Charging TM Batteries in Parallel...

[CN Spots]

Is it possible to charge (or maintain) deep cycle batteries hooked up in parallel or do they need to be charged one at a time? I currently have two Trojan SCS225s that I normally charge one at a time immediatly after a trip and about once a week just to keep them fresh. The other day I noticed that my brother had his two deep cycles hooked up parallel on the charger. He said that he had been charging them like that forever but it just seem like a bad idea to me. THoughts?<br /><br />spots

 

[Dunaruna]

Re: Charging TM Batteries in Parallel...

If they are same type/same size, no problems.<br /><br />Just be aware that if one goes bad, the charger will continue to try and charge it - over charging the good one in the process.

 

[CN Spots]

Re: Charging TM Batteries in Parallel...

Yep, they are. The charger I've got is supposed to detect a bad cell, stop charging and start flashing it's light and cursing or something. Hopefully it's smart enough to prevent boiling em dry. Thanks!<br /><br />spots

 

[LubeDude]

Re: Charging TM Batteries in Parallel...

I too have Trojans and have been charging them together all last year with no problems.

 

[--GQ--]

Re: Charging TM Batteries in Parallel...

You can charge as many batteries in PARALLEL as you like. It can be of different brands (not good idea for an unqualified person) , but the ratings must be the same.The question now is your charger designed to charge mulitple batteries. Most exspensive chagers are more than capable. On the other hand you might shorten the life span of cheaper models/brands.<br /><br />Electricity is a dumb creature. If you can provide a path, it will flow until the potential between point of origin and point of distination is reached. It doesn't distinguish between batteries, light bulbs or anything else for that matter. Anything in its path is just a load to be served.

 

[Texasmark]

Re: Charging TM Batteries in Parallel...

I'd say that the specific gravity of each would determine the difference. The battery charger will put out a certain voltage and current, as mentioned, depending upon it's capabilities.<br /><br />Current will only stop when all batteries are at the required specific gravity (corresponding to a specific voltage) to satisfy the fully charged voltage rating of the charger.....if the charger is designed to shut it (current) off. Most newer chargers for small amperage applications will do this.....not the old humongus 200 amp fast charge dudes.<br /><br />Some batteries will charge faster than others depending upon their internal impedance, which determines their current level, which is determined by design and age related deterioriation.<br /><br />And some chargers don't drop off in current (adequately) as the battery approaches full charge causing boiling off and loss of water.....and if you boil off your water in one it will never charge so that is a runaway effect. <br /><br />If you are an amperage watcher, as I am, you are expecting the amperage to go to zero after a reasonable time.....then after a few hours of charging the amperage goes up rather than down...baby you have problems then.<br /><br />So, as stated, one batt may charge faster than the other and then "boil" while the other is coming up to speed and this may require you to attend to the fluid level to keep it up. Can't do this on sealed batteries unless you can get the lid off.....I like non sealed ones. I like to be able to monitor and attend to my fluid levels.....failure to do so is sure destruction for the battery.<br /><br />My experience in charging used trolling motor type deep cycle batteries is not a rosy one. They just act weird to me as compared to monitoring the charging of a regular lead-acid storage battery.<br /><br /><br />One last thing. Charging batteries produces hydrogen gas which will explode if you get the mix right and add a spark. So be careful and use plenty of ventilation. I like to unplug the charger from the wall or turn it off (if you can) before removing any battery connections so as to not get this spark.<br /><br />My2c<br /><br />Mark