key off remove the fuse from position 1 or 17 (there should only be one). Check for battery voltage between a good ground (Car body) and each contact in fuse receptacles 1 & 17, only one contact should be live. If this proves to be the case check continuity between the other contact in that receptacle and the contacts in the other fuse receptacle. There should be continuity to only one. If these conditions are met you have a fuse receptacle with a permanent feed for the cig lighter. Insert the fuse there! Handy hint - When probing auto fuse holders with some multimeter probes it can be difficult to make a good contact. Using a crimp on spade terminal of appropriate size (no need to crimp it) can help.
Quote: Originally posted by Ernie DB on 02/7/2023
I recall that Francais, who used to contribute regularly to this forum, had a simlar problem with the power socket being switched by the key, when his company car was changed. He used the socket to power his Waeco fridge.
The solution he found involved merely moving the power socket fuse to a different location in the fusebox.
and scroll down to the photos. You will see that fuse positions 1 & 17 are for the cig lighter but only position 17 is populated (blue 15A fuse). Moving this fuse to the alternative position MAY solve your problem.
You can check this beforehand with a multimeter as follows; With key off remove the fuse from position 1 or 17 (there should only be one). Check for battery voltage between a good ground (Car body) and each contact in fuse receptacles 1 & 17, only one contact should be live. If this proves to be the case check continuity between the other contact in that receptacle and the contacts in the other fuse receptacle. There should be continuity to only one. If these conditions are met you have a fuse receptacle with a permanent feed for the cig lighter. Insert the fuse there! Handy hint - When probing auto fuse holders with some multimeter probes it can be difficult to make a good contact. Using a crimp on spade terminal of appropriate size (no need to crimp it) can help.
Unfortunately I checked my Auris's fuse box and all its fuse spaces are occupied.....
So it's back to trying to find a power bank with reasonable capacity and with a 5V USB and a 12V output socket (as well as its jump start croc clips).
A good auto electrician may be able to help you out.
------------- XVI yes?
As well is two words!
How does a sage know everything about everything? or does he? or does he just think he does?
Remember, if you buy something you bought it, not brought it.
Quote: Originally posted by trog100 on 05/7/2023
why not just buy a smallish lead acid battery and cobble up your own connections to it..
trog
A lead acid battery has obvious issues with weight and bulk, to say nothing of the fact it is full of acid ! Also, don't lead acid batteries lose their charge over time and their capacity of left unused for long periods ?
I calculated that using a battery holder for 10 cells and using 1900mAh Eneloop * NiMhs (av voltage about 1.25) would result in a power pack of about 24 watt hours compared to the 19 watt hours of the GE2000 (on test). Using multiple packs in parallel one could quite easily get double that or more.
An additional advantage would be the rechargeable batteries could be used for other stuff when the power pack is not in use.
However......
1 - I have often found those battery holders to be unreliable. It only takes one poorly fitting cell for the output to be, err, zero.....
2 - The above design would quite easily give you an unregulated 12V, but getting a 5V USB output would be rather more problematic. And making it all up in a sturdy case with multiple sockets would be even more so.
* AA NiMhs with greater power are available, up to 2500mAh (which for 10 cells at 1.25V av would give about 32 watt hours) but I have found the 1900mAh Panasonic Eneloops tend to keep their capacity better over the long term.
BLUETTI AC50S Portable Power Station 500Wh Outdoor Solar Generator for Home RV £209 quid
https://www.ebay.co.uk/itm/295762541541?
trog
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Topic: Power banks / jump starters
via mobile 05/7/2023 at 8:00pm
