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Lithium Ion power packs

Lithium Ion power packs

Lithium Ion power packs

I had a question about lithium ion power packs. My company places monitors at construction site that are sometimes out at sites for months or years at a time. We have been using lead-acid batteries charged with solar panels and solar chargers to control charging to keep the monitors powered. This works pretty well, except the lead acid batteries can have some issues, and the wiring to connect to the batteries gets kind of annoying. We were thinking of using some of those lithium ion portable power packs you can get off of amazon instead, but the first few we have tried won't allow the power pack to be charging and discharging at the same time. We need to make sure that the power pack is supplying power to the monitors during the day while it is simultaneously being charged by a solar panel. I don't really know much about lithium ion batteries, so is this issue something that just happens or is there a way to work around this? Thanks.

RE: Lithium Ion power packs

That sounds like more of an issue with the charger. Your laptop has Li-ion batteries and it charges and runs at the same time, but it's likely that during charging, the power to run the laptop is coming from the charger and not the battery. This is one reason certain laptop charges are large and heavy, since they need to run a laptop and charge the battery at the same time.

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RE: Lithium Ion power packs

That's the reason. You can't get really good "fuel gauging" while charging and supplying power without a lot more electronics. The sure way is to charge the battery in isolation. Hence, the much bigger cord-warts so they can separately charge AND run the load (computers etc).

For your application you will need a bunch more technology to keep up the monitoring and keep the battery systems charged with the available solar power. Lead acid batteries can be charged up sort of sloppily and still do well. Not so with lithiums, slopply = fire, or damaged batteries.

Keith Cress
kcress - http://www.flaminsystems.com

RE: Lithium Ion power packs

A colleague ran into this and setup a dual battery solution. He'd run the circuit off Battery A while charging Battery B, and vice versa.


RE: Lithium Ion power packs

How's a stand alone charger;
1) accept the battery since LT batteries are all sorts of screwy shapes?
2) interface with the battery's internal custom BMS?

Keith Cress
kcress - http://www.flaminsystems.com

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