48 volt Big Battery and Lifepower 4 connection

I have a Big Battery HSKY, and want to expand my battery bank. But, I don't want to buy another Big Battery, as they are very expensive at nearly $2500, and I can drive down to Signature Solar and get one of the LifePower's for $1499.
My question is, can I connect the big Battery and the LifePower in parallel to expand my system? If so, how exactly do I do that?
I'

If same voltage, yes.

(+) to (+)
(-) to (-)

(+) to system from one battery
(-) to system from the other battery.

Use the fattest/shortest cables you can to join them.

Do you mean the cells the same voltage, nominal?
The HSKY is 103 amp hours
The LifePower from Signature Solar is 100 amp hours.

When connecting will I have 204 total amp hours, or will the smaller battery throttle it back to a total of 200 amp hours?

Will it pull from each battery equally?

I hate to have battereis that are from different companies, but a new HSKY is $2500, and the LifePower is $1499

For the life of me I can't figure out why there is a $1000 difference between those batteries...

itzcoming said:

Do you mean the cells the same voltage, nominal?

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Yes. Cell count and voltage, e.g., 16S LFP battery.

itzcoming said:

The HSKY is 103 amp hours
The LifePower from Signature Solar is 100 amp hours.

When connecting will I have 204 total amp hours, or will the smaller battery throttle it back to a total of 200 amp hours?

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203 based on my math (103 + 100).

itzcoming said:

Will it pull from each battery equally?

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If you connect as I described, close enough to equal to not matter. You might see a 10A total difference between them, but they should work well within specification if you're not overloading them.

itzcoming said:

I hate to have battereis that are from different companies, but a new HSKY is $2500, and the LifePower is $1499

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No reason to.

Hey, glad to help you out. Both of these batteries have the same chemistry, so as long as the voltage and other parameters match up you should have no issues. Just a heads up though, there is no closed loop communications. If you have any other questions, please let me know!

@itzcoming

AlexFromSignatureSolar said:

Hey, glad to help you out. Both of these batteries have the same chemistry, so as long as the voltage and other parameters match up you should have no issues. Just a heads up though, there is no closed loop communications. If you have any other questions, please let me know!

@itzcoming

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Thanks for the answer @AlexFromSignatureSolar . Closed loop between 2 battery companies is extremely rare and likely not needed but you can definitely use the batteries together!

Thanks for the replies everyone!
Now all I have to do is get a LifePower and get them wired together.

I should fully charge the Big Battery and the LifePower, then connecting them, correct?

What is "Closed loop communication"?

Oh, and does anyone know why Big Battery is SO expensive? Mine doesnt even have bluetooth.

There's no problem doing that. I have two HSKYs running in parallel with another LiFePO4 pack without issue. You'll just need to be aware that the current sharing won't be exact between the two.

What are the ramifications of that?

itzcoming said:

What are the ramifications of that?

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The max discharge and charge rate of all of them in parallel will be less than the individual max discharge/charges rates added together

niktak11 said:

There's no problem doing that. I have two HSKYs running in parallel with another LiFePO4 pack without issue. You'll just need to be aware that the current sharing won't be exact between the two.

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Could you post a picture of how you have these wired together? Since server rack batteries and big battery have such different form factors I'm thinking the wires between them will be fairly long...

itzcoming said:

Could you post a picture of how you have these wired together? Since server rack batteries and big battery have such different form factors I'm thinking the wires between them will be fairly long...

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They are all connected to a big battery parallel box. The big batterys are each connected to it with 3ft 6AWG wire and the other pack is connected to the parallel box with 5ft 2AWG wire.

Reviving this thread because I have an issue. I sucessfully connected the new lipo4 48 battery to a bus bar with my already existing 48 volt HUSKY battery. Everything has been working perfectly for months.. I did give each battery a full charge before connecting them to my system.
Yesterday I noticed that the LiPo4 battery was only charing to the third LED when the system showed a full charge.
The batteries are in an enclosure that has a path to the inside of my home. That way the temp stays cooler in the summer and warmer int he winter.
Today I looked at them. The inverter (growatt 3000) said 52.5 volts. Each battery registered the same. But the Lipo4 battery LEDS were all the way down to one light. MyVictron battery monitor said I used 90 of my available 203 amps. Also, the red LED alarm light is flashing.
I'm thinking that since all the voltages between the two matched, maybe I have a cell in the LiPo4 battery that is low. I've disconnected the HSKY and am just charging the LiPo4 to see if I can get all 4 LEDS to light up.

It could have been working this way for months, I down' know.

Ideas?