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Thread Tools Display Modes
 
Old 05-21-2018, 03:16 PM   #1
Mini-Skoolie
 
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Battery Charge Level Display?

Hi all,

We're at the point now where we have our solar system completely set up and are now powering appliances directly inside the vehicle. Very exciting!! and thank you for everyone's help answering my questions.

I am wondering however the best digital display metre that can perhaps tell me the % our batteries are at?

Unsure how accurate they are, but if anyone knows a quality digital metre that would be amazing.

Thanks so much!

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Old 05-21-2018, 04:10 PM   #2
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Tri-Metric 2030-RV from Bogart Engineering is a good one. Almost too much/too 'configurable' for some folks.

Victron BMV-700 is not as flexibe/tunable but is a reasonable product.
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Old 05-21-2018, 04:29 PM   #3
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Quote:
Originally Posted by JDOnTheGo View Post
Tri-Metric 2030-RV from Bogart Engineering is a good one. Almost too much/too 'configurable' for some folks.

Victron BMV-700 is not as flexibe/tunable but is a reasonable product.
Ah yes I have heard good things about the tri-metric. Sounds like a good one. Thanks!
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Old 05-21-2018, 04:34 PM   #4
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I have the Trimetric JD mentioned. Nice piece of gear but if you want a really accurate gauge of your state of charge, assuming FLA batteries, you need one of these:

https://www.amazon.com/OTC-4619-Prof.../dp/B0050SFVHO

The Trimetric will show you voltage, amps in, amps out. It is "guessing" at state of charge.

The hydrometer is an essential tool if you want to get a reasonable life span out of flooded lead acid batteries.

Here is a good read that demonstrates using the hydrometer:

https://www.solarpaneltalk.com/forum...your-batteries

https://www.solarpaneltalk.com/forum...tteries-part-2
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Old 05-31-2018, 03:51 PM   #5
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Quote:
Originally Posted by PNW_Steve View Post
I have the Trimetric JD mentioned. Nice piece of gear but if you want a really accurate gauge of your state of charge, assuming FLA batteries, you need one of these:

https://www.amazon.com/OTC-4619-Prof.../dp/B0050SFVHO

The Trimetric will show you voltage, amps in, amps out. It is "guessing" at state of charge.

The hydrometer is an essential tool if you want to get a reasonable life span out of flooded lead acid batteries.

Here is a good read that demonstrates using the hydrometer:

https://www.solarpaneltalk.com/forum...your-batteries

https://www.solarpaneltalk.com/forum...tteries-part-2
what if you have AGM batteries?

I am looking at some 200 amp hour 6 volt AGM batteries from wholesalebatteriesdirect for $220 each it seems like this is a good deal for AGM and 200 amp hours compared to the more common FLA 6 volt providing 100- 105 amp hours at $110 each with 10% off for p/u in store at batteriesplus. BUT, one site says the amp hours are for the cheaper battery is 230 amp hours *for 20 hour* Is that the same standard that is used to measure the amp hours of the FLA batteries? They weigh about the same amount, which makes me question that.
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Old 05-31-2018, 04:29 PM   #6
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Quote:
Originally Posted by 2martins View Post
what if you have AGM batteries?

I am looking at some 200 amp hour 6 volt AGM batteries from wholesalebatteriesdirect for $220 each it seems like this is a good deal for AGM and 200 amp hours compared to the more common FLA 6 volt providing 100- 105 amp hours at $110 each with 10% off for p/u in store at batteriesplus. BUT, one site says the amp hours are for the cheaper battery is 230 amp hours *for 20 hour* Is that the same standard that is used to measure the amp hours of the FLA batteries? They weigh about the same amount, which makes me question that.
You should be able to find 200-220A/H 6v FLA's for $85-$130.

Sam's Club has GC2's for around $85 and Trojan T105's can be had for around $130.

Regarding SOC of AGM's. I don't know the answer to that question. A quick Google search yielded:

State Of Charge (SOC) for AGM Batteries
It will be pointed out that SOC can only be measured by voltage when the battery bank has been at rest for at least 3 hours. At rest means not being currently charged by a charger/solar panels or discharged by devices attached to the battery bank. Being at rest will allow the batteries to stabilise and thus give a more accurate reading when measuring by voltage.

For greatest life the battery bank should not discharge less than 50% SOC
100% SOC 12.8 volts or greater
90% SOC 12.7 volts
80% SOC 12.6 volts
70% SOC 12.50 volts
60% SOC 12.30 volts
50% SOC 12.20 volts
40% SOC 12.00 volts
30% SOC 11.80 volts
20% SOC 11.70 volts
10% SOC 11.50 volts
0% SOC 10.50 volts


This assumes a 12 volt battery bank. Double their numbers if you have a 24 volt battery bank.

Yes, you want to be looking at the 20hr rate when sizing/comparing batteries.
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