It is possible that the damage occurs when the battery is full and there is (almost) no load on the generator. You will allow 2 amps, you say. 140V, out 24V.

When you put 2 packs in series, you simply place double the number of cells in series. So what voltage should I charge it at and for approx how long?

You could add a small circuit to limit the current. Upon disconnecting , many things can happen since the battery is no longer connected.

hi thanks a lot for the information you are providing.

For instance, when a 100-amp charger is linked parallel to a 50-amp charger, the charge current will not be evenly distributed over both.

The battery charger must have the same voltage as the battery, i.e. Please help me It’s very important for me to know.

Point 2: One cell only; connect voltmeter.

Andre. So if you say that my option isn’t as much good, where can i get a charger that is more efficient?.

It is a bit surprising that you can charge a 2Ah(=2000mAh) battery using a 500 mA and a charging time of 3 hours.. 3h * 500mA = 1500 mAh.

so if I use a high mah charger will it damage the battery .also will the current of 400mah battery will increase beyond 400 mah if it is overcharged. Other charge characteristics can also be easily installed. Do they reside in the device itself or in the charger? If you are sure the voltage stays there and does not rise, you can keep it connected forever. In this case, make sure that the battery isolator or Battery Mate is powerful enough to simultaneously handle both the battery charger and alternator current.

Make certain that none of the cells connected in series exceeds this voltage. are too high. I bought the Computer off craigs list and it came with the charger, and my cats chewed on the cord so, I assumed it was giving to much power.

4 branches means each branch gets 0.5 amp. If current has become low (guessing 10…20mA) with 13.8V, the battery is full.

I have only tested with this combination and sees a drop of around 1V across the resistor and now the battery voltage is 12.8.In that case,either I have to get rid of resistor or slightly increasing the DC Output of the converter. 1) I connect them in series to make a 72V 40Ah unit, and charge this pack using a suitable charger for 72Volts. I can only set voltage… (and noise offset)

Hi Shreekant,

but within a minute or so, you voltage will be above 12, and the current will drop to a lot lower value; at 12V battery voltage it will be 0.55 amp; at 13V voltage it becomes 242mA.

I have connected battery in the output of three phase converter which is connected to grid.

When multiple large battery chargers are parallel switched, the available 230-volt connection is often insufficient. Of course both battery packs must be identical.

It contains 3 X Li-ion 3.7V 1500mAh cells. If your charger outputs e.g. 1: If your plan is to give the battery some extra charge and then disconnect the charger, then you can connect a resistor in series with the battery and the charger. This is in accordance with the advice of most battery manufacturers. Imho, 1.2V Li-ion does not exist, unless maybe someone placed some circuitry inside the battery to reduce the output voltage.

If it hasn’t, you better limit the current indeed. But that will be hard, maybe impossible.

the battery is Li-ion which has nominal voltage of 3.7 volts,10 Ah.

It probably won’t draw much current; maybe only a few mA.

If this is all you have, you can measure at least 6 points of the V/I curve, and then connect the points with a line to get the complete V against I curve. Is it safe to use my old chromebook charger on the new one? Disconnect the charge.

1. your upconverter is current limited. From you questioning I understand that you DC/DC can deliver 250mA.

I have 50 lead acid batteries and each one is 12 V 7Ah. 1V means 10 amps. This will require some experimenting.

But I think it is quite harmless to test and check currents. Plz help..

The engine start and run at 2,000rpm for 10 minutes every 4-6 hours. Then you get a 15V very powerful charger. Will there be any conflict if the alternator is supplying 12v at the same time as the solar panel to battery 1 and 2? For example, if your old charger provides 19.5V, then you can use a charger that provides 20.5V or 18.5V.

