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Old 12-01-2022, 15:15   #1
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Can I run an AGM battery in paralel with a deep cycle Lead Acid? And if not....

Hi all, I am terrible with electrical issues so thank you all for your help in advance. So my question is, I have an AGM battery that currently is my house battery, and now got my hands for free on another lead acid.

100 Aph AGM: https://amzn.to/3tnUsF0
109 Aph Lead acid deep cycle: https://bit.ly/3rkcLbA

Can I run them in parallel to charge off my alternator? Important to know: If its possible but not ideal Im ok with that, I only need this solution to work for about 4 months then will be getting new batteries.

Also wanted to ask if the answer is a definte no...do not use these in parallel...well then my alternator is charging my current house battery, the AGM. If that runs low could I simply disconnect the cable form that battery and attach them to the deep cycle lead acid and run the engine to charge that one if needed in a pinch? and vice versa? Thanks!
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Old 12-01-2022, 16:17   #2
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Re: Can I run an AGM battery in paralel with a deep cycle Lead Acid? And if not....

Not ideal (for a variety of reasons) but possible for the next 4 months.
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Old 12-01-2022, 19:01   #3
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Re: Can I run an AGM battery in paralel with a deep cycle Lead Acid? And if not....

You can do it .
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Old 14-01-2022, 10:55   #4
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Re: Can I run an AGM battery in paralel with a deep cycle Lead Acid? And if not....

Does your alternator even have different charging cycles for flooded and AGM batteries? The big difference is the charging cycle, so as long as you are willing to sacrifice peak battery performance, yes.

Consider the installation of a sophisticated voltage regulator such as the Balmar when you replace the batteries.
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Old 15-01-2022, 05:39   #5
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Re: Can I run an AGM battery in paralel with a deep cycle Lead Acid? And if not....

Quote:
Originally Posted by momo034 View Post
Also wanted to ask if the answer is a definte no...do not use these in parallel...well then my alternator is charging my current house battery, the AGM. If that runs low could I simply disconnect the cable form that battery and attach them to the deep cycle lead acid and run the engine to charge that one if needed in a pinch? and vice versa? Thanks!
Don't disconnet the AGM engine battery with the engine running or you risk blowing the diodes in the Alternator. For 4 months, yes your solution will work.

For longer term, you should add some form of battery monitoring with a shut and cheap ones are available. Also, you could use a VSR to connect the house battery to the engine battery. The VSR will sense when the engine is running by the voltage and connect the batteries. When the engine stops, the VSR disconnects the house bank.

Shout if you need more help.

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Old 15-01-2022, 15:08   #6
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Re: Can I run an AGM battery in paralel with a deep cycle Lead Acid? And if not....

All good answers, thanks everyone. Seems I will likely put them in parallel and let it work for as long as it can. Thanks!
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