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ozscott
05-02-2015, 07:43 AM
Hi good people,

I have a 35 Amp hour (D3-35 Full River) AGM in my yak for my 18p Water Snake leccy motor. Its 11kg so its a good size.

I bought a CTEK charger before I bought the battery - MXS 5.0 Test and Charge. That charger says it will do just under 1.2 AH to 110 AH and (up to 160AH for battery maintenance). It says it suits AGM - ie all lead acid batteries. I thought it would even charge up my Coleman hot water system batteries etc. I also have a 115AH Full River Dc Series batt for camping so it should do that nicely too, albeit that batt is at the top end of what it can do.

I think it will work fine, but even on the little 35 AH AGM it says on the battery label that the best charging amperage is 7 amp - but the little CTEK is only 5 amp...

As I understand it AGM's need to be charged to a higher voltate - about 14.7v compared to stock lead acid batteries, so surely 5 amps will get the little battery to that level, but it might take a bit longer than a 7 amp...

Another question, I have 160w solar panels with a cheap chinese regulator that is not particularly for AGM - just a cheap reg. If I take the panels camping and use them to charge the little battery for a weekend I dont think it will hurt the battery as long as I sit it on the AGM charger when I get back...anyone know?

Anyone got any ideas?

Many thanks

kind_cir
05-02-2015, 07:55 AM
Got the same ctek 5.0 charger and I use it on everything with no dramas. 4wd and car wet cell, 100ah agm in van, 24ah wet cell in ride on mower, and 12ah agm in tinnie

Chimo
05-02-2015, 07:57 AM
Perhaps consider asking techstore@jarcar.com.au.

I just got a flyer in the paper from them; hence the email address; and they have a range of what look like CTEK chargers on sale ie models MB-3603 up to MB3608 (9 stage 12 v 24 v 25 A) $50 off for $349) Might check them out myself later today.

C
C

scottar
05-02-2015, 09:07 AM
That 7 amps is a maximum initial charge current to limit heat generation. It will be fine. I use a smaller Jaycar version (4 Amp) to charge a 75 amp AGM for the tinnie. It just takes a bit longer. The solar system at 160 watts is a bit over the recommended max of 7 amps in full sun but provided the battery is not overly discharged and then hooked up at a peak solar production time I would think it will be ok. You could always put a meter in series with the solar to keep an eye on the charge rate if you think it is getting too hot.

ozscott
05-02-2015, 07:07 PM
Thanks Gents. Scottar I could always cover a panel or part of a panel to get the amperage down I suppose?

Cheers

scottar
05-02-2015, 07:24 PM
Yup, that would work.

Marchy001
06-02-2015, 09:29 PM
Does it say the same charge rate on the larger battery as the small one? Generally a bigger AGM battery can handle a little more current.

Also when camping the battery will probably be cycling a fridge I'm assuming as well as other items possibly while it's charging so it won't be getting the full input from the panel at all times. I would just take as much power from the panel as you can to keep your battery at higher state of charge.

Probably be less damaging exceeding the charge rate by x% from time to time than running your battery down more over your trip.

ozscott
09-02-2015, 10:31 AM
Thanks Marchy. So the big one has a much higher recommended charging amperage. Both batteries have both a recommended charging amperage and a max charging amperage. I used the Ctek 5.0 to charge the little one and will charge the big one today.

Cheers

TheRealAndy
09-02-2015, 05:38 PM
Use the motorcycle setting on the CTEK (if yours has it).

I have a similar size small AGM for my sailing boat for VHF and nav lights and I just charge it up using the CTEK MXS5.0 on motorcycle agm mode. Been doing it this way for years and battery is still going great.

ozscott
09-02-2015, 06:45 PM
Thanks mate. According to the owners manual that setting is for batteries up to 15ah and mine is 35ah. Cheers

TheRealAndy
09-02-2015, 08:54 PM
Thanks mate. According to the owners manual that setting is for batteries up to 15ah and mine is 35ah. Cheers

The motorcycle mode just limits the charge current. It wont hurt your battery, it just means it will take a little longer to charge.

Source: I used to design battery chargers for commercial use!

ozscott
09-02-2015, 09:31 PM
Cheers mate

Fed
10-02-2015, 07:12 AM
What's the voltage output on the chinese regulator ozscott?

ozscott
11-02-2015, 08:39 PM
Not sure Fed. Not stated on Reg. Cheers mate


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