CHARGING TWO BATTERIES DURING WINTER STORAGE HELP - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Alfdawg · 12-30-2020, 03:33 AM

I have a duralast platinum agm battery for my primary battery and a xs power xp3000 for my secondary battery for my car audio system. The batteries are wired in parallel. Negative to negative and positive to positive. My question is can I charge both batteries at the same time with a single battery charger? And also since they are two different brands of batteries but both are agm if I charge them together will it harm either battery?

granatl · 12-30-2020, 05:11 AM

Yes. I've done this for the past 1+ year on two high end Odyssey batteries. I'd only run the charger about once per month (90 minute cycle).

Southern Comfort · 12-30-2020, 05:56 AM

Overcharging will harm any battery as in shortened longevity at best, fire or explosion at worst.

Generally batteries truly in parallel need to be the same type and age. Are yours designed to the same specs? If not, one will overcharge while the other charges.
If that is the case then they should be isolated when charging

Sure, you can charge them as they sit. In fact you charge them together now whenever then car is running.

Another important consideration is what type battery charger you plan to use and how long will they sit on them charger? Battery tender or charger? There are ton of info on the internet about which to use in your situation.

Camaro2ss2010 · 12-30-2020, 07:52 AM

It is ok to charge them at the same time. My diesel has dual batteries that are parallel for charging, running, etc.. all the time. As mentioned above I do replace both when I replace one just to keep them the same age.

CamaroCracka · 12-30-2020, 08:12 AM

I've been running dual batteries on my 02 Silverado for about 12 years just cabled in parallel. I've replaced the primary once and the secondary twice. It's possible for one battery to go bad and take out the other over time, but I wasn't going to try to find a Duramax dual battery rig with the factory relay setup from a junk yard. I was only able to fit a battery that is about 100 CCA less than the factory one, but it helps with the electric winch and off-road lights.

I don't use a battery tender on it, but I do charge it with a charger from time to time if I'm not driving it much. I'm sure it shortens the life of the smaller battery, but not by enough to make me do it the way the factory does.

I also have a DMax and I did change both batteries together on that because it's the DD and I want it to be 100% dependable. I did not change both batteries when one went dead on a Cummings I used to have, but the batteries were easier to change on it so I was less concerned about having to do it on the road.

Alfdawg · 12-30-2020, 10:42 AM

Quote:

Originally Posted by Southern Comfort

Overcharging will harm any battery as in shortened longevity at best, fire or explosion at worst.

Generally batteries truly in parallel need to be the same type and age. Are yours designed to the same specs? If not, one will overcharge while the other charges.
If that is the case then they should be isolated when charging

Sure, you can charge them as they sit. In fact you charge them together now whenever then car is running.

Another important consideration is what type battery charger you plan to use and how long will they sit on them charger? Battery tender or charger? There are ton of info on the internet about which to use in your situation.

I was told by a Xs power rep to get at a 15 amp battery charger to charge both batteries and remove the charger once the batteries are charged. And to charge them at once a month.

Alfdawg · 12-30-2020, 10:43 AM

And I brought both batteries at the same time. So does that mean they are the same age?

Alfdawg · 12-30-2020, 10:51 AM

Quote:

Originally Posted by Southern Comfort

Overcharging will harm any battery as in shortened longevity at best, fire or explosion at worst.

Generally batteries truly in parallel need to be the same type and age. Are yours designed to the same specs? If not, one will overcharge while the other charges.
If that is the case then they should be isolated when charging

Sure, you can charge them as they sit. In fact you charge them together now whenever then car is running.

Another important consideration is what type battery charger you plan to use and how long will they sit on them charger? Battery tender or charger? There are ton of info on the internet about which to use in your situation.

My primary battery is 80 amp hours and 140 reserve mins and my secondary battery is 120 amp hours and 240 reserve mins. So do you think I can charge them together safely?

Southern Comfort · 12-30-2020, 01:40 PM

Quote:

Originally Posted by Alfdawg

My primary battery is 80 amp hours and 140 reserve mins and my secondary battery is 120 amp hours and 240 reserve mins. So do you think I can charge them together safely?

