No announcement yet.

What battery

  • Filter
  • Time
  • Show
Clear All
new posts

  • What battery

    I am currently putting together a computer for my truck how ever this is not about that, this about a battery for it all, currently I have a yellow top optima battery and I thinking of getting a blue top for the purpose of having battery when the truck is running (yellow) and one that is for when the truck is off (Blue).

    my question is what do y'all think of having the blue top to run things while the truck is off or should I just buy a red top for starting and running the truck and use the yellow to run things while the truck is off

  • #2
    Just curious, how will you switch between the two? I currently have a yellow top in my Accord, and it has done a great job both when the engine is running and when it's off. Of course, i never really use the pc for extended periods while the engine is off anyway. Are you planning on doing a lot of this?


    • #3
      If you want 2 batteries I would just use 2 yellow tops then. Then between the 2 throw in one of these:

      Yellow tops are designed for deep cycle and starting. Reds are good for starting but don't last long when put into sustained loads (from experience).


      • #4
        Yea the isolator was pretty much the way I was going to go but my reason for suggesting the blue top was that that is what is used in boats to sustain numerous electronics and pumps for an extended amount of time so I assumed that it would be better for use when the vehicle is off for use with the sound system


        • #5
          You'd probably want a deep cycle wouldn't you?

          In either case it may be worthwhile using a low voltage cutout (battery guardian etc) unless the PSU can do that.

          You could use any battery. I was going to suggest not spending the money on an AGM battery, but if it's in the cabin or boot etc, then AGM it is. (Or a gel cel?)

          And if you can connect to the D+ or charge lamp circuit, don't bother with the "smart" isolators - a charge-lamp controlled relay functions exactly the same. (For a heavy relay, maybe use a BW solenoid that is triggered by a smaller relay that is driven by the D+ circuit?)


          • #6
            how long are you planning on running the system for with the engine off? i have run my computer, and 2 audio amps, at adequate levels on a yellow top for at least 2-3 hours with no issues starting afterward.

            it might be a better idea to first try running everything you plan to run with just the yellow top, and see how long it will last, and then if it is really needed, to add another battery later on.
            My OLD 2001 Mitsubishi Eclipse GT:
            "The Project That Never Ended, until it did"

            next project? subaru brz
            carpc undecided


            • #7
              I guess I should try and run the whole thing here at my house to see more or less how long I can run it without having problems starting it up, but also my whole train of thought here is I guess I am just looking to have some sorta back up


              • #8
                Hello, I saw your conversation regarding our batteries and wanted to help out if I could. uknowwhat, unless you want a group 31 BlueTop, our other BlueTops sizes are identical internally to their YellowTop (D27, D34) or RedTop (34) counterparts. You would need to run an isolator anytime you are using batteries that are not identical in size, type and age.

                Although Optima batteries are a sealed, Spiralcell AGM (not gel) design, it is important that any lead-acid battery has proper ventilation. ALL lead-acid batteries can vent gas. Traditional wet batteries do this immediately when recharged, since they are not sealed. Sealed lead-acid batteries like Optimas and all other “dry cell” AGM batteries have safety release valves that should only vent if they are seriously overcharged.

                Under normal operating conditions, an AGM battery will not vent gas. Since alternators or chargers can fail, the safest and correct mounting method for trunks and passenger compartments is to make sure that any possible gas venting will escape to the outside of the vehicle. All vehicles with original equipment battery locations in trunks or passenger compartments will have a vent provision that should be used. If your battery is custom-mounted somewhere in the passenger compartment we recommend venting the battery to the outside of your vehicle as well. Optima group 27, 51, 78, 34C, and 31 batteries all have ports for connecting a vent hose.

                Although people do it anyway, we would never recommend installing an unvented battery in any enclosed space, because there’s a legitimate, albeit unlikely, safety risk involved.

                For example, IF there is a voltage regulator failure, and IF the battery is severely overcharged, and IF this goes unnoticed, and IF the battery vents because the internal pressure exceeds the release pressure of the vents, the gasses are both flammable and toxic. This may sound like a lot of “ifs,” but attorneys and engineers get paid to plan for every worst-case scenario. If you have any other questions, I’ll do my best to answer them.

                Jim McIlvaine
                eCare Manager, OPTIMA Batteries, Inc.


                • #9
                  Glad to see someone else pointing out the venting of AGM batteries.
                  It's cute in combination with thermal runaway that isn't uncommon under those circumstances - NOTING that I am used to dealing with AGM stings of 400VDC etc (12V monoblocks and smaller series strings (including parallel) are a far lesser issue!!).

                  Though like many battery gurus, I do not like parallel batteries except when monitored, else when new. Though that is not so much of a safety issue with only 2 maybe 3 batteries, but more one of lifecycle - 2 parallel batteries have about twice the unreliability of batteries that are separated when idle.

                  Do you have any data/results from parallel versus free standing; and co-housed versus boot & engine bay?


                  • #10
                    Originally posted by OptimaJim View Post
                    unless you want a group 31 BlueTop, our other BlueTops sizes are identical internally to their YellowTop (D27, D34) or RedTop (34) counterparts.
                    Maybe I read that wrong, but if they are identical internally, then what's the difference between BlueTop, RedTop, and YellowTop?


                    • #11
                      OldSpark, as you hinted at, whenever configuring batteries in a string (series or parallel), especially as the bank gets larger, the design of the overall system becomes much more important to the success and reliability of the project. We generally do our testing on individual batteries, because this isolates other variables that may produce skewed results. Regarding installation location, although high temperatures will increase the self-discharge rate of a battery and can reduce service life, extensive fleet testing in Las Vegas has proven time and again that an Optima battery will last up to twice as long as most other batteries, even in areas where underhood temps are over 165F for long periods.

                      kross, all BlueTop batteries come with additional threaded top posts for marine applications. Beyond that, the specifications on our D27M and D34M BlueTops are identical to those of our D27 and D34 YellowTops – these batteries are dual purpose, deep-cycle and starting batteries and are recommended for vehicles with high electrical requirements. Likewise, our 34M BlueTop has identical specifications to our RedTop 34, these are starting batteries and are designed for vehicles with typical/stock electrical requirments. All YellowTops and RedTops come with three year warranties, while BlueTops come with two-year warranties. If you have any other questions, please don’t hesitate to ask.

                      Jim McIlvaine
                      eCare Manager, OPTIMA Batteries, Inc.


                      • #12
                        Jim - the data for parallel versus single - eg, 2 parallel same batch/size Optimas, at whatever temp though 25C (78F?) anticipated, but 165F or similar as a comparison and 78F & 165F parallel (etc) also welcome.
                        Even comparative reliability figures will suffice (MTBF etc).

                        I suspect others (from other forums) would also be interested in your Las Vegas testing with comparison to other batteries etc. For example, a recent poster compared "failing Optimas" to "reliable Kinetik" AGMs.

                        As for long strings (like 36 x 12V monoblocks), it's more a case of monitoring rather than any sort of testing (lol!). Hence at least 12-bit battery monitors etc.
                        But being for dedicated UPS use, normally 10 year batteries were specified, and these would be replaced every 5 years. That was great for those wanting cheap AGM batteries!

                        Update 21Apr2010: No data forthcoming - even for paralleled batteries. Issue closed.