DIY Charger?

[Derekgroves]

I have a MiniPro that I picked up at an estate sale, which of course came with a dead battery and no charger.

I’ve replaced the battery but need a charger and don’t mind cobbling one together to save the money.

I do have a GX12-4 female connector, and a few AC adaptors lying around, one pushing 1.75amps and 19v.  I don’t care if it takes overnight to charge, or even 2 days if it saves me the $40 I don’t have right now.

Can I mod an AC adaptor like this with the GX12-4 connector I have? Per this link.... http://chargedoctor.fr/en/charger-customization/

Also, would one of these work but with my GX12-4 on the end? I have one of these I can use: https://www.amazon.com/Schumacher-CR-2-Universal-Battery-Charger/dp/B005F1YJA6

[mrelwood]

First, it's ok not to have learned the basics on electricity. But as you haven't, you definitely should not do any modifications to any electric devices. There are so many ways you can hurt yourself or burn down your house. Or at least toast the device itself.

Regarding the links:

1. AC adaptor is not a charger.
2. Would not charge. Might melt and/or burn though.

What a surprising situation that you bought a vehicle, then a whole battery for a few hundred $, and now missing $40 for a charger. But as it is, the only thing you can do is wait until you have the $40 for an actual MiniPro charger.

[Keith]

7 hours ago, Derekgroves said:

Also, would one of these work but with my GX12-4 on the end? I have one of these I can use: https://www.amazon.com/Schumacher-CR-2-Universal-Battery-Charger/dp/B005F1YJA6

I can only second @mrelwood‘s comments. Lithium batteries have VERY specific requirements which if not met can and will result in the battery catching fire - part of the reason for the Hoverboard fires a year or two ago ( the other being crap cells taken out of recycled Laptop batteries). Lead acid battery chargers, as you have specified above, are very much cruder devices that usually have no voltage or current stabilisation built into them at all.

Lithium Ion batteries require constant current/constant voltage chargers. Ideally current should be capped at 1/2C and absolutely never more than 1C until the maximum voltage of 4.2V/cell is reached and then must not exceed that voltage at all under any circumstances. Full charge is indicated merely by the current having dropped to some fraction (say 5 or 10%) of the original charge current.

If I lost you at 1/2C that means, if a battery is 1Ah in capacity, it should be charged at a constant 500mA. Additionally either the charger or the battery’s inbuilt protection circuitry should prevent the battery being charged if any cells are much below 2.5V as, at that point potentially, metallic lithium whiskers have started to form and begin shorting out the cell - making it again possible for the cell to overheat if charged and catch fire.

[JES]

You should have bought the charger first. I is highly unlikely the battery is bad. Unless the battery is actually defective they have a long life. Especially considering the Minipro has only been around for about two years. Search the forum, there is a process for rebooting the removed battery if it won’t charge when you get a charger. Buy the charger from More4mini, it will charge the battery to 100% giving some more range. The original charger for US units charges to less than 100% for increased battery life. You will be fine will the lifespan charging to 100%. It is recommended not to store the battery charged to 100% for extended periods, months.