Batteries..basic charging question

[Delaware]

I have two deep cell batteries in my motorhome. In the Winter I remove them and bring them home. I alternate charging them. My question is can I hook them up in series to the charger and keep them both charged? I also use them to run my Quadrafire pellet stove if the power goes out [this happens fairly often in my area.] They need to be in "ready" mode all through the Winter. Thanks.

[Inland RV Center, In]

Originally Posted by Delaware

I have to deep cell batteries in my motorhome. In the Winter I remove them and bring them home. I alternate charging them. My question is can I hook them up in series to the charger and keep them both charged? I also use them to run my Quadrafire pellet stove if the power goes out [this happens fairly often in my area.] They need to be in "ready" mode all through the Winter. Thanks.

What voltage are the batteries?

What output voltage does your charger provide?

If the batteries are 12 volts DC and the charger is 12 volts DC, then you can charge them together, but they must be in parallel, not series.

If they were in series, you would need a 24 volt DC charger.

If your batties are 6 volts DC, and the charger is 12 volts DC, then and only then, can you charge them in series.

Andy

[Delaware]

Thanks Andy.

[Mexray]

what Andy says is of course correct...

heres another way to look at it (assuming we are talking of 'paired' batteries of the the same group size and voltage):

SERIES connection is when you hook the POS on one battery to the NEG on the 2nd battery - the battery VOLTAGE will be DOUBLED and the AMP HOUR rating will be the same as the rating of one of the batteries.

PARALLEL connection is when you hook the POS of one battery to the POS of the 2nd battery, and likewise, the NEG terminals are hooked to each other - the battery VOLTAGE will be the same as one of the batteries, and the AMP HOUR rating will DOUBLE the rating of one of the batteries.

6 volt - SERIES - 6 volt = 12 volts

12 volt - PARALLEL - 12 volt = 12 volts

another often overlooked situation concerning PARALLEL battery systems, is to try and hook the LOAD CABLE (POS) to one of the batteries - and - hook the GROUND CABLE (NEG) to the OTHER battery...some of our AS's don't really allow this type of connecting due to battery boxes being separated from each other - but if you have your batteries mounted beside each other, try to hook LOAD and GROUND cables to alternate batteries...

There is a slight inherit RESISTANCE in each cable connection, and by hooking the POS & NEG supply cables to alternate batteries, you tend to EVEN OUT this RESISTANCE to help insure both batteries are charged and discharged evenly...