Battery charging

[southpennrailroad]

I have a converted cargo trailer and just this past week on a trip to Caladonia State Park near Gettysburg, I decided to buy a trolling battery to use only for an i-pod docking station, fan and charging the two LED strip lights. My question is should you not charge this battery once your finished with it or should you totally discharge it and have an extra one to use while the first battery is being charged. I was told by two campers that it should be totally discharged. Is the battery also able to be charged while using it with a top off charger? Thanks for your help.

[Dale M.]

If its a nickle-cadmium battery its usually a good policy to run it down totality and then recharge (prevents "memory cycle" of partial recharges)...........

IF its a lead acid, for all practical purpose, it really does not matter, so don't discharge it....

Bottom line, it should be fully charged when put into "storage" , even a 1 amp (or less) trickle charger would not hurt to keep connected to keep it topped off......

http://www.batteryfaq.org/

A "top off" charger is going to take days to build a full charge, but if you got the time, it will do..

Dale

[Joe G]

Completely discharging a lead-acid battery is not recommended. The practice of completely discharging a battery before recharging it only applies to NiCad batteries.

Completely discharging a lead-acid battery causes sulfation which can quickly render the battery useless. I have seen brand new batteries that were destroyed by running them down completely only once.

On a similar note, I hope you didn't buy a Wal-Mart "EverStart" brand battery. They seem to have longevity issues. In fact, 4 out of 5 batteries I replace at my shop are EverStarts. So, around the shop, we call them "NeverStart" batteries.

[HossHoffer]

The recommendation for NiCads has been updates in the last few years. Overcharging, slow-charging and overheating are the worst problems. Voltage depression (memory) is seen very infrequently and usually has to have a very repeatable pattern of charge/discharge over a long period. It is now considered ok to charge a NiCad at will, watching out of course for overcharging and overheating. There is no need to completely discharge a NiCad and in fact is recommended not to drop below 1% of charge. 1% is usually where you get the big drop off of voltage. You know, when your tool starts to slow down.

All this after years of being taught that the proper way to handle NiCads was to always completely cycle them down to zero. The Air Force beat that into me like it was the only fact I ever needed to know about aircraft.

Hoss

[Hinermad]

The recommendation for NiCads has been updates in the last few years. Overcharging, slow-charging and overheating are the worst problems. Voltage depression (memory) is seen very infrequently and usually has to have a very repeatable pattern of charge/discharge over a long period. It is now considered ok to charge a NiCad at will, watching out of course for overcharging and overheating.

Hoss,

Very true. The biggest culprit whe it comes to overcharging is that so-called "16 hour charger." It's usually a simple wall-wart with nothing in it to detect when the battery is fully charged and shut itself off. So when somebody charges their flashlight for 16 hours, uses it for a half hour, then hooks it back up to the charger, they're overcharging the batteries and eventually they lose capacity, which acts like a voltage drop.

Dave

[looped]

I have seen these chargers called battery tender II they seem to act like a peak detection charger. are they good to use? the price seems right for them.

Thanks

[Hinermad]

I have seen these chargers called battery tender II they seem to act like a peak detection charger. are they good to use? the price seems right for them.

I've never used one so I can't speak to how well it's made, but the idea is that it monitors your battery and switches from full current charging (which will charge your battery quickly) to float charging (which keeps a full battery full without overcharging it) automatically. It's what you'd want to use if you have a battery that will stay on the charger almost all the time and only get used occasionally. A lot of motorcyclists use them to maintain the charge on their bike batteries through the winter because they can just connect it and forget it.

You do need to make sure you use the right tender for your battery type. You don't want to use a tender for lead-acid batteries with Nicads, for example.

Dave

[ArtMini]

I'm planning on buying a large marine battery for my trailer to run lights, radio and dvd player. I think thats all I'll need, so my question is, will a marine battery last a weekend on a full charge with a total of maybe 10 hours use (between a light/dvd/radio actually on) And once I get home do I charge it for the next use?

Art

I have seen these chargers called battery tender II they seem to act like a peak detection charger. are they good to use? the price seems right for them.

I've never used one so I can't speak to how well it's made, but the idea is that it monitors your battery and switches from full current charging (which will charge your battery quickly) to float charging (which keeps a full battery full without overcharging it) automatically. It's what you'd want to use if you have a battery that will stay on the charger almost all the time and only get used occasionally. A lot of motorcyclists use them to maintain the charge on their bike batteries through the winter because they can just connect it and forget it.

You do need to make sure you use the right tender for your battery type. You don't want to use a tender for lead-acid batteries with Nicads, for example.

Dave

[madjack]

SPR...you probably bought a Lead/Acid (L/A) battery, in which case you never want to go below 50% discharge or you will face an early demise of your battery from the aforementioned sulphation...

Battery tenders are usually low amperage units(below 2A) and are meant to MAINTAIN a batteries charge...not charge a discharged battery...they will charge a battery BUT, if you have a 100A battery, discharged(50%) to 50A, it will take 30 to 50 hours to recharge, depending upon output of the Tender...as far as leaving the Tender hooked up while the battery is being used, you will havvta read the literature that came with the Tender to see if that is feasible...some are meant for that and are usually referred to as a switching power supply (like the WFCO is)...the WFCO can be permanently attached to the battery and should actually be left plugged in and running while the camper/battery is stored...be careful about leaving the Tender connected, it may cause a discharge when unplugged from 120VAC and may burnout if hooked up to 120VAC while the battery is being used to power appliances/lights...since all these chargers are different, you will havvta rely upon manufacturers directions...
madjack

[wlooper89]

Great advice from madjack. I use the charger called Battery Tender II and it seems to work fine. The output is 1.25 amps so it takes a while to charge a depleted battery, but is good to maintain the battery. It senses battery voltage and reduces voltage in three stages so as not to overcharge. Two lights on the unit indicate when the battery charging or is fully charged. It is not designed to power the trailer, only for charging.

When camping I use a WFCO converter that puts out 25 Amps D/C. It can run the trailer lights, etc. and also charge the battery more quickly than the Battery Tender. This is a good unit for a trailer because it senses battery voltage, is three stage like the Battery Tender and also adjusts output for trailer load.

Bill