advice needed for right selection of 12v solar panel float charger for agm battery

[steptoe1111]

hey guys how is every one
i was just after a little bit of advice on a 12v solar panel to maintain charge
(float charge)for a AGM 12v while its being stored in between trips and of course through winter......its my first battery, i endid up going with a AGM 100ah 12v battery because i read alot of good things about them
its just for trolling with a 40 lb motor on 12ft tinny
but like i said above id like a solar pannel just for maintanence and long life in between storage iv been looking around and i have seen some 5 watts and some 1.5 watts .... are these suitable and recomendid for agm"s eventhough they boast a remarkabley low self discarge... if so what size would match a 100amp/h 12v agm? just to do whats mentioned above
thankyou very much and safe boating to all

 

[Silvertip]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

A 1.5 watt panel is absolutely worthless. 5 Watts is a far better selection. They are available all over for about $20 - $30 depending on where you shop. By the way -- where is this battery going to be during storage? If its at your house, buy a plug in unit. If the panel will be in a storage lot or even outside your house it is a target for thieves who not only get your panel but the battery too.

 

[steptoe1111]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

ha ha ha the pannel will be out side..... battery will be inside ,it ways a tone
30kg and cant see anyone running to fast with that .... as for the theives
well i put my own alarm and cctv in " dont know where id be without em"
but i apreciate your input.... ill go 5 watt then ive been looking on ebay and yeh the price is ok too
ive also been reading about chargers, do i need a smart charger or suitable agm or deep cell charger ???? all i have is a 4amp car (wet cell) charger from what ive read these dont do agm batterys much justice

 

[Silvertip]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

Smart chargers are a must with any modern battery and it must have a "charge profile" that suits your battery. Since the battery is inside, why not buy a simple "battery tender" (typically a small, 1.5 amp) plug in unit that can be plugged in and left connected indefinitely. I use a solar panel in my shed to keep my tractor battery topped off during winter storage but there is no power out there so that's a good alternative. But I also have a cargo trailer set up to haul my r/c airplanes and it has 12 volt power as well as 110 AC wiring in it. I use a Schumaker 1.5A smart charger to keep that battery topped off as the trailer is in the third stall of my garage. It is plugged in 24x7 except when on the road. I do have a timer on the charger during the winter since the rig doesn't get used much except for when I have lights on and am cycling airplane batteries. My boats have always used one of those on the starting battery as well since those never get deeply discharged.

 

[steptoe1111]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

hey thanks heaps for that Silvertip
that battery tender sounds like a better solution .. i know the ones you mean probly half the price of the solar pannel too, i have a coulple of small plug pack chargers already that did belong to some old scooter batterys and kids
4wd , but from memory they supplyed a 15v max charging current "well the plug pack was rated at 15vdc i stil use them on smaller batterys like seald lead acid 12v 7amp/h, and i found that it actualy gave them a much better charge than the chepo arlec 4amp car charger wich i found left them fairly sulphated afterwards, wich is the main thing im desperatly trying to avoid with this one ... i have a clip on desulphater from jaycar but hope i never have to use it on this beast of a battery

i read that agm batterys dont like being charged over 12.6 volts
and dont like when you discarge them more than below 40% wich is ruffly
12v-12.2v so is this the parameter i have to work with when selecting a suitable charger should it not put out more than 12.6v ? or bluntly is that why there called "smart" charges cause they work all this out for you
thxs again mate i realy apricate your precious time and input thxs

 

[Silvertip]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

12.6 volts is the normal static voltage for a 12 volt battery -- any 12 volt battery. "Charge Profile" means a battery has a specific charging process or sequence that the battery should have in order to provide optimum life. That charge profile is built into the charger. The charger may have a switch or plug that you set for the battery type being charged. The term "smart charger" means that the charger follows the selected "charge profile" and turns itself on and off as required to prevent over charging and to prevent the battery from "self discharging" over time. Hence it can be left connected indefinitely. You have an AGM battery. You need a charger/maintainer that has profile selections for an AGM battery. The instructions or descriptions for the charger will tell you what the charger is capable of. Unless your battery tenders say specifically "not for AGM batteries" they should not damage the battery. Check the instructions or do a Google search for instructions for the make and model of your charger.

 

[steptoe1111]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

thanks for that again silvertip
but just one more question would a add on regulator kit for the arlec 4amp charger be suitable from what you have told me about smart chargers turning them selves off to prevent overcharging well aparently this kit does just that
you can view it here
http://www.littlebirdelectronics.com/products/Add%2dOn-Regulator-Kit-For-12V-Battery-Chargers-.html

 

[Silvertip]

Re: advice needed for right selection of 12v solar panel float charger for agm batter

This would certainly be better than a very un-regulated charger. However, the Schumaker 1.5 amp maintainer for example sells for the same price (depending on where you buy). I've used a bunch of those and they work very well. Whether you add a regulator or buy a different charger, remember that it must have a profile for your AGM battery.