Can I charge multiple batteries at once?

[IXLR8]

A word of caution, when I worked at Sears years ago... we had a bank where we had 15-20 batteries in parallel on charge at once. This was to keep the new batteries topped off before putting them in a car. All different sizes and capacities. I was not there at the time.. but somebody was not paying attention and hooked a battery up backwards.. can you say KABOOM. 15 batteries x 500 amps each dumping into one battery!!
Guy spent several days in the hospital, battery bank was removed.

 

[RalphVa]

I keep two 12v utility batteries in parallel charged up with my solar panel this time of year. It's the panel, and one of the batteries, normally used to run my fence charger during gardening season. I occasionally run something off the batteries using an inverter, to use them a little bit.

Ralph

 

[SPYDERLK]

Yes, starter batteries are paralleled in diesel vehicles.
There has been MUCH theoretical discussion about this over the years, but they tend to NOT discharge into each other - at least mine never have. As a pair they last about as long as a single battery on a gas car, but it is recommended to replace them in pairs anyway.

When you starthaving trouble with a pair like that you find that only one is bad.
larry

 

[al b]

When i t comes to flashlights I check each battery with a voltmeter when the light gets weak and usualy find only one is down out of five, two the most. replace the bad ones and I'm good again. And it will last a while too.

 

[aczlan]

When you starthaving trouble with a pair like that you find that only one is bad.
larry

I would beg to differ somewhat, my parents have a '99 E350 (have had it since '01) with the 7.3L Turbo Diesel engine, it has dual batteries, one in the engine compartment and one on the framerail under the first bench seat. when one goes bad, the other is never far behind (not usually completely dead, but not far from it), a while back we started getting 3 year batteries @ walmart (Everstart N-65s IIRC) they have ~800 CCA and the pair generally lasts 2 years, after that one dies and the other is bad enough that walmart replaces both of them. the best part is that they provide free installation/replacement so I/we no longer have to hold a 20+lb battery 2' off the ground with one hand while bolting it on with the other , it is slightly easier to put it up with a jack, but it is still a PITA (Pain In The Arm) to get the bolts and brackets to line up.

Aaron Z

 

[SPYDERLK]

I would beg to differ somewhat, my parents have a '99 E350 (have had it since '01) with the 7.3L Turbo Diesel engine, it has dual batteries, one in the engine compartment and one on the framerail under the first bench seat. when one goes bad, the other is never far behind (not usually completely dead, but not far from it), a while back we started getting 3 year batteries @ walmart (Everstart N-65s IIRC) they have ~800 CCA and the pair generally lasts 2 years, after that one dies and the other is bad enough that walmart replaces both of them.Aaron Z

Thats a very short life for a three year battery. If you were to bring the electrolyte to the proper level and give each a slow charge separately you would find one of them to be ok. It could be used in a single battery vehicle but not dually because it would not match. Using batteries dually without diode protection to prevent the strong one from discharging thru the weaker is a crapshoot and generally abusive to the batts. Thus less life, especially if the vehicle is not regularly driven. Im already on the 2nd set in my 06' Dodge - first set didnt last a year. When these go out I will replace them with a 1000CA single. With the 5W40 Rotella the engine cranks easy.
larry

 

[tallyho8]

I use the Walmart 3 year free replacement batteries in my 1995 F250 diesel too. I bought a pair of them in 1998 and they went dead in 2000 2 1/2 years later. I brought them back and got 2 new ones and a NEW 3 year guarantee. I returned these in 2003 for 2 free new ones and again in 2005 for 2 more free new ones. The last set was still good and I forgot to return them within the 3 years so now I am going to have to buy 2 more before long. But over 10 years of batteries for a one time price was pretty good.

 

[aczlan]

Thats a very short life for a three year battery. If you were to bring the electrolyte to the proper level and give each a slow charge separately you would find one of them to be ok. It could be used in a single battery vehicle but not dually because it would not match.

that may be, however being as Walmart is replacing the batteries for free (and installing the new ones, also for free) we haven't had a need to go that route.

Aaron Z

 

[SnowRidge]

.................Thus less life, especially if the vehicle is not regularly driven. Im already on the 2nd set in my 06' Dodge - first set didnt last a year. When these go out I will replace them with a 1000CA single. With the 5W40 Rotella the engine cranks easy.
larry

That doesn't sound right.

I have an '05 Dodge diesel with twin batteries. I bought it in September of '05, but it was built in January of February of that year, if I recall correctly. It doesn't get a lot of use, having under 13K on the odo. Despite the fact that it has been mostly sitting for almost four years, the original batteries are fine, and I had no trouble starting it when it got down in the 20's a few days ago.

Have you checked the charging voltage on your '06 to see if it is within spec?

 

[Bedlam]

Tally
did the pro rate those at wal mart or just even exchange?Ive had good luck with a wal mart battery in my tractor for 5 years now. Hmm I can hear it dieing now (I jinxed myelf) lol