So let me try to sumarize a list of suggested changes that i got from this thread
- Replace 8G wire with 4G (+ run from main battery to trunk) to minimize voltage drop
- Get a bigger battery i.e. the Yuasa NP (currently i have a 17AH. perhaps 38AH. )Bigger batteries can charge faster
- Get a battery that is fit for cycles instead of standby use.
- Install a solar charger
Did i miss anything?
BTW to answer your question MickZ... there are several short trips during the day
I'm generally not in favor of solar chargers for their expense and they need a regulator (despite what people say), and as Mickz said, the sun can be unreliable (and the panel must face the sun etc).
In this case though it might help. (Depends on discharge-recharge cycle.)
You really need to look at battery specs and compare to your system to determine a size, but it might be reasonable to assume almost double the charge rate for a doubling in size.
But I think a cranking battery is the better choice - provided it is not discharged past 80% (20% DOD) - it should charge faster than a deep-cycle, else at least tolerate the short-fast charge better.
The Yuasa NP was merely an example, and an economical one for 7AH.
But 15AH generally is considerably more - eg 3x the price for only twice the capacity. Maybe 38AH or larger is more economical wrt AH per $ and - providing it is reasonable charged - should [I]live/I] longer - ie, its DOD won't be as big, and it should recover that lost charge quicker (the bigger, the better as they say...).
Alas there are still so many variables...
Here is the battery that i have easy access too. I actually have 8 of these.
If i parralled 4 of these how long could i expect to run them... (a year?)
Originally Posted by OldSpark
Since AGMs usually require 12-monthly top ups, probably not - unless you are charging them as you said.
As to their behavior I have no idea.
Firstly you haven't even provided a load, let alone the charge profile.
Secondly you are paralleling them. If one dies, they all die (given enough time).
They seem like 7AH batteries but for UPS (hence the low discharge times up to 90 minutes). They'd be built for high discharge currents.
I'd recommend a single larger battery (38AH or larger based on your existing being ~15AH) with a longer discharge time.