Battery Chargers/Desulfators/Maximisers

[MULLEY]

I've seen a few of these devices advertised as supposedly keeping a car battery healthy & making it last longer & able to revive old batteries thought too far gone. Has anyone got any experience or knowledge of these types of devices?

Do they actually work & are there any specifc makes & models that are recommended? I've pasted some links to some stuff i've found.

http://www.sulfarid.com.my/sulfarid.htm


http://cgi.ebay.co.uk/Battery-Desulfato ... tDomain_15

http://cgi.ebay.co.uk/OXFORD-360T-MAXIM ... ycle_Parts

http://cgi.ebay.co.uk/BRAND-NEW-CTEK-MU ... very_Tools

[electrokid]

Hmmm - cost half the price of a new battery - and adds 50% to the life of the battery - so that's equal cost until you use it again on the next battery!

Crystals drop off the plates anyway during normal use - they accumulate at the bottom of the battery and if the plates went all the way to the bottom of the battery they would short out the plates and the battery would be duff in a matter of weeks. So the plates don't go all the way to the bottom - decent batteries will have enough space here for crystals to accumulate without shorting out the plates for the warranty period + and since more crystals drop off during the 100s of amps starting load it's here that the bigger-than-standard batteries that you and I favour work well - because they are designed for a higher start current there's less 'damage' ie: fewer crystals drop off at each start. I've had a 3 year warranty 'big' battery last 5 years even with abuse.

So... do the widgets work ? Well yes they do - as long as the problem is just lead sulphate crystals and there's enough space at the bottom of the battery to allow them to gather without shorting out the plates. If the problem is that the build up of muck at the bottom of the battery is already causing battery drain then they might blast that out of the way for a short while but the battery is soon to die anyway - they impose high voltage spikes onto your charge current.

Just a personal opinion - I'd put them in the 'get you out of a jam' category rather than something I'd use on a regular basis - you may find other folks who swear by them.

[MULLEY]

Cheers for your thoughts electrokid, i was just wondering what peoples views & experiences were of using them or not? Is it snake oil

[Gibbo2286]

When my engine blew up I got a can of 'Holt's liquid engine', poured it under the bonnet and drove away again. Gibbo.

[scarecrow]

I'd guess all of these things have some basis in science, but in reality are just a way to squeeze your nuts a little tighter.

Manufacturers would add them to their products if they were worthwhile, in my opinion.

I was looking at some magnets the other day that were claimed to polarize fuel molecules stopping them clump together... Before that there was a device which was supposedly a bolt-on direct injection hydrogen fuel cell...

The lure of a buck, eh? And the lure to save one.

[electrokid]

There are a few things know to work to an extent - swirl devices which spin the airflow just as it enters the inlet ports - and multi-spark ignition systems - both increase the chances of more of the mixture burning more smoothly.

[mat_fenwick]

What about swirl devices that fit onto your exhaust tailpipe and help extract the combustion gases by spinning in the airflow?

[electrokid]

Is it snake oil

No - but if your battery is on the way out and you use one of these it will work for a while - but you still have a battery that's on the way out. It just seems to me to be better to get a new battery so it's not a worry for another few years ?

swirl devices that fit onto your exhaust tailpipe

About as effective as the fairy lights on BMWs I'm glad I spotted the - I was about to prattle on about exhaust tuning

[KevR]

I've got several 'smart' battery chargers that I've acquired over the years, some as products to test for motorbike mags, some I've actually spent my own money (although not much of it) on.
Biggest advantage of them is if you've got a relatively low capacity battery and/or a big starting current drain, which is the case on most motorbikes, especially big twins (got several of those) bikes fitted with an alarm (don't have any of those, hate the things) and/or bikes/cars that aren't used frequently so are in danger of the battery flattening itself over time (got lots of these). Because you can leave them connected, you can be pretty sure that when you come to start it, it'll have the juice to do it. For a car used every day, if the battery needs to be on charge all the time then it's time to change the battery.
FWIW I've had very good results with the original Optimate, the Acumen version, and the Battery Tender Junior (waterproof so handy for the tractors etc). All those are pretty expensive. At the other end of the scale I've also got two simpe smart chargers from Lidl (one of the weeks they were selling motorcycle stuff) and they were only 7.99 euros each. They work a treat, turning themselves off as soon as the battery reaches a certain voltage, turning themselves back on when it drops.

As for 'saving' knackered batteries, in my experience if a battery's just starting to get a bit marginal (for example where it's been damaged by letting it discharge too deeply, too often) a smart charger can sometimes bring it back from the brink, but they won't rescue a battery that's simply got to the end of its useful life anyway.

[Mothman]

I use a 'smart' charger to recharge a 120 amp hour leisure batt i use to run a moth trap and ive been using it and the batt for 3 years now and batt is still ok for 10 nights running. However on full charge the batt runs down in 3 nights when i first start to use it in the spring but after about 3 charges it perks up and then starts to last much longer. Its in full nightly use from March until December. The charger seems to give the batt 'new' life.

Andy