Auto Battery and Charge Controller

boisblancboy

I just recently picked up a ProStar 30M and so far I love the unit. It has 3 settings for Gel, Sealed and Flooded batteries depending on what type you are charging at the time.

My question is if I wanted to charge a regular Lead Acid car battery can I with this controller? If so what setting should I have it on?

Now I wont be using these car batteries for anything do to with my solar systems, just wanted to know if I could charge them using my solasr equipment.

Thanks

BB.

Re: Auto Battery and Charge Controller

Yes you can.

Generally a car battery is charged around 14.2 volts (~77F), no equalization, and float around 13.8 or less (check the mfg. website).

Generally, a car battery should not be discharged more than ~15% (85% State of Charge) or so... The plates are very thin and the battery is designed to supply high current for "light" weight (car starting).

WindSun's (NAWS) Battery FAQ is a good place to start.

-Bill

boisblancboy

Re: Auto Battery and Charge Controller

For my controller here are the battery setpoints

GEL Sealed Flooded
LVD 11.4 11.4 11.4
LVD Reconnect 12.6 12.6 12.6
PWM Reg 14 14.15 14.4
Float 13.7 13.7 13.7
Equalization N/A 14.35 14.9/15.1
HVD(solar) 15.2 15.2 15.2
HVD(load) 15.3 15.3 15.3


The Gel is the only one that doesnt have an equalization, but car batteries are not GEL, unless I am completely missing something.

Are you saying contact the company of the battery or the controller?

Also I did go over the battery faqs, I refer to that page fairly often actually.

Solar Guppy

Re: Auto Battery and Charge Controller

Use the Flooded setting, that what a car battery is

boisblancboy

Re: Auto Battery and Charge Controller

I figured it had to be the flooded setting, but I wanted to absolutely sure before I screwed something up!

BB.

Re: Auto Battery and Charge Controller

Just watch the water levels... You are not deep cycling the battery so most of the charging will be the last 2-5% of charge cycle.

Frequent and deep equalization is probably not needed and will just boil off hydrogen mostly.

If the battery is just setting around (waiting for a car to put it in)--then leaving it connected at the float only setting would probably be better for long term/low maintenance setting.

-Bill

boisblancboy

Re: Auto Battery and Charge Controller

I am not sure how to keep it in the float only mode is the only problem.

We own lots of heavy equipment and tend to have a few batteries laying around at one time, so I figured I could either just switch the controller to a different battery every once in awhile or wire them together? Also since I just typed that it wouldnt be a good idea to wire and charge a couple of batteries of different ages together in the first place. Then one battery at a time would suffice i guess.

Being where I live and our job, if we happen to have a battery go bad on us we cant just run to the store and get a new one. So even with some of the old batteries we replace we generally keep them around even if they are not in tip top condition. You just never know when you might need on and hopefully the old one would get us by starting our equipment until we can get a new battery.

BB.

Re: Auto Battery and Charge Controller

I would not have a problem paralleling multiple batteries with 13.7-14.2 volts or so on the solar charger.

You are not deep cycling the batteries--you are just keeping them fully charged.

Just as an FYI--really watch the water levels. I had a small 1 amp maintenance charger on a pair of 12v 100 AH RV batteries. After 6 months of storage--they were boiled dry (yep, my first set of batteries that I quickly killed).

My trick for using cheap 1 amp trickle chargers on batteries in storage (or for cars not driven often)--Get a lamp timer and set it to turn on ~1-4 hours per day--whatever it takes to make up for self discharge and standby loads (Radio, clock, keyless entry, alarm, On-Star, etc.)... Has worked very well on my and my in-laws vehicles.

Then you don't have to remember to plug the charger in 1 day per month, then unplug the next day. I use the same thing for rechargeable lights too--to keep them topped off.

-Bill

boisblancboy

Re: Auto Battery and Charge Controller

Wow pretty amazing 1amp on for two batteries would boil them dry. With the charge controller wont it help prevent that?

BB.

Re: Auto Battery and Charge Controller

I did not check out the battery maintainer's voltage... But, yep, 1 amp 24 hours per day (or in this case across two batteries, the maintainer would cycle on and off on its own)--it is enough.

-Bill