Can you run a lithium battery and dc battery in parallel?

mjfwv

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Dec 19, 2019
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Can you run a lithium battery and dc battery in parallel?
 

Burgess

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Apr 10, 2006
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USA
Short answer:

NO


Longer answer:

HELL NO ! ! !



Welcome to CandlePowerForums !

:welcome:
 

josiahg52

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May 23, 2018
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Sorry, I'm not being disingenuous, but aren't all batteries DC?
Is it a US expression that I haven't learned yet?
P

I was thinking the same thing. In any case, it's generally not wise or advised to run cells/batteries of different chemistries or cells/batteries of vastly different age or condition in series OR parallel.
 

RetroTechie

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@mjfwv:

Please define "run".
What lithium battery? (chemistry / brand / type / size / # of cells in series or parallel)
What DC battery? (same)

If with "run" was meant "discharge" (use), then YES. For example with a diode in series of each battery & using batteries with roughly equal voltage & current capability. This has some drawbacks though - therefore more details needed.
If "direct connect, charge and discharge" was meant, then NO. Different chemistries need different charging methods. Serious troubles may result if eg. lead-acid or NiMH charging method is applied to Li-ion battery. Differences in voltage / capacity / current capability only makes this worse.

In general if 1 battery doesn't suffice then a) use a bigger battery, or b) use more of the same batteries in series or parallel.
 

Katherine Alicia

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Yes you can, I used to do it quite regularly as backup power for CMOS SRAM.

Edit: it might be worth a mention that if you Did go the Diode route, there will be a 0.7v drop across it, so your 3v will be more like 2.3v ;)
 
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