Personally, I would not design anything to run or charge unmatched batteries in parallel.

Given no other choice, then I’d charge them slowly using a battery tender or low amp AGM charger and remove charger when fully charged.

Batmanntexas · 12-30-2020, 03:39 PM

You could always get a dual battery tender. You can remove one of the battery ground cable clamps and charge both batteries at their needed rate. I think I got the one for my boat at Harbor Freight for about $50.

Camaro2ss2010 · 12-30-2020, 06:29 PM

Quote:

Originally Posted by Alfdawg

And I brought both batteries at the same time. So does that mean they are the same age?

There should be dated stickers/codes on the batteries.

12-30-2020, 03:33 AM	#1
Alfdawg Drives: 2014 camaro ss Join Date: Oct 2018 Location: Southfield Michigan Posts: 126	CHARGING TWO BATTERIES DURING WINTER STORAGE HELP I have a duralast platinum agm battery for my primary battery and a xs power xp3000 for my secondary battery for my car audio system. The batteries are wired in parallel. Negative to negative and positive to positive. My question is can I charge both batteries at the same time with a single battery charger? And also since they are two different brands of batteries but both are agm if I charge them together will it harm either battery?

12-30-2020, 05:11 AM	#2
granatl Drives: 2SS RS ABM A6 Join Date: Jun 2010 Location: Pahrump, NV Posts: 273	Yes. I've done this for the past 1+ year on two high end Odyssey batteries. I'd only run the charger about once per month (90 minute cycle). __________________ Jack Bilger

12-30-2020, 07:52 AM	#4
Camaro2ss2010 Drives: 2010 Camaro 2SSRS M6 Join Date: Jan 2019 Location: Alabama Posts: 1,249	It is ok to charge them at the same time. My diesel has dual batteries that are parallel for charging, running, etc.. all the time. As mentioned above I do replace both when I replace one just to keep them the same age. __________________ ECS supercharger, custom ground cam, ported throttle body, long tube headers, aeromotive fuel pump, fic injectors, ATI super damper, Corsa Extreme exhaust, elite engineering catch can and many other things.

12-30-2020, 08:12 AM	#5
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 2,736	I've been running dual batteries on my 02 Silverado for about 12 years just cabled in parallel. I've replaced the primary once and the secondary twice. It's possible for one battery to go bad and take out the other over time, but I wasn't going to try to find a Duramax dual battery rig with the factory relay setup from a junk yard. I was only able to fit a battery that is about 100 CCA less than the factory one, but it helps with the electric winch and off-road lights. I don't use a battery tender on it, but I do charge it with a charger from time to time if I'm not driving it much. I'm sure it shortens the life of the smaller battery, but not by enough to make me do it the way the factory does. I also have a DMax and I did change both batteries together on that because it's the DD and I want it to be 100% dependable. I did not change both batteries when one went dead on a Cummings I used to have, but the batteries were easier to change on it so I was less concerned about having to do it on the road. __________________ 2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes.

12-30-2020, 03:39 PM	#10
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	You could always get a dual battery tender. You can remove one of the battery ground cable clamps and charge both batteries at their needed rate. I think I got the one for my boat at Harbor Freight for about $50. __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

12-30-2020, 05:56 AM	#3
Southern Comfort No Tags/Habitual Violator Drives: 2012 SIM 2SS/RS & z71 Join Date: Sep 2011 Location: North Georgia Posts: 2,379 View My Garage	Overcharging will harm any battery as in shortened longevity at best, fire or explosion at worst. Generally batteries truly in parallel need to be the same type and age. Are yours designed to the same specs? If not, one will overcharge while the other charges. If that is the case then they should be isolated when charging Sure, you can charge them as they sit. In fact you charge them together now whenever then car is running. Another important consideration is what type battery charger you plan to use and how long will they sit on them charger? Battery tender or charger? There are ton of info on the internet about which to use in your situation.

12-30-2020, 10:43 AM	#7
Alfdawg Drives: 2014 camaro ss Join Date: Oct 2018 Location: Southfield Michigan Posts: 126	And I brought both batteries at the same time. So does that mean they are the same age?