Floating vs Storage Voltage Question

wa8yxm wrote:

time2roll wrote:
13.2 works well when combined with the 15 minute boost charge at 14.6v every 20 hours.
Otherwise storage and float are the same thing as far as I am concerned.

My original house batteries lasted 9 years with a PD-9180+wizard doing the above pattern

X2!

9 yrs and could have gone a couple of more but wanted to make sure my home fridge wasn't going to run me out of battery.. And I am using a PD9160 with external Charge Wizard.

13.2V is what I have found maximizes battery life when not being used (AKA "Storage") combined with the PDs Charge wizard giving a short 14.6V bump every 20 hrs during storage.

13.8V in storage is way too much no matter what the temperature is, it WILL boil the battery to death if allowed for too long of time.

13.8V is the target charging voltage of a older automobile alternator/charging system from the 1980s and older.

Old linear converters had a fixed 13.6V and they boiled batteries to death. My first TT had a linear converter and it ate batteries for breakfast, lunch and diner, boiled quite a few batteries before I realized that I HAD to disconnect batteries while being stored, otherwise suffer the cost of another replacement.

And, I will say this, a few of the portable devices I have built for myself which use Gel and AGMs, well I set my charger voltage to 13.2V and they reward me with very long life.. One device with a gel battery is going on 15 yrs, still works although doesn't have the capacity it had new.

If you REALLY want to charge harder, then go with a fixed 13.8V supply and put it on a 24hr timer, give it 4-6 hrs of charge per day for storage.. That is what my local Ham club did for yrs for their backup emergency batteries.. Worked pretty well but with the advent of multistage charging it isn't worth the hassle to me.

Seems that a lot of folks here fuss and obsess way to much on batteries, folks like PD have figured out on how to build a converter which can maximize the life of your batteries without much intervention or fuss of the user.

Sure there are more "advanced" converters with temp comp and even different charge curves for different types of batteries but in reality that extra fuss might net you one more month of life, not years like folks think it will.

Ask Mex, I know he has built all kinds of charging schemes with all kinds of required human intervention.. Might give you a bit longer battery life, but at the cost of your own personal time which you can never get back.

Batteries you can replace, your own personal time you never can replace..

Best advice I can give is, batteries are a "consumable", each time you cycle it, you consume part of its life.

That harder you consume it, the faster you shorten it's life.

Shallow discharge followed by a quick recharge will net you with the longest life.

Over or under charge, will destroy a battery just as fast a deep discharge or allowing to sit partially discharged.