top off AGM deep cycle from auto alternator

[zingarofunkart]

Hello:
Im trying to use a deep cycle agm batt  and recharging it from an auto alternator which from this site ive learned it will NOT be fully charged..

SO: i want to try and top it off using a small 7 wt solar panel mounted on the roof.
Will i need a charge controller ? and it looks like ill need around 10 12 feet of wire to get to the battery. Suggestion on size wire.

And is it ok to hook up a panel straight to the battery that is getting its primary recharge from an  auto alternator ??
thx ...z

[bob g]

i don't know where you got the idea that  you cannot properly recharge
an agm battery with an automotive alternator?

you can recharge an agm, a flooded, a gell cell or just about any other battery with an automotive alternator, of any common voltage used in RE/AE installation, provided you use a controller in lieu of the oem regulator.

companies such as balmar, xantrex, amplepower, hehr, heart interface, leece neville (a balmar product), strerling, among a few others have either built or have in current production high performance multistage controllers that are programmable to do 3 stage charging and many also have switchable equalization, temperature compensation, alternator temp sensors, amp manager functions to tailor the available hp to match it to the alternator, remote sense, among many other capabilities.

yes some can be quite expensive, but many of the lessor known units come up on ebay for very good prices, and sterling has a couple of units in the sub 100 dollar price range available from sellers on ebay that are brand new, never been used.

an engine driven alternator is a reality for folks using a battery bank, and as such the use of one of these controllers not only will work, but will charge a bank more efficiently than any other system available that used an engine to drive it.

one of the most effective and efficient battery charging alternators available is the 110-555jho prestolite/leece neville, i have written extensively on its use with a controller. there is no more efficient battery charging scheme available today than the coupling of this alternator with a 3 stage controller such as any of the above mentioned units, when used with a 24volt bank and very hard to beat used on its native 12volt nominal voltage battery bank..

there is nothing wrong with topping off with solar, however a 7watt pane is not going to top off a very large battery bank in my opinion.

if you already have an engine driven alternator, i would strongly suggest the use of a sterling controller, for the price they are very good
and will do everything you want or rather need done.

bob g

[zingarofunkart]

Thx. Bob
the blurb about fully charge was in reference to a deep cycle. Ive used them in the past for a starting batt + rv service and they didnt last long (interstate wet cell).

My application will have two batt a wet cell starting batt and one agm isolated from the starting batt but charged from the same altenator.

I was hoping to use the 7 wt solar w/o a controler to top off the agm.

I was planning on using the optima 100 ah but havnt located on local yet.

Again. thx for the input ...z