Charging 24v series with 12v question ?

[Daniel262]

I am wanting to charge my batteries on my MEP-003a and I am going to use two 1.5a batt maintainers , ? Do I have to disconnect the cable between the 2 batts (series) or can I just put one charger on each batt without damaging the chargers and/or batteries and Leave the 24v series intact ? Thank You . P.S. These are the mil-spec brown square batteries that came with the genny and they have ship date june 2013 so I don't want to ruin them $$$

 

[steelandcanvas]

I put (2) 12 volt chargers on my 003A and disconnect the "dogbone". You'll have folks say you don't have to disconnect it, but with disconnecting it before starting, it forces me to do my pre-op checks. Not only that but I have an aversion to putting positive and negative on essentially the same terminal.

 

[Triple Jim]

In case you haven't bought the 12V chargers yet, they're available reasonably in 24V versions, probably because of the wheelchair market.

 

[Daniel262]

I put (2) 12 volt chargers on my 003A and disconnect the "dogbone". You'll have folks say you don't have to disconnect it, but with disconnecting it before starting, it forces me to do my pre-op checks. Not only that but I have an aversion to putting positive and negative on essentially the same terminal.

Thanks , I feel the same way about -/+ meeting in the middle something just does not feel right about that , I have three battery 12v trickle chargers and don't want to buy another , Thanks

 

[cuad4u]

Put one of the heavy duty knife switch battery cut-off's between the two batteries. When it is time to charge the batteries use the two 12V chargers and open the knife switch. When you are finished charging, close the knife switch for normal operation. This will make isolating the two batteries easy and will reduce (eliminate) wear and tear on the battery terminals and connectors by constantly removing and reinstalling them.

 

[steelandcanvas]

This will make isolating the two batteries easy and will reduce (eliminate) wear and tear on the battery terminals and connectors by constantly removing and reinstalling them.

I don't have to remove the lead terminals, I have the "marine type" with the threaded stud and ring terminals on the dogbone. I just remove one wingnut, slide the cable out of the way and put the charger's clamps on. Good thought though for set ups with the regular clamp style lead terminals.

 

[Chainbreaker]

You could do it the way I did (link below), however it is not absolutely necessary to isolate each battery when using 12v chargers to each. The charger's terminals only see what is connected between them (at least that is how my BatteryMinder 1500's operate, call your battery charger's mfg's customer support to confirm as that is what I did). With that said, it is always best, and stated in the TM, to have the batteries disconnected when not in use.

Regarding using (2) 12v charger Vs a single 24v charger - I prefer to use (2) 12v chargers/maintainers instead of a single 24v charger. With the batteries isolated via (2) 12v chargers each charger is reacting to each individual battery's charge state/condition. In that configuration if one of the batteries has a shorted cell or is older than the other, etc. a 12v maintainer/charger will only react to the condition of the battery it is connected to. One charger could indicate a fault condition on a failing battery while the other charger is in the green.

http://www.steelsoldiers.com/showth...Crossover-Lead-Idea-for-generators&highlight=

 

[bchauvette]

There is no need to disconnect the "Dog Bone" between the batts.

 

[kloppk]

Some battery chargers have their Negative output connect to the AC line cord ground pin.
IF the battery chargers have a 3 prong plug AND it's outputs are isolated from the line cord ground pin then there is not need to disconnect the cable(s) from the batteries.
If the chargers Negative outputs are not isolated from the line cord ground you need to either disconnect the batteries or you can put a cheater on the line cord plug to change it to a two wire connection to the outlet to isolate it's ground.

I found out the hard way last week and let the "magic smoke" out of one of my chargers due to it's internal negative output to AC ground connection.
Fortunately it only burned a trace on the chargers PWB and was easily fixed.