Question on batteries...

shaker · Posted: Tue Jan 26, 2010 6:37 am Post subject: Question on batteries...

I don,t know if anyone ever asked this qusetion yet but...
Would it be possibe to mix battery sizes & brands in a vehicle...
I have 3 3800 kinetic,s but i am not getting anymore to buy so can i use smaller ones in the same brand or some in a different brand....

madaz · Posted: Tue Jan 26, 2010 9:46 am Post subject:

its never recomended!

t&t tech · Street 2NR Joined: 30 Dec 2009 Tech posts: 82 My 2NRide:

Never!

kurpal_v2 · Posted: Tue Jan 26, 2010 8:27 pm Post subject:

Why?

I view this rule as a marketing ploy.

Show me the light.

kool as can be · Posted: Tue Jan 26, 2010 8:30 pm Post subject:

The mix brand will have difference in charge rate and that could cause problems i would go with one brand its better that way.

kurpal_v2 · Posted: Tue Jan 26, 2010 8:35 pm Post subject:

^^

But if I have a battery upfront with a 55ah rating and one in the back with a 85ah rating from the same company. Isn't that the same situation?

kurpal_v2 · Posted: Tue Jan 26, 2010 8:40 pm Post subject:

kool as can be, you not too much off eh. If you said you would use the same model battery in a battery bank then I can understand the batteries having to be consistant properties.

But outside the battery bank scenario I believe the "charging rate/ same brand battery" to be a marketing strategy.

t&t tech · Street 2NR Joined: 30 Dec 2009 Tech posts: 82 My 2NRide:

Always match battery types, down to the age, type and characteristics, WHY?
This extract is taken directly from kinetik's website!
Mixing Different Battery Technologies
Kinetik Power Cells are compatible with most standard 12 volt charging systems and battery technologies. We do however advise using Kinetik Power Cells exclusively throughout the vehicle for maximum voltage, performance and longevity of aftermarket electronics as well as the Power cells. This will minimize self discharging of the power storage devices in the vehicle while not in use also. Kinetik Power Cells have a very low self discharge rate much lower than that of a standard ‘wet cell’ car battery.
When different types of power storage devices (batteries or Power Cells) are used in parallel in an electrical system, current will have a tendency to flow between storage devices unnecessarily resulting in heat build up and loss of power where it is needed most. When Kinetik Power Cells are used throughout the install, current will flow directly from the Power Cells to the load in a balanced manner minimizing ‘fighting’ between unlike storage devices.

kurpal_v2 · Posted: Tue Jan 26, 2010 8:52 pm Post subject:

t&t tech, so using one brand of batteries minimizes flow of current across batteries?

Also how does that help me in my 55ah/85ah scenario? Does it mean I either modify my stock battey mount up front or limit myself to my rear battery in order to match charging rates?

jeffrie88 · Posted: Tue Jan 26, 2010 9:55 pm Post subject:

My buddy has dual batteries and his aren't the same. His system has been going for 2 years now without any problems. The one in the engine compartment is an optima and the one he has in his trunk is a Marine deep cell. They are the same amperage is all. If that is what you are referring too? His system has an isolator though. The same type used in motor homes. That is what keeps the batteries fully charged.

t&t tech · Street 2NR Joined: 30 Dec 2009 Tech posts: 82 My 2NRide:

Have you ever seen a solar system, one with banks and banks of batteries? Have you ever seen an isolator on them? No, because batteries will charge identically, while at the same time sharing the source current. (total source current in milliamps, divided by the number of batteries) If you use two identical batteries, one alone with a full charge will accept MAYBE a few hundred milliamps of charge current from the alternator, so, if you double this load to two batteries, you are looking at maybe one amp of total current required to keep the batteries topped off. The alternator is supposed to supply all of the power for accessories, right? With a 200 amp alternator, this will leave 199 amps to run your system and accessories and engine. Plenty. BUT this is also why it is imperative that you use identical batteries. If you do not use identical batteries the battery with the LOWER internal resistance will try to keep itself charged off of the battery with the HIGHER internal resistance, thus causing reduced battery life for at least one of the batteries. Also, the internal resistance of a lead acid battery varies depending on the state of charge, so you will never be able to tell exactly which way this process will go. Just use identical batteries,and you will not have to worry about any of these issues.

t&t tech · Street 2NR Joined: 30 Dec 2009 Tech posts: 82 My 2NRide:

The lifespan of the batteries will shorten, but as mentioned by jeffery's example with his friend, it may not be significant to an individual!

kurpal_v2 · Posted: Tue Jan 26, 2010 10:23 pm Post subject:

t&t tech, soooooo You backed up my view wrt battery banks. Kudoes.

But in this case

jeffrie88 · Posted: Tue Jan 26, 2010 10:31 pm Post subject:

Also he runs his system off of the battery in the trunk leaving the front battery to handle everything else like starting.

t&t tech: you are probably right. It sounds logical anyways. This may be for typical batteries with the way the lead and acid work. But for the gel cells it is different due to what they use? Plus I think there isn't any issue with ventilation. My opinion would be to use Absorbed Glass Mat or AGM's. Which are the best to me.

kurpal_v2 · Posted: Wed Jan 27, 2010 9:28 am Post subject:

Bump for the iasca stock guys

t&t tech · Street 2NR Joined: 30 Dec 2009 Tech posts: 82 My 2NRide:

Notice my second post! I didn't only say BRAND! I also said age and characteristics! Which would encorporate capacity, in regards to your given situation of 55ah /85ah scenario! So that scenario goes out the window, why, read the last paragraph of my second post!

As regards to your third post where you asked about modifying the battery, no, the solution is simple, you'll be purchasing two brand new batteries, of the same age,type and capacity! Period!

Of course as i said earlier, this isn't mandatory, the only thing is you'll be replacing batteries alot earlier than you're supposed to!