best Solar battery

[hartiberlin]

I just found this Gel battery on Ebay and wanted to ask,
if anybody has some experience with this,
as I need to buy a battery like this for some experiments.
It has 12 Volts and 65 Ah and costs 75 Euros plus shipping..

http://cgi1.ebay.de/ws/eBayISAPI.dll?MakeTrack&item=6063041490

[hartiberlin]

Is it better to get such a gel battery type like shown above  or
is it better to get a normal solar battery type with
refill-opening for the battery acid
like this item on EBay:

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=6063299260

This one says, you need to refill destilled water from time to time and also
pay attention on the oxyhydrogen gas during charging, that must be ventilated,
so it seems it is much more dangerous, but you can completely refill the acid if you need
to do this ...hmmm....
What are your experiences ? What are the advantages and disadvantages ?
Many thanks.

[hartiberlin]

Do these gel batteries not gas out during charging ?
What if they loose the acid due to drying out ?
So what is the better battery type for deep discharge
experiments ?
I know, that I don?t have to buy car starter batteries, but what is
the best battery that will last best for deep discharge experiments
and pulse charging  ?

[tbird]

hi stefan,

i have lived on a boat for the past 25 years.  for us boaters with solar and wind charging, the 6 volt golf cart batteries seem to be the best bang for your buck.  if you have a sam's or similar store, they will give you the best retail price.

gel battieries are very good, but have 1 weakness.  overcharging.  they usually cost too much money to be killed by too much charging.

glassmat batteries handle that better and are sealed (no gasing out), but are still a bit pricie.  haven't seen enough of them in use yet to grade them.  maybe they will take over best buy.

the gasing of a battery (comes when battery has had enough amps from charging to get too hot) is natural but messy and if contained explosive (hyd & ox).  regulation is important if they are left to their own.  in my case, with all my uses, it's hard to overcharge (no reg here), but it does happen.  the end result is i have to add some rain wter or water i've caught running off the air conditioner (on shore business or friend).

if you can spread the cost over time because you are seriously using the battery, then the glassmat might be the thing to look for.  if 4 years is enough (and with battery tech advancing now, smallest investment might be best) then regular lead acid golf carts would be my choice.

1 tip for lead acid...the heavier the better.  that's why i go for the golf cart (6 volt) batteries.  i know i'm getting deep cycle (hard to tell with 12 volt batteries except for weight).

[hartiberlin]

Hi TBird,
many thanks for your experience.
Do you draw a high current always from your batteries ?
What do you power with it ?
Do you use an inverter to push upthe voltage to 120 or 230 Volts AC ?
Normally, the lower the current is you draw, the longer do the batteries
last.
As I need them to drive an inverter with it to get 230 Volts AC I am
thinking of getting 2 x 12 Volts batteries and better buy a 24 Volts DC to 230 AC Volts inverter,
which is of course more expensive but the current draw from the batteries will
be lower, so the charge would also last longer as batteries tend to deliver more energy
when the current in Amperes is lower over time...

Also I need to recharge them during the inverter is running with a feedback loop
and because it is all pulsed, I have fear of overcharging them and then they might
explode and I don?t want to have the acid spread and spilled all over the place then..

So which batteries are better for not gasing and building explosive gases during overcharging ?