Semtex Posted July 8, 2005 Report Share Posted July 8, 2005 I think I'm more confussed now than I was to start with. The instructions that came with my trickle charger from Wolf Armouries said to charge my 8.4v 1050 mah Ni-MH batteries for 4 hours for a full charge. No indication of what the first charge should be ? I know it should be longer but how much longer ? I bought a discharger as well and have discharged both my batteries to start with. I like most people am worried about frying my batteries, as you all know these things aren't cheap. I am therefore looking to invest in a charger that will change my batteries and then shut off once they are fully charged. This investment has to be more cost effective than buying new batteries every time I get a charge time wrong and over cook them. So can anyone recommend a charger that will charge my batteries and then shut off when they are done. I have read many post with people talking about chargers but most posts sound just as confused with using these intellegent charges as the people using non-intellegent ones. Is there a good intellegent charger out there that will allow me to set the mah of my batteries and leave it safe in the knowledge that my batteries will only be charged until they are full ? Any help would be much appreciated. Cheers Rich Link to post Share on other sites
Architect Posted July 8, 2005 Report Share Posted July 8, 2005 All "Pulse" chargers will do that for you. They cost around £40 and are available from most airsoft shops. Link to post Share on other sites
Semtex Posted July 8, 2005 Report Share Posted July 8, 2005 Ok, I'll sort out getting one. Any idea how long the first charge should be for an 8.4V 1050 mah battery ? Cheers Link to post Share on other sites
Architect Posted July 8, 2005 Report Share Posted July 8, 2005 The first charge should always be on slow charge, which varies from about 200mA - 300mA i think. You can check the start of this thread for the battery charging formula for slow charges to find out how long it will take. Link to post Share on other sites
DBACPhoenix Posted July 8, 2005 Report Share Posted July 8, 2005 Ok, I'll sort out getting one. Any idea how long the first charge should be for an 8.4V 1050 mah battery ? Cheers <{POST_SNAPBACK}> The rate and time you slow-charge a battery will vary depending on the cells. If you want an accurate answer, I suggest checking the spec sheets from the manufacturer on those cells. Otherwise, a good rule of thumb is to charge at C/10. In your case you would charge at 105mA or somewhere near that point. Phoenix Link to post Share on other sites
davedawg123 Posted July 16, 2005 Report Share Posted July 16, 2005 --------------------------------------------------------- Total Battery Capacity (mAh) divided by Charge Rate (mA) multiplied by 1.4 --------------------------------------------------------- <{POST_SNAPBACK}> Hi, I have a question regarding the charging of an 8.4V, 3300mah NIMH battery. By the above equation, my charge time should be approximately 19.8hrs with a 300mA battery charger. But, my battery was warm at around 16 hours. Should I stop the charge after I notice the battery becoming warm or should I leave it for another 4 hours? Thanks. Dave Link to post Share on other sites
DBACPhoenix Posted July 16, 2005 Report Share Posted July 16, 2005 Hi, I have a question regarding the charging of an 8.4V, 3300mah NIMH battery. By the above equation, my charge time should be approximately 19.8hrs with a 300mA battery charger. But, my battery was warm at around 16 hours. Should I stop the charge after I notice the battery becoming warm or should I leave it for another 4 hours? Thanks. Dave <{POST_SNAPBACK}> Yes, you should remove your battery once it becomes warm/hot. I personally do not advocate the usage of the "formula" since it is more of a generalized and inaccurate way to charge a battery. With the many charging methods out there, the only reliable way to charge your battery if you do not have auto cut-off is to test it via Volt meter or by touch. If your only method is touch, then time how long it takes for the battery to get warm/hot and remove it from the charger. In general, Sanyo cells are spec'd out for 14-16 hours for slow charging (C/10 or less), so in your case your battery has fallen under this time range so it would be safe to say it is charged. Phoenix Link to post Share on other sites
davedawg123 Posted July 16, 2005 Report Share Posted July 16, 2005 Thanks Phoenix, that was very helpful. Yeah, I assumed as much and removed the battery from the charger when it became warm. I just wasn't certain. Link to post Share on other sites
PaNdeMiC Posted July 16, 2005 Report Share Posted July 16, 2005 I've got a question about using more then only one battery. I'm planing to buy an intellect 9.6V 1200 mAh AK mini type battery, but since it would only last for about 1500 BBs I guess I should buy another one as a spare battery. Although the charging time for such a battery should be only around 5-6 hours (assuming the output is 300mA), charging both batteries would take about 11 hours, which is still not very much compared to the charging time of a 3000mah large type battery, but nevertheless would that make spontaneous skirmishing rather impossible. So I was wondering whether I should buy another charger (~30£ ) or if there's maybe even a possibility to charge two batteries at the same time with only one charger. Link to post Share on other sites
DBACPhoenix Posted July 16, 2005 Report Share Posted July 16, 2005 I've got a question about using more then only one battery. I'm planing to buy an intellect 9.6V 1200 mAh AK mini type battery, but since it would only last for about 1500 BBs I guess I should buy another one as a spare battery. Although the charging time for such a battery should be only around 5-6 hours (assuming the output is 300mA), charging both batteries would take about 11 hours, which is still not very much compared to the charging time of a 3000mah large type battery, but nevertheless would that make spontaneous skirmishing rather impossible. So I was wondering whether I should buy another charger (~30£ ) or if there's maybe even a possibility to charge two batteries at the same time with only one charger. <{POST_SNAPBACK}> If both batteries are the same, you can connect them in parallel and charge them together. I have charged up to 20 8.4v 600mAh batteries at a time in under 10 hours. Definatly cuts down on swapping them out all the time. Phoenix Link to post Share on other sites
PaNdeMiC Posted July 16, 2005 Report Share Posted July 16, 2005 Ah nice, do I need some sort of adapter for this? Link to post Share on other sites
DBACPhoenix Posted July 16, 2005 Report Share Posted July 16, 2005 Ah nice, do I need some sort of adapter for this? <{POST_SNAPBACK}> Not really... you just need to connect all of the red leads together, and all of the black leads together. If you already have connectors on the packs and you don't want to remove them, then you will need to make your own adapter with opposing end connectors. Phoenix Link to post Share on other sites
R22Master Posted July 16, 2005 Report Share Posted July 16, 2005 --------------------------------------------------------- Total Battery Capacity (mAh) divided by Charge Rate (mA) multiplied by 1.4 --------------------------------------------------------- <{POST_SNAPBACK}> Hi, I have a question regarding the charging of an 8.4V, 3300mah NIMH battery. By the above equation, my charge time should be approximately 19.8hrs with a 300mA battery charger. But, my battery was warm at around 16 hours. Should I stop the charge after I notice the battery becoming warm or should I leave it for another 4 hours? Thanks. Dave <{POST_SNAPBACK}> Ummm, you mis-calculated... 3,300mAh (Total Battery Capacity) divided by 300mA (Charge Rate) multiplied by 1.4 = 11 multiplied by 1.4 = 15.4 hours charge time No wonder your battery gets warm after 16 hours Link to post Share on other sites
davedawg123 Posted July 16, 2005 Report Share Posted July 16, 2005 Haha... don't I feel stupid. I saw this thread a while back and remembered it being *1.8 not 1.4 and assumed just as much when I came back to read it again. I was wondering why the charge time was so damn high. Thanks R22. Link to post Share on other sites
R22Master Posted July 16, 2005 Report Share Posted July 16, 2005 You're welcome Link to post Share on other sites
PaNdeMiC Posted July 16, 2005 Report Share Posted July 16, 2005 Not really... you just need to connect all of the red leads together, and all of the black leads together. If you already have connectors on the packs and you don't want to remove them, then you will need to make your own adapter with opposing end connectors. Phoenix <{POST_SNAPBACK}> Just to make sure I got this correctly: Do I have to charge the two batteries with doubled amperege output (~600mA) and stick everything like this? Link to post Share on other sites
DBACPhoenix Posted July 16, 2005 Report Share Posted July 16, 2005 Just to make sure I got this correctly: Do I have to charge the two batteries with doubled amperege output (~600mA) and stick everything like this? <{POST_SNAPBACK}> hehe... nice picutre.. And yes, double amperage so each one gets ~300mA. Link to post Share on other sites
PaNdeMiC Posted July 16, 2005 Report Share Posted July 16, 2005 hrhr thx, it's no beauty but it serves the purpose Link to post Share on other sites
PaNdeMiC Posted July 17, 2005 Report Share Posted July 17, 2005 Well, I've just read that charging batteries in parallel could damage the batteries, but that charging in serial would be ok: Charging two batteries in serial is OK, this is the case of 99% of chargers. But, charging in parallel is a very bad thing, because battery's internal resistance is not constant and varies between cells. If you charge two batteries in parallel, one might be still undercharged while the other is already overcharged because their resistance and other characters are different even if they are made in the same group by the same manufacturer. One battery gets more currents than other and reaches full state earlier. If charging stops as soon as one is full, the other is under charged. This result in short battery life between charges, but does not harm the long-term battery life as overcharging is avoided. Overcharging generates lots of heat and dry out batteries. source: http://www.fixup.net/tips/batt/ So wouldn't it be more safe to charge two batteries in serial? Link to post Share on other sites
R22Master Posted July 18, 2005 Report Share Posted July 18, 2005 You mean in "Series"? Yeah, it is better to charge two different packs in series as charging them in parallel will mean all of the charge goes in to the easiest pack to charge (the pack with the lowest internal resistance). That pack will then overcharge as the other charges very slowly, if at all. Remember, charging in series means you have to double the charge voltage (two 8.4v packs in series need to be charged at 16.8v as you are essentially charging 14 cells at once). Link to post Share on other sites
PaNdeMiC Posted July 18, 2005 Report Share Posted July 18, 2005 Ah thanks for your help. Well I was pretty confused whether it's "series" or "serial" cause some sites write serial (for example the page I quoted) and other series. But I can't find a charger that charges up to 20V so I guess I'll have to charge the separately or maybe in parallel. I had another question about batteries: How long can you keep a battery charged without discharging it? Does it damage the battery if you keep it charged for several days? Link to post Share on other sites
R22Master Posted July 18, 2005 Report Share Posted July 18, 2005 Depends on the battery. Ni-Cd packs will discharge over the course of a few weeks (when new) or a few days when old. Ni-MH packs can hold the majority of their charge for a year or more. If you are charging the two packs seperately and then using them in parallel, remember that you must charge them both to exactly the same level. Failure to do so will result in one pack failing before the other, and the pack still containing charge will actually start charging the dead pack while in use. This is damaging to the cells of the dead pack (although not too badly damaging). Just one thing best avoided if possible. A good charger that detects when each pack is fully charged and shuts off, will help you charge both packs to the same level Link to post Share on other sites
PaNdeMiC Posted July 18, 2005 Report Share Posted July 18, 2005 I think I wouldn't use them in parallel, I'd just use one as a spare battery in case the main one runs out of juice Edit: I assume this intellect battery is a Ni-MH one, since the 8.4 verion of this battery is Ni-MH. This means I should be able to charge the battery for instance a whole week before I use it, right? Link to post Share on other sites
R22Master Posted July 18, 2005 Report Share Posted July 18, 2005 Looks like a NiMH pack to me, so if it is - Yes - you can charge it a week before and it will only lose at most 5% of its power over the week. NOTE: That amount will increase as the battery ages, but given proper care, it will be over a year before you witness any effects. Link to post Share on other sites
Cal9000 Posted July 19, 2005 Report Share Posted July 19, 2005 ok. im a bit stuck here. maybe somebody can spell this out for me i have a 3300 Mah Ni-mH battery, which i've charged once at 300 MA for around 24 hours to condition it it fired about 5k rounds then died. fine i thought i then charged it on 600 MA for around 12 hours. it managed about 5 rounds then died?? which made no sence to me.. so i set it back to 300 MA and left it on over night, probably about 15 hours or so. again, it only managed about 5 rounds then died... so what am i doing wrong? thanks edit - its 8.4v Link to post Share on other sites
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