Second Battery Questions

[SBFandy 10+ year member]

I would try to make sure i stay about atleast 12v while playing

Thanks for the help man!

 

[bgowdy 5,000+ posts]

Thanks for the help man!

No problem... How big is your stock alt

 

[dunerider650 10+ year member]

..........lool

laugh at me...why? stating facts. If you connect two different batteries, in two different charge states, the lesser charged one will benefit from more charged.

quiescent current.....the larger battery has a bigger quiescent current and that's the current that is required to just stay at status quo it will see the smaller battery as a food source.....and then you have a dead battery. I think they should be within 100 amps of each other to connect and connecting a deep cycle battery with a typical lead acid battery...well im not to sure what the consequences would be. Just saying!!

 

[robert420 10+ year member]

you could just mount a second alternator n run that cable straight to the rear battery... less risk for fire, battery drainage, alt. damage n all that kinda ****

 

[bgowdy 5,000+ posts]

laugh at me...why? stating facts. If you connect two different batteries, in two different charge states, the lesser charged one will benefit from more charged.quiescent current.....the larger battery has a bigger quiescent current and that's the current that is required to just stay at status quo it will see the smaller battery as a food source.....and then you have a dead battery. I think they should be within 100 amps of each other to connect and connecting a deep cycle battery with a typical lead acid battery...well im not to sure what the consequences would be. Just saying!!

i agree that this is the rule of thumb. However as i was saying before this is not always true. I have ran mismatched batteries before and i am now. before on a stock alt i ran a duralast gold under the hood, and regular lead acid battery in back as well a deep cycle marine. i never had trouble with them for more then a year. voltage was pretty good considering i had a 100a stock alt(Which i still have and works like new). Even now i still have the duralast gold under hood with a 220a HO alt and in back now i have 3 deka 105ah agm batteries and my voltage rests at 12.8v and runs between 14.6v - 15.0v depending on the temperature. at full tilt with 3850rms @ 1 ohm i stay above 13.7v @ idle.

But i do understand what your saying. that is the "Rule of Thumb".... I was just saying from MY exp.

 

[dunerider650 10+ year member]

i agree that this is the rule of thumb. However as i was saying before this is not always true. I have ran mismatched batteries before and i am now. before on a stock alt i ran a duralast gold under the hood, and regular lead acid battery in back as well a deep cycle marine. i never had trouble with them for more then a year. voltage was pretty good considering i had a 100a stock alt(Which i still have and works like new). Even now i still have the duralast gold under hood with a 220a HO alt and in back now i have 3 deka 105ah agm batteries and my voltage rests at 12.8v and runs between 14.6v - 15.0v depending on the temperature. at full tilt with 3850rms @ 1 ohm i stay above 13.7v @ idle.
I completely get what your saying.... and having done it yourself you would know the "real life" issues that might happen. Ive known people to do it as well...just thought i would get into a bit more detail on the matter for SB since this topic got brought up.

 

[SBFandy 10+ year member]

laugh at me...why? stating facts. If you connect two different batteries, in two different charge states, the lesser charged one will benefit from more charged.quiescent current.....the larger battery has a bigger quiescent current and that's the current that is required to just stay at status quo it will see the smaller battery as a food source.....and then you have a dead battery. I think they should be within 100 amps of each other to connect and connecting a deep cycle battery with a typical lead acid battery...well im not to sure what the consequences would be. Just saying!!

Or i can relay them......

 

[dunerider650 10+ year member]

yep use an isolator....then it doesnt matter.

 

[urmomsmin3 10+ year member]

i just put a 2nd bat in i have a fuse 12 inches from the first bat goin to the second one then another fuse 10 inches from 2nd bat to my amp ground the 2nd bat to the frame or floor w.e just make sure its a good ground

 

[garretttt4 10+ year member]

you could just mount a second alternator n run that cable straight to the rear battery... less risk for fire, battery drainage, alt. damage n all that kinda ****

why would he mount a second alt for a measly 2000 watts? if he was gunna get another alt he could just get one h.o. alt and be more than fine.

 

[JoeK 10+ year member]

yep use an isolator....then it doesnt matter.

Isolators cause more harm to batteries than good. When you instantly charge up that drained battery you are not only causing premature death of the front batt, but increasing the strain on the alternator.