Which smart charger for AGM batteries?

[michaellxv]

So I recently purchased one of the ALDI 38AH AGM batteries discussed here
http://www.iceinspace.com.au/forum/showthread.php?t=170312 and this raised the question of which charger I should get to go with this battery.


I have an old car battery charger that puts out continuous 12V DC 2.68A which would charge it but it's dumb and wont stop charging when the battery is full.


A smart charger has been recommended but which one? They seem to come in anything from 3 stage to 9 stage and anything up to 15A :eyepop:. A charge rate of 1/10th C has been recommended which would mean 3.8A max for this battery.


I also have a jump start with a 17AH battery and a compressor/inflator with a 7AH battery that would benefit from some smart charging.


I have looked through the Jaycar and SCA offerings, found a few other online vendors and of course eBay and there is a wide range to choose from starting from $20 up to well more than I want to spend.


Do I really need any more than 3 stage?
The smaller chargers cover the range 6-20AH, but would they work on a larger capacity battery but just take longer?
The larger chargers start at 20AH and go up from there, quite often with a min charge rate of 2A which is too much for my smaller batteries.


:help:any recommendations on a good value smart charger?


Michael.

[Lee]

I use a 10A version of one of these by Projecta.
https://www.projecta.com.au/battery-charger-products/12v-automatic-7a-7-stage-battery-charger
Seems well built, offers selectable charging current and battery chemistry. No problems at all...

[DeWynter]

I’d say you need a charger with more capacity than the battery - it will charge faster and better. A smaller ones will work but charge longer. Think about it like it’s a tripod for a scope. Can you put a large and heavy scope on a smal tripod? Of course you can. Will it work? Yes. Will it work good? Not so. Same here. Of course you don’t need 25A charger - it’s an overkill. But it should be slightly above for what you need.

More than 3 stages... probably not. Good to have but in reality you need it only if you are charging battery all the time and it’s in heavy use.

I’d recommend CTEK chargers. They’re expensive, but very good quality. Last forever. Top ones will definitely be out of the range you want to pay, but check the one that suits your power. Also eBay is a good source for CTEK’s that less expensive than at SCA.

[DeWynter]

Check this one: CTEK MXS 3.8 (https://www.ctek.com/au/products/vehicle/mxs-3-8) for batteries up to 85Ah or this one CTEK MXS 5.0 (https://www.ctek.com/au/products/vehicle/mxs-5-0) for batteries up to 160Ah. CTEK MXS 3.8 costs $100 on eBay.

[acropolite]

Probably well out of your range but Victron make some amazing chargers, some models have Blutooth so you can modify charge and monitor the State of charge from your smartphone and will also charge Lithium batteries. Victron Bluesmart chargers start at around $170

[Marke]

I have a couple of Ctek I would highly recommend them . One in my Obs has run 24/7 for 6 yrs now

[Madanie7]

I am in exactly the same position as you, Michael, with the same Aldi battery.

These got recommended to me, Haven't bought it yet.
https://www.projecta.com.au/battery-chargers/
The pro range.

$97 at Bunnings
https://www.bunnings.com.au/projecta-12v-battery-charger-pro-projecta-12v-1-4a-pc400_p4420250

What battery box did you get for it? I am about to buy one.

[Steffen]

I second the C-Tek recommendation. Mine (MXS-5.0) has been in use for years without ever missing a beat.

[michaellxv]

Thanks for the suggestions, looks like I have some homework to do.



Nothing yet. I looked at a couple but they are designed for larger batteries. I might just use the box it came in until that falls apart :rofl: Besides I want to see how I really use it so I can work out what a box might need apart from 6 sides.

Michael

[Madanie7]

I bought one from Jaycar today. A bit big but I will chock out the base so the battery is snug.
I also bout the power tech plus 4 stage charger from there as well.
Seems to all be going ok so far.

[that_guy]

You dont need a baterrybox for these as theyre nicely sealed. Just grab a few anderson plug connectors with 12v sockets and grab a cheap multimeter to check voltage every now and than.