Alternator booster fuses

[Malicious]

Ok so this is a bit of a rant.
Reading fakebook today and 4wdTV had a guy selling his version of one of these devices so what is inside for $98 not much, it will increase output voltage by 0.4 to 0.5 volt , on eBay fusible ones sell for about $25 ones that have auto resetting fuses are about $50.
There is no way that these are a replacement for a DC to DC charger .
However if you are on a tight budget they will help .
So I have decided to make my own version of these items why cause like the temp sender I dislike seeing people being ripped of and crapped to.
Once things get back on track and I do the diff breather kits these will be my next thing.
Pricing will be about $25 each they will be auto resetting and any I sell to forum members will have a percentage of the price donated back to the forum.
So my rant for today is if you pay $98 for one you are part of the way to a DC to DC charger and just got ripped

 

[TigerST]

Yeah I was thinking that my self......

What I do find interesting tho is how come people put in smart alt with a battery that needs a higher rate of charge. Never heard of it till the guy from redarc talked about it.

 

[Malicious]

The D40 has a hall device that feeds back the current draw on the negative side so putting in a battery which does use a bit more current doesn't matter so much. One of the biggest issues is using different chemistry batteries for their different advantages, this is where a DC to DC comes into it's own

 

[TigerST]

Thanks.

Well once mine dies I'm swapping it out with a yellow top.

 

[Old.Tony]

Mal to the bloody rescue again!

My next battery will be a LiFePO4. 100Ah battery that weighs just over 13Kg? That's for me! Normally I don't care if something's a little heavy - those that have met me will know I'm not a small guy, and holding up a 38Kg winch with one hand while I put the bolts in with the other is no drama, but this sort of weight reduction is a different thing.

It means that in place of the 27Kg Optima D31A that I have now (75Ah) I can put TWO of these LiFePO4 batteries - 200Ah - almost tripling my power storage in the same amount of weight.

I get the choice of being able to stay off-grid for longer, or simply reducing my weight to carry other stuff (like water) when I'm way out there.

There's a catch. Here's a sample on eBay. The listing won't stay there forever, so when it's gone here's the details: 100Ah LiFePO4 battery, 13.5Kg, $1,320 buy-it-now. Whoa!

Prices will HAVE to come down to make that more affordable. Longer term it's worth it, because this thing can be cycled 2000-3000 times compared to the 500-odd of my D31A - so that's 6 times the life expectancy, which means I'd be on my 6th D31A at $350 each ... if you have the coin, the LiFePO4 is definitely worth it.

But, back on track, I have a question (for you, Mal) about these "fuses" - are they designed to just fool the alternator? Is this a switch in the green wire in disguise? If they're flogging that for $98 then they should be ashamed of themselves.

 

[Malicious]

All these fuses are is a fusible link or ptc fuse and a bipolar diode , that just fool the alternator , hence why only a 0.5v increase as that is the drop across the PN junction of a silicon diode that's why $98 is a rort and I'm over it.
So it will give a increase in voltage but not full output like the green wire trick,
Hence why they are not a replacement for a DC to DC charger , they have their place for those who run same chemistry batteries but a waste of time if you run different batteries , the ad that 4wdTV links to the guy needs to go back to school.
I'm actually thinking of writing them a email to ask how his product can actually do what they claim. Back to your post Tony LiPO batteries are the way things are going and price has been dropping , I was playing with some packs a few years ago and they were $1200 same pack now is about $200,

 

[sparra04]

but lipo's aren't cheap and they tend to do this, luckily I caught this one in time
I wouldn't want that happening in my van when I am asleep, or cruising down the hwy

 

[TigerST]

The VE comes out with LiFePO4 standard if I remember correctly. My mate has one in his love it in away. Runs all his ICE, but as he said can't jump off it or let it go flat.

 

[Old.Tony]

LiPO (Lithium Polymer) is a different technology to LiFePO4 (Lithium Iron Phosphate). Massive increase in energy density and recovery, unlike the LiPo batteries we're getting in RC gear. I hate the LiPo crap, they're bloody expensive and they just don't last at all. Not that LiFePO4 is any cheaper - it's not - but at least it's fundamentally stable. No acid in them either - so dangerous spills are a thing of the past too.

The sales pitch for LiFePO4 is that you CAN let it go flat, unlike lead acid (which causes sulphation and eventual shorting of the cells). Whether that's true in the real world or not I can't say, I've not tried one and haven't read anything reliable on these (eg from Collyn Rivers, who I might just email about it and see what he says).

 

[TigerST]

For what my mate was saying if he lets his drain flat it will take appox 10 hours of running time to recharge it. If this is correct or not is a different matter.

 

[Old.Tony]

Oh they've got a lot of energy density, that's for certain, and the alternator can only put in so much. My Commodore had a 120A alternator but again that would only deliver 120A when I was wringing the life out of the engine.

If you had a 100Ah cranker (lead acid) and flattened it, and had a charge rate of (say) 50A (average driving current) minus 30A (to run things) = 20A available to charge = 5 hours to recharge the battery. It would actually take longer, because the alternator is only charging at 14.1V (fast charging requires nearer to 15V).

So yeah, he'd be right, but he's got more capacity to recharge too (for the weight).

The Wiki page is an interesting read.

 

[TigerST]

So basicly seen it got so much capacity its less likely to drain flat...... Still 10hours is a long time.