Andre, Hi

You can google for a suitable charger. But you can use the 5V mobile charger anyway; just put a resistor in series; value 12 ohm, 1/4 Watt. A battery charger measures as standard the voltage at its output terminals. The only concern in this story is the current. But you cannot keep it connected; you must manually terminate the charge as soon as the current has dropped to a certain value. a) the charger studying the battery voltage and current to regulate the delivered voltage and current, Or The article I mentioned says: terminate the charge when the current has dropped to 3% of 64 in your case = 2Amp approx. When they are in parallel, the total voltage is 12V. Since it is 1 ohm, the voltage over the resistor = the current through it. 2) i have a 12V battery of capacity 10Ah..can i charge it using a 250mA current which is provided by the DC DC booster circuit..? Caution: if your battery is very empty, it might draw more current the first minute(s) than is good for it. A suitable charger will give a higher voltage than 6V so it can push current into the batteries. A 1W or 2W type will be better. You want to know max load current with the charger connected? And the linear regulators have some voltage drop, so the 12V might be a bit short. In your case you need 13.5…13.8V (2x3x2.25V) if you want to keep them connected all the time (float charge), or higher (up to 14.5V) if you plan to terminate manually after a few hours.

No problem.

My 12v 7Ah battery current voltage is 2.7v.

Easier solution? some questions first: what is the power of the motor (how much current)? You can try that if the current described above stays low. Can you explain rapid pulse charging? No need to go to a higher voltage.

@Glen Kinder: Can your amplifier work on 26V?

During periods when the battery is resting, an absorption cycle lasting one hour will take place every 12 days to ensure that the battery stays in perfect condition. Those 9V cells, unless it is a fast charge type, prefer 1/10 of the capacity as charge current, so that would be 29mA, for 15 hours.

I have read that one should be careful about using chargers that are not approved by the device mfgr but if the limiting circuitry resides in the device (i.e., that which prevents overcharging), my thought is that a charger with higher output capacity (e.g., 500ma vs. 3a @5v) might be the only consideration since a fast charge could be detrimental to some batteries. Connecting a lithium battery to a DC voltage that can deliver a high current is dangerous; it can kill the batteries and they might even explode.

Example: Take an empty 200 Ah battery, a 50-amp battery charger and a connected load consuming 10 amps. 2A or 3A Intelligent charger But if it is an electronic adapter (not a transformer but and electronic switching circuit), chances are good that it is current limited and won’t get damaged. This applies when the distance is three metres at most.

What to do? @Ramesh Subramani:
Thanks. Or you can use 2 pcs 1.5 ohm in series, each 10W.

But you will buy like a 100USD for that DC/DC converter… LT1076 + surrounding parts will be around 15 USD. Success!

But when i want the battery to give 400 kW in an hour the system becomes unstable.

When they are empty, you actually should charge with 1/10C = 40mA, during 14 hours. 90W would work (given same voltage) but not recommended. I suggest you read the article on this site about charging lead acid, BU-403. Off-voltage adapters will work for a while but ultimately cause issues like video card failure. While charging, the current limiter will limit the current to 12.5A or whatever you choose. If the chargers and sensors are properly linked, the charge current will be evenly distributed over the connected chargers. If you have a small solar panel, you could try to limit the current to a much lower value, like 100mA or so.

A 230V 100W light bulb has a resistance of R=(VxV)/P = (230x230)/100= 529 ohm.

I didn’t understand. These (thin) cables ensure that the battery charger measures the voltage directly on the positive and negative terminal of the battery instead of on the output terminals of the battery charger. I did post another day about this problem. When higher than 15V: risk for damage.

RPS1230SWD is perfect for charging 12V lead acid. If your AC/DC converter is current limited, there won’t be any problem. I’m not from USA so i would really thank if you can give a web page or some dealers that ship worldwide and be trustful obviously, thank you again Andrew, Regards, Hi - I have a 36v 1.6 amp. will a 3000mah battery provides 3000mA per hour. If you apply 4.6V and the current drops to a low value, the battery is full. 12v adapter with battery charger pin - 20no’s You can connect the batteries, and they will charge for sure, but carefully measure the current and voltage.

I have a 12v solar controller (that came with my solar panel), a 100W solar panel, and a 222Wh, 20Ah/11.1V lithium ion battery with ‘solar panel charging support’ The battery doesn’t seem to charge if I plug solar panel through the controller (12V/12A controller) and the controller into the battery - the battery whistles at me and the controller shows no amps passing to the battery. 20Ah simultaneously using two suitable chargers of 72 volts? Your machine requires 120W charger. It is important to observe these voltage limits. Hi Anthony Adverse,

When parallel connecting multiple battery chargers, we recommend that they be of the same model, type and charge capacity. I don’t even know if it’s a plausible theory.