Battery charging.

[Paul75Participant @paul75]

Hello Everyone.

Sorry in advance for this very simple question – I really am very new to all this!

I've just received a 6 volt 14 Ah sealed lead acid battery and a 6 volt 1500mA charger. Needless to say the instructions supplied are minimal to say the least.

How long would you suggest I leave the battery charging for its first charge?

Many thanks,

Paul.

[Paul75Participant @paul75]

[ashley needhamParticipant @ashleyneedham69188]

Paul. I have not had such a large gel battery, but the charge rate of your charger sounds a bit excessive to me. My understanding of these things is a more like 500mA (0.5A) would be better.

The automatic gel chargers seem to cut off too early for my liking, and my non-automatic charger i leave on until I can hear the battery JUST start to vent (bubble). Likely your battery will be fairly well charged from new and it wont need too much of a charge.

This is unlike a niMh battery which would need a long slow trickle charge first, and a few discharge/recharge cycles before it attains its full capacity.

Ashley

[Malcolm FraryParticipant @malcolmfrary95515]

SLA are OK charging at the 10 hour rate, for a 14AH battery, just about 1400mA. If your charger can give a max of 1500, you are not going to get much nearer than that. If it shuts off automatically, trust it. If not, then 12 hours max for a well discharged battery. That is more than 10 hours, but the chemical conversion is less than 100% efficient, and as the battery voltage approaches the output voltage of the charger, the current naturally reduces, quite apart from any control that the charger might introduce. If it isn't fully discharged, and the charger carries on at full rate, damage will happen. Fortunately most chargers, especially ones sold in the model trade, are limited to a voltage where this will not be a problem. They are intended for use by people who do not have an electrical background.

Ashley, if you hear the battery vent at all, you are shortening its life. If it vents, it is losing electrolyte that you cannot replace. Sealed means that nothing gets in, and it is sealed for life. When it gets empty, its dead. Trust the automatic cutout, it does know better.

If the charger can be set for a low rate, and 200mA would be low for that size of battery, it could safely be left indefinately, but would need at least 3 days to fully charge from flat.

[ashley needhamParticipant @ashleyneedham69188]

Malcolm. Notes taken! Ashley

[Paul TParticipant @pault84577]

I would be the first to admit that my knowledge of electronics, batteries and charging is limited to plug & play and that anything more than this falls into the realm of black arts which I am very happy to leave to the Grand Wizards of the dark side such as Lord VolderMilbourn (don't speak his name out loud)

But I do worry about leaving batteries on charge waiting for the auto cut out to work especially when the little buggers start to get get hotter and hotter.

Give me good old petrol engines any day……this is technology that I do understand.

Paul

[Paul75Participant @paul75]

Thanks for your replies.

The supplier company stated that the battery and charger are compatible. I've just had it on charge overnight (approx 12 hours) and it seems to have charged up nicely.

Now to assess the duration of charge of the old Digifleet XP/FM system Tx/Rx rechargeable batteries! The instructions say full charge should amount to 2.5 – 3 hours usage based on 5 channels hooked up. Hopefully the 20 year old kit can still achieve this!

Thanks again,

Paul.

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