Smart Blue not reaching charge voltage

DIY
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1

Hi all.

I’ve just installed a 30A BlueSmart charger in my van. The battery is a Fogstar 305Ah. The charger has been running for a while on a bulk charge but the charge voltage is showing as 13.65v approx. Amps are showing as 30 which is good. I wanted to ask about the voltage though - should it not be higher? I’ve adjusted the settings to the Fogstar recommendations but it was the same on the default setting. I’d have thought the voltage would be up over 14v when charging - I’ve the battery charge settings at 14.2v. Can anyone please give their opinion if this is fine or if not, what the issue could be?

I’ve checked everything that I can with my last guess being that perhaps that the earth that I’ve run to the van chassis isn’t as good as it can be. It’s a 16mm2 cable that’s about 1.5m long. For all the rest of the wiring I’ve slightly oversized everything to allow room for expansion.

Thanks in advance for any tips.

2

No, your expectation is wrong, charging a 305Ah battery at 30A the battery will not reach 14.0V until the very end of charge. Lithium behave very differently to lead acid. If this is the first charge you will need to add perhaps 180Ah which will take 6 hours and the voltage will only increase in the last 2 hours.

Here is a chart for the first charge of my 300Ah battery at 60A, so twice the charge rate of yours. At 30A rate you will get to a higher SOC before the voltage starts to rise.

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Hi.

Thanks for reply.

That’s great news and such a relief as I was so confused by it. It’s my first experience with a lithium battery as you can probably tell from what I was expecting.

Thanks again,
R.

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