Chosen Solution

Replaced DC-in and DC-to-DC boards. Have new battery and new power adapter. Powerbook will not start. It could be the new (cheap) adapter malfunctions. Last time I tried testing one, I discovered the circular metal thing on the outside is just a shield, whose purpose is to make poking multimeter probes at the tiny separated sections of the male pin about impossible without arcing! So, how can I test the adapter with a meter? It could be the battery. I don’t know whether they ship charged at all. Maybe my old one is fine! They have a connector with six conducting slots. I don’t want to damage the battery or my meter. How do I test the batteries with a meter? It could be I messed something up installing those boards, or maybe another part is faulty. I’ve already spent too much on these pieces! If the adapter or battery is faulty I can exchange them. If they’re both fine, I’ll dismantle the laptop to check my previous repairs for damage. Or I’ll give up!

dzturbd, here is the pinout of the power adapter. tip not connected tip/ring negative ring + 24V shield connected to negative with a .5MΩ R

To test the battery, use a voltmeter to locate the positive and negative battery terminals and establish the polarity. Usually it is the outside (L+R) contacts that are positive and negative.Connecting the voltmeter to the outer terminals, take a 100-Ohm resistor (other values may also work), tie one end to ground, and with the other end touch each terminal while observing the voltmeter. If no voltage appears, the battery may be dead. The 100-Ohm resistor is low enough to engage a digital circuit and high enough to protect the battery against a possible electrical short. check here for more info. As for your battery pinout, depends on which PB you have. For that the last 4 digits of your serial number might come in handy.

I agree with oldturkey03. The basic way of testing a battery is to look for the positive and negative terminals. Then use the probes of a voltmeter or a multimeter to connect with the right terminals. Grounding a resistor is needed to give a small load to the battery that will help you test it. If your device don’t provide a result, it means the battery is dead or your doing it wrong. Here is the resource where this website provides more.

To test the battery you should have a voltmeter if the current is flowing good between positive and negitive nodes than your battery is working good. I always use voltmeter to check my trolling motor battery.

Still very unclear as to how to check various of the ipad air, power packs i have which function at different levels! ( but which if course they wont tell you pre purchase!!)

thanks for this i like trollingmotorbattery