Using multiple batteries

Discussion in 'Electrical & Radio' started by crzyhawk, Aug 27, 2008.

  1. crzyhawk

    crzyhawk Well-Known Member

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    Does anyone have any advice on the best way to hook up multiple batteries? I want to use NiHM packs in my cruisers and carrier, and will probably go with three 7.2 volt packs. I wish to use all three packs for drive and pump (Don't want to get pounded with no drive, while still pumping hard, or sink with plenty of speed and no pump; I'm an all or nothing guy), but don't know the best way to hook them all together. Any advice as to what works best with multiple batteries would be greatly appreciated.
     
  2. rarena

    rarena Well-Known Member

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    I like to make up a wiring harness that has them in parallel but I can change them out if needed. I use all tamiya connctors
     
  3. wrenow

    wrenow RIP

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    Ditto - in Lake Shore, I use 2 7.2v batteries, in Dunkerque, 4. A couple of Tamiya "Y"s and you are good to go.

    Cheers
     
  4. crzyhawk

    crzyhawk Well-Known Member

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    Do the NiMHs need to be drained before you can recharge them? What kind of things are important to know about this battery type? After laying out some more things in my Belleau Wood hull, it looks like it will only be two packs instead of the three I originally envisioned.
     
  5. JohnmCA72

    JohnmCA72 Member

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    make sure that any batteries that are wired together are exactly the same type, size, brand, & model. In other words, don't mix batteries. Mixing batteries will almost always result in 1 battery discharging through another because they drain at different rates. This will do you, the user, no good. It can also cause severe damage in some extreme cases. The only exception would be where they are on different circuits that are isolated from one another (such as 1 that powers the receiver only, while other(s) power motors, pump, etc.).

    JM
     
  6. crzyhawk

    crzyhawk Well-Known Member

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    Thanks for that tip, I didn't know. While I would have certainly preferred to keep them the same brand type and model, had you not told me, if I found I didn't like them they might have gotten mixed. Now I know I'll have to always buy packs of 2 and keep them together.
     
  7. the frog

    the frog Member

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    Mike ,2 4200 nimhs in parallel will work fine it does for me .I still prefer 1 10ahr {10,000} nimh pack made from bulk cell purchase Or two 5000 . If you order them with tabs you make up a pack and then dip it.
     
  8. crzyhawk

    crzyhawk Well-Known Member

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    What about charging? Do they need to be run down all the way before you can recharge them?
     
  9. warspiteIRC

    warspiteIRC RIP

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    NIMH batteries do not need to be drawn down all of the way nor do they have a memory so they do not need to be cycled. As far as in Parallel, as long as they are only connected shortly before battle the difference in internal resistance should not allow them to discharge into each other over such a short period of time. Leaving them connected in parallel for long periods of time, without use would have some discharge as one leaked into the other. Under use however, should not have this problem as each are drawn down with the current drain and have no opertunity to discharge into each other.

    Marty Hayes
     
  10. crzyhawk

    crzyhawk Well-Known Member

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    Thanks Marty! I've been thinking about kicking the SLA from my Invincible to the curb as well. If my NiMH experiment works out as well as I am expecting, I think that might be exactly what I do.
     
  11. HMCS

    HMCS Active Member

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    Little Rock is using two high discharge 4600mah packs. Upside is one pack weighs less then half of a 6v 5amp and is about 1/3 the size. Downside is they run 59.99. The two batteries and computer charger ran me 225 bucks with shipping.
     
  12. crzyhawk

    crzyhawk Well-Known Member

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    Ouch last week I ordered two 4500 mha packs and two chargers for $106. I wonder if I bought junk.

    This is what I bought:

    Tenergy Propel 7.2V 4500mAh (45A Drain Rate) Nimh Battery Packs with Tamiya Connectors

    Part#: 11206

    (Qty: 2 x $37.99)

    12V 300mA Charger for 6.0V - 9.6V Batteries with Standard Female Tamiya Connector
    -

    Part#: 01009

    (Qty: 2 x $9.95)
     
  13. HMCS

    HMCS Active Member

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    I'm sure if I had really looked I could have found some cheaper,however this hobby shop is the next province over so I don't mind paying more because the last little while it seems to take forever to get anything from the States(My BC order sat in Customs for 9 days! my HobbyLobby order of Speed 300/400 motors for 7 days!)the packs are pre-made and the cells are EP4600's,the pack is called "Nuclear Power". They are used for RC racing cars/boats. 59.99 is the Canadian price, but still with the exchange would be like 50 bucks, The charger was a big ticket item, I could have gone with a simple plug in and charge one for a lot cheaper, but this one is fully digital with computer display. It has 6 different memory settings and allows you to program everything such as wether the battery is NiCad or Nimh,how many amps you want to charge at,safety timer,peak detection etc...

    One more piece of info I did not know before, in my charger manual it says that you should set the charge for Nimh's 110%-130% over their capacity,they even provide nice charts listing the settings for different types/capacity of batteries. Another tip they provide is that heat damages Nimh cells,so if you feel the pack starting to heat up you should disconnect, let cool, and then reconnect.
     
  14. HMCS

    HMCS Active Member

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    I will also add that I'm not trying to be high-tech or fancy. I just have little knowledge when it comes to Batteries and I figured it would be better to pay more for a charger rather then replace battery packs if I mess them up.
     
  15. warspiteIRC

    warspiteIRC RIP

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    Mike et. all

    Look into the Prophet AC/DC charger by Dynamite 1, 2, 4 amp selectable computer charger about $39.99 retail for all of your CA and NIMH batteries including your receiver.

    Marty Hayes
     
  16. HMCS

    HMCS Active Member

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    The one I have is the Onyx 220,it will charge anything 4-8 cell at 0.1-5.0 amp. It probably is a bit much for my needs, but is very user friendly. It also has a car adapter so you can plug it into your car lighter, as well as a 12v lead so that you can hook it up to a 12v battery and charge at lakeside.It was 59.99 Canadian as well.
     
  17. HMCS

    HMCS Active Member

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    And by anything I mean NiCad/Nimh
     
  18. JohnmCA72

    JohnmCA72 Member

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    I like SLAs, where I have enough weight allowance to use them. They tolerate abuse very well (what is this sport, if not abuse of equipment?), & the cheapest motorcycle charger works just fine. For a bigger ship that needs the ballast, they're hard to beat.

    JM
     
  19. djranier

    djranier Well-Known Member

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    I use those propel batteries, they work great so far. I used them all week long at Nats. Don't know about those chargers you got.
     
  20. crzyhawk

    crzyhawk Well-Known Member

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    The chargers were cheap ones just so I had a means to charge and use the batteries. It sounds like the way to go is to get one of the nice computerized chargers.

    David, is there anything I should know about preparing the batteries like waterproofing, etc?