Model Boat Mayhem
Technical, Techniques, Hints, and Tips => The "Black Arts!" ( Electrics & Electronics ) => Topic started by: meechingman on February 23, 2016, 02:20:57 pm
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I have a collection of 6V L/A batteries for my fleet, most use 6V 4AH, but the biggie uses a 6V 10AH lump.
Problem is I can't locate my 'carefully put away' charger. 6V @ 500ma. It's around somewhere I'm sure but being sure won't charge the batteries. I can just buy another one, they're not expensive but before I do I thought I'd ask this....
I have a Ripmax ProPeak charger for charging the batteries in one of the fleet and for an R/C car. It's 7.2V to 8.4V, variable current from 0.5 right up to 5.5A. Can I use this with lead acid batteries and, if so, what sort of current would be safe to use?
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I don't think so.
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NiMH, LiPo and NiCd batteries require a constant current charge whereas lead-acid require a constant voltage, so E2V is right - the answer is no. Before you replace the mislaid one, have a look around at what's available. You can now buy chargers which will do both SLA and NiMH/LiPo packs, either from a mains supply or a 12v battery (or sometimes both).
DM
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Thanks for the advice guys. I had a feeling that would be the case, so I'll take your advice and look around to get a replacement - when it arrives, I'll no doubt find the original!
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Thanks for the advice guys. I had a feeling that would be the case, so I'll take your advice and look around to get a replacement - when it arrives, I'll no doubt find the original!
my bet is within a week!
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It turned up yesterday, the day after I ordered it! Alas, my set of SLAs have been sitting on the table doing nothing for over two years (health issues prevented any sailing :(( ) and seem to be dead. The charger's LED stays lit up, and according to the instruction manual (well, instruction slip!) that comes on if 1) there's no battery connected or 2) it's fully charged. After 9 hours 'charging' the 6V 4AH battery read just over 3V.
Can these dead'uns be brought back to life? Again, I don't mind spending out for a new set, as I'm going to get some lake time in this year, but I hate the idea of just recyling them if they could still have some useful life in them.
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If you search the internet you will find people who have bought lead acid batteries back to life, In my experience though it isn't worth the bother trying, (and I have tried), even if you do get some usable life back they are never the same again.
They build up sulpher crystals inside them, the idea is to break these crystals down, I built a pulsar circuit a few years ago, you can find various articles, theorys and circuits around the internet but I never got any real success with mine.
You can move over to other battery technologies which have their pluses and minuses but if you do that you will need to put a load of lead in your boats to re ballast them.
Batteries eh?
I'm going now to check a couple of mine I haven't checked for a while.
Neil
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Dead SLA batteries make useful ballast, and you might just get a refund for the charger against some new NiMH or LiPo packs if you ask politely.... ;)
DM
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Dead SLA batteries make useful ballast
What a good idea.
That just gave me a 'why didn't I think of that' moment. :)
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Why use a dead SLA battery for ballast then another battery for power.
If the model has been working fine previously why change.
I have a large tug and a 12volt 20Ah battery ballasts her and powers her fine.
I just dont see the point of changing to MiNim or Lipo and needing a LOT of ballast.
Bob
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I have recovered 'dead' SLA's by connecting them up to a small solar panel, and just leaving them with the panel in the sun for a few months, the panel I have is about 6" x 12" and only very low output, sometimes the daily small charge can get a battery back on its feet, sometimes